Laminated film for packaging materials, and packaging bag

Abstract

To provide a packaging bag which uses an environmentally friendly laminated film for packaging materials that saves petroleum resources and reduces carbon dioxide emissions, and has processing suitability and physical properties, especially durability, comparable to petroleum-based resin packaging bags.SOLUTION: A laminated film for packaging materials 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 a plant-derived ethylene by a high-pressure method. The laminated film for packaging materials has a biomass degree of as least 25% calculated from a measurement of radioactive carbon dating 14C.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a laminated film for packaging materials and a packaging bag, and more particularly, to a laminated film for packaging materials in which a film made of a resin composition containing a plant-derived low-density polyethylene resin is laminated, and a packaging bag using the film.

Background Art

[0002] For example, flexible packaging (light packaging) widely used as a packaging form for frozen foods such as dumplings, baked shumai, fried rice, and pizza is composed of a flexible packaging material made of a sealant film and a base material film. However, many of the raw materials for flexible packaging materials are derived from petroleum, and it is required to address environmental problems and conserve depletable resources such as petroleum. And, a packaging bag (for example, Patent Document 1) containing a biodegradable resin composition in which a polyolefin resin as a carbon-neutral material and a polymer having an epoxy group are each contained in a predetermined amount for the purpose of reducing the amount of petroleum resources used for packaging materials is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By including a biodegradable resin other than petroleum-derived raw materials in the resin composition constituting the packaging bag, the ratio of petroleum-derived raw materials can be reduced. However, such a packaging bag is 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 productivity and also difficult to improve durability.

[0005] Therefore, an object of the present invention is to provide a laminated film for packaging materials that is environmentally friendly by saving oil resources and reducing carbon dioxide emissions, and a packaging bag that uses the film and has processing suitability and physical properties, particularly durability, comparable to those of a packaging bag made of a petroleum-based resin.

Means for Solving the Problems

[0006] To solve the above problems, the present invention provides a laminated film for packaging materials, which is formed by laminating 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 a base film, and the laminated film for packaging materials has a biomass degree calculated from the measured value of radiocarbon dating 14 C of at least 25%.

[0007] Furthermore, the plant-derived low-density polyethylene resin is characterized by having a biomass degree of 10 to 100%.

[0008] Furthermore, 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.

[0009] Furthermore, the sealant film is composed of either (A) or (B) below using the resin composition containing 10 to 1 00% by weight of the plant-derived low-density polyethylene resin and 0 to 90% by weight of the petroleum-derived low-density polyethylene resin. (A) A single-layer structure in which the resin composition and the petroleum-derived low-density polyethylene resin are mixed (B) A multilayer structure in which the middle layer is a layer in which the resin composition and the petroleum-derived low-density polyethylene resin are mixed, and the outer layer and the inner layer are made of the petroleum-derived low-density polyethylene resin

[0010] Furthermore, it is characterized in that an intermediate layer is further provided between the sealant film and the base film.

[0011] Furthermore, the packaging bag of the present invention is characterized in that it is made using the above-described laminated film for packaging materials.

Advantages of the Invention

[0012] According to the present invention, there is provided a laminated film for packaging materials, in which 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 a base film are laminated. The laminated film for packaging materials has a biomass degree calculated from the measured value of radiocarbon dating 14 C of at least 25%. Therefore, it is possible to reduce the amount of petroleum resources frequently used as raw materials for the sealant film constituting the laminated film for packaging materials, and to suppress the carbon dioxide emissions derived from petroleum during the production and disposal of the film. Furthermore, since it is not inferior in physical properties to the petroleum-derived low-density polyethylene resin, it can be made the same as the manufacturing process of the existing laminated film for packaging materials, and the raw material can be switched without impairing the processability of the packaging material. Furthermore, the origin of the raw material 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 material can be confirmed from the time of film production to the time of disposal. Therefore, it is possible to provide a laminated film for packaging materials containing a low-density polyethylene-based resin with reduced environmental load, excellent production efficiency, and the ability to identify the origin of the raw material.

[0013] Furthermore, according to the configuration in which the plant-derived low-density polyethylene resin has a biomass degree of 10 to 100%, the usage ratio of petroleum-derived raw materials of the low-density polyethylene resin constituting the sealant film can be further reduced, the amount of petroleum resources used can be further reduced, and the carbon dioxide emissions derived from petroleum during film production and disposal can be further suppressed.

[0014] Furthermore, according to the configuration in which 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, even in the base film, the usage ratio of petroleum-derived raw materials can be reduced, the usage amount of petroleum resources can be further reduced, and the amount of petroleum-derived carbon dioxide emissions during the production and disposal of the laminated film for packaging materials can be further suppressed. And the laminated film for packaging materials has a tensile strength, a seal strength, and a stiffness suitable for a packaging bag, for example, a flexible packaging bag, and exhibits excellent processability.

[0015] Furthermore, the sealant film uses a resin composition containing 10 to 100% by weight of a plant-derived low-density polyethylene resin and 0 to 90% by weight of a petroleum-derived low-density polyethylene resin, and the following (A) and (B) (A) A single-layer structure in which the resin composition and a petroleum-derived low-density polyethylene resin are mixed (B) A multi-layer structure in which the middle layer is a layer in which the resin composition and a petroleum-derived low-density polyethylene resin are mixed, and the outer layer and the inner layer are made of a petroleum-derived low-density polyethylene resin According to the configuration which is any of the above, the usage ratio of the petroleum-derived low-density polyethylene resin constituting the laminated film for packaging materials can be reduced, the usage amount of petroleum resources can be reduced, and the amount of petroleum-derived carbon dioxide emissions during film production and disposal can be suppressed. In addition, since a petroleum-derived low-density polyethylene resin is used for the inner and outer layers constituting the sealant film as in (B), the film can be produced with the characteristics of the existing manufacturing process. Therefore, a laminated film for packaging materials having more excellent processability can be provided.

[0016] Furthermore, according to the configuration in which an intermediate layer is further provided between the sealant film and the base film, the laminated film for packaging materials can be configured to have various functions, for example, gas barrier properties.

[0017] Furthermore, since the packaging bag of the present invention is made using the above-described laminated film for packaging materials, the usage ratio of the petroleum-derived low-density polyethylene resin in the laminated film for packaging materials that constitutes the packaging bag can be reduced, reducing the amount of petroleum resources used and suppressing the amount of carbon dioxide emissions derived from petroleum during the production and disposal of the packaging bag. Furthermore, the usage ratio of petroleum-derived raw materials that constitute numerous disposable packaging bags on the market can be reduced. Furthermore, as described above, the processability and physical properties of the laminated film for packaging materials are not inferior to those derived from petroleum. Therefore, a packaging bag that saves petroleum resources and reduces the environmental load can be provided, which contains a plant-derived low-density polyethylene resin and has processability and physical properties, particularly durability, that are not inferior to those of petroleum-based resins.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

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Figure 7

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0020] Flexible packaging widely used in foods, daily necessities, etc. is composed of laminated films. Some laminated films have a sealant film (heat-sealing film) as a heat-sealing material for the inner surface of the flexible packaging laminated on a base film. For example, polyester-based resins are used as the material for the base film. On the other hand, low-density polyethylene (LDPE: Low Density PolyEthylene (PE-LD)) resin is used as the material for the sealant film. Low-density polyethylene resin is inexpensive and excellent in flexibility, transparency, extrusion coating property, heat adhesiveness, etc. y PolyEthylene(PE-LD)) resin is used. Low-density polyethylene resin is inexpensive and excellent in flexibility, transparency, extrusion coating property, heat adhesiveness, etc.

[0021] Thus, low-density polyethylene resin and polyester-based resin are often used as the materials for the laminated film. And these low-density polyethylene resins and polyester-based resins are manufactured using petroleum as a starting material. For example, low-density polyethylene is obtained by addition polymerization of ethylene (ethene) obtained by refining crude oil or the like under high-temperature and high-pressure conditions such as 300 °C and 2000 atmospheres.

[0022] On the other hand, awareness of environmental problems such as the depletion of resources such as petroleum and global warming due to an increase in carbon dioxide emissions is increasing year by year. In such a situation, the use of petroleum-derived low-density polyethylene resin, etc. means that a large amount of carbon dioxide fixed in petroleum is discharged into the atmosphere from the production to the disposal of petrochemical products, so no consideration is given to the environment.

[0023] Against such a background, the development of technologies for manufacturing plastics from plants, which are carbon-neutral and renewable resources, has been promoted, and a technology for producing polyethylene, which is the most widely used plastic, using biomass-based sugarcane as a starting material has been established (edited by the Processing Technology Research Group, Convertec 2009.9, P63-67). Note that carbon neutral means that the amount of carbon dioxide absorbed during plant growth is approximately the same as the amount of carbon dioxide emitted during combustion or decomposition, that is, it is neutral with respect to the amount of carbon circulation in the environment.

[0024] Next, the manufacturing process of the sealant film that constitutes the laminated film for packaging materials according to the present embodiment will be described. FIG. 1 is a flowchart illustrating the manufacturing process of a low-density polyethylene film derived from sugarcane, and FIG. 2 is a cross-sectional view schematically showing a sealant film containing a low-density polyethylene resin derived from sugarcane according to the present embodiment. Note that in the present embodiment, an example is shown in which sugarcane is used as a starting material for the laminated film for packaging materials and the packaging bag. However, the raw materials for the laminated film for packaging materials and the packaging bag according to the present embodiment are not limited to sugarcane, and any plant that can be used as a raw material for manufacturing a low-density polyethylene resin may be used. Furthermore, any renewable, bio-derived organic resource excluding fossil resources may be used.

[0025] As shown in FIG. 1, first, the sugar solution squeezed from sugarcane harvested in the field is heated and concentrated, and a mixture of crystallized raw sugar and sugarcane molasses 1, which is a non-crystalline substance, is separated by a centrifuge. Sugarcane molasses 1, which is a by-product generated during the production of this sugar, is used as a raw material.

[0026] Sugarcane molasses 1 is diluted with water to an appropriate concentration, fermented by yeast, and distilled to produce bioethanol 2 (step S101).

[0027] Bioethanol 2 is heated in the presence of a catalyst, and bioethylene 3 derived from plants is obtained by an intramolecular dehydration reaction (step S102).

[0028] Bioethylene 3 (monomer) is polymerized by the high-pressure method to obtain bio-low density polyethylene resin 10 derived from plants (step S103).

[0029] Thus, the bio-low density polyethylene resin 10 used for the sealant film constituting the laminated film for packaging materials according to the present embodiment is produced from ethylene derived from plants such as sugarcane as the starting material. It has been confirmed that ethylene and polyethylene derived from plants have the same quality as ethylene and polyethylene derived from petroleum. Therefore, the bio-low density polyethylene resin 10 can be produced in the same manner as when a low density polyethylene resin is produced from ethylene derived from petroleum. That is, the bio-low density polyethylene resin 10 can be produced by addition polymerization of bioethylene 3 under high temperature and high pressure conditions such as 300°C and 2000 atmospheres.

[0030] The bio-low density polyethylene resin 10 can have each physical property with a density d of 0.910 to 0.925 g / cm 3 and a melt flow rate (MFR) of 0.5 to 8.0 g / 10 minutes, more preferably 0.7 to 5.0 g / 10 minutes.

[0031] Note that the density (d, unit: g / cm 3 ) was measured in accordance with JIS K 6760 (1981) using a 1 mm thick sheet obtained by press molding at 150°C. Furthermore, the melt flow rate (MFR, unit: g / 10 minutes) 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 value of the melt flow rate is the amount (g) extruded in 10 minutes when a cylinder with a 2 mm diameter hole at the bottom is heated to 190°C and the object to be measured placed inside the cylinder is extruded by applying a load of 21.18 N. And since the viscosity at the time of melting increases as the degree of polymerization of the polymer increases, the value of the melt flow rate tends to decrease.

[0032] The bio-low density polyethylene resin 10 having these physical properties is used to manufacture a sealant film that constitutes a laminated film for packaging materials. In that case, if necessary, a petroleum-derived low density polyethylene resin 11 is mixed. The petroleum-derived low density polyethylene resin 11 is mixed so that the bio-low density polyethylene resin 10 is contained at an appropriate ratio of 10 to 100% by weight.

[0033] A resin composition containing the bio-low density polyethylene resin 10 at an appropriate ratio of 10 to 100% by weight and mixed with the petroleum-derived low density polyethylene resin 11 is formed into a film, thereby forming a film F1 containing bio-low density polyethylene as shown in FIG. 2 (step S104).

[0034] Although there are no particular limitations on the method for manufacturing the sealant film that constitutes the laminated film for packaging materials according to the present embodiment, melt extrusion molding is preferably used, and the inflation method, the flat die method, etc. are preferably used. Further, the sealant film may be processed into a multi-layer in which a plurality of layers are stacked, and in that case, the co-extrusion method is preferably used.

[0035] In the present embodiment, the bio-low density polyethylene resin 10 derived from plants obtained as described above is used to manufacture a sealant film that constitutes a laminated film for packaging materials. As a result, the present embodiment reduces the usage ratio of the petroleum-derived resin with respect to the resin composition used for the laminated film for packaging materials, reduces the consumption of petroleum, which is a fossil resource (depletable resource), and contributes to preventing global warming by reducing the amount of carbon dioxide emissions.

[0036] And in this embodiment, radiocarbon dating 14 Bio-low density polyethylene resin 10 having a biomass degree of 80 to 100% by C is used.

[0037] Here, it is difficult to distinguish between a resin derived from a plant (biomass) and a resin derived from petroleum based on physical properties such as molecular weight and mechanical properties , thermal properties, etc. Therefore, biomass degree is used as a general index for identifying the content ratio of the plant-derived resin in the resin composition. This biomass degree utilizes the fact that the carbon of the petroleum-derived resin does not contain (remain) 14 C (radiocarbon 14, half-life 5730 years), and this 14 The concentration of C is calculated by being measured by accelerator mass spectrometry. Therefore, by measuring the biomass degree of the film, it is possible to identify whether a plant-derived raw material has been used and the content ratio of the plant-derived resin in the resin composition.

[0038] In the first step of this biomass degree measurement, carbon dioxide generated by burning the measurement target sample and purified in a vacuum line is reduced with hydrogen using iron as a catalyst to generate graphite. Then, this graphite is mounted on a 14 C-AMS (Accelerator Mass Spectrometry) dedicated device (manufactured by NEC Corporation) based on a tandem accelerator, 14 Counting of C, as well as 13 Concentration of C ( 13 C / 12 C), and 14 Concentration of C ( 14 C / 12 C) are measured. From these measurement values, the ratio of the 14 C concentration of the sample carbon to the standard modern carbon is calculated. In this measurement, 14Oxalic acid (HOx II) provided by the National Institute of Standards and Technology (NIST), which is a standard sample for

[0039] In this embodiment, a sealant film having such a biomass degree is used. And, from the case where all were petroleum-derived resins, in this embodiment, a bio-low density polyethylene resin 10 having properties equivalent to those of petroleum-derived materials is mixed (substituted) with a petroleum-derived low density polyethylene resin 11. As a result, in this embodiment, it is possible to suppress the amount of carbon dioxide emissions derived from petroleum during the production or disposal of the sealant film.

[0040] Furthermore, in this embodiment, as the bio-low density polyethylene resin 10 contained in the resin composition, a plant-derived low density polyethylene having a density d of 0.910 to 0.925 g / cm 3 and a melt flow rate of 0.5 to 8.0 g / 10 minutes is used. As a result, it is possible to produce a plant-derived sealant film having properties equivalent to those of petroleum-derived materials in an existing film production process. Therefore, the raw material can be switched without impairing the processability of the packaging material. And the plant-derived sealant film according to this embodiment is also equivalent to the petroleum-derived one in terms of durability.

[0041] Furthermore, in this embodiment, since the sealant film has a biomass degree calculated from the measurement value of 14 14C, using this biomass degree as an index, it is possible to identify the raw material origin of the low density polyethylene resin constituting the sealant film and confirm the origin raw material from the time of film production to the time of disposal.

[0042] In this embodiment, the melt flow rate (MFR) of the bio-low density polyethylene resin 10 that constitutes the sealant film is preferably 0.5 to 4.0 g / 10 min. Furthermore, in order for the sealant film to exhibit 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-low density polyethylene resin 10 is more preferably 0.7 to 3.8 g / 10 min.

[0043] Next, in this embodiment, the above-described bio-low density polyethylene resin 10 and the petroleum-derived low density polyethylene resin 11 can also be used to form a sealant film as follows. That is, for the entire film, the sealant film can be formed in the following manners (A) and (B) such that the blending amount of the bio-low density polyethylene resin 10 is 10 to 100% by weight and the blending amount of the petroleum-derived low density polyethylene resin 11 is 0 to 90% by weight.

[0044] First, as shown in FIG. 2 described above for the film F1 of (A), it can be a single-layer structure composed of a resin composition in which the bio-low density polyethylene resin 10 and the petroleum-derived low density polyethylene resin 11 are mixed. Here, as described above, the resin composition that constitutes the film F1 contains 10 to 100% by weight of the bio-low density polyethylene resin 10 and 0 to 90% by weight of the petroleum-derived low density polyethylene resin 11. Therefore, when the content of the petroleum-derived low density polyethylene resin 11 in the film F1 is 0% by weight, the film F1 has a single-layer structure of the bio-low density polyethylene resin 10 alone.

[0045] FIG. 3 is a cross-sectional view schematically showing a film having a multilayer structure in which the middle layer is made of the bio-low density polyethylene resin 10. As shown in FIG. 3 for the film F2 of (B), it can also be a multilayer structure having a middle layer composed of a resin composition in which the bio-low density polyethylene resin 10 and the petroleum-derived low density polyethylene resin 11 are mixed, an outer layer made of the petroleum-derived low density polyethylene resin 11, and an inner layer. Here, similar to the film F1, the resin composition constituting the middle layer of the film F2 contains 10 to 100% by weight of the bio-low density polyethylene resin 10 and 0 to 90% by weight of the petroleum-derived low density polyethylene resin 11. Therefore, when the content of the petroleum-derived low density polyethylene resin 11 is 0% by weight in the middle layer of the film F2, the bio-low density polyethylene resin 10 forms a single-layer structure alone.

[0046] With such a configuration, the usage ratio of the petroleum-derived raw materials of the resin compositions constituting the films F1 and F2 can be reduced, and the petroleum-derived carbon dioxide emissions during film production, disposal, etc. can be suppressed. In addition, since the petroleum-derived low density polyethylene resin 11 is used for the inner and outer layers constituting the film F2 as in (B), the film F2 can be manufactured, used, and processed with the same characteristics as existing films. Note that the multi-layer film F2 can be manufactured by coextrusion molding.

[0047] Next, in the present embodiment, the above-described films F1 and F2 can be used to form a laminated film for packaging materials. FIG. 4 is a cross-sectional view schematically showing an example of the laminated film for packaging materials.

[0048] First, the laminated film 12 for packaging materials has a basic configuration in which the above-described films F1 and F2 are laminated with the base film 14 as the sealant film 13. And the laminated film 12 for packaging materials according to the present embodiment has a biomass degree calculated from the measured value of the radiocarbon dating 14 C of at least 25% preferably. With such a configuration, the usage ratio of the petroleum-derived low density polyethylene resin 11 constituting each of the films F1 and F2 of the sealant film 13 used for heat sealing can be reduced. And the laminated film 12 for packaging materials according to the present embodiment can save petroleum resources and suppress the amount of carbon dioxide emissions derived from petroleum during its production, disposal, etc.

[0049] Here, the Japan Bioplastics Association (JBPA) defines biomass plastics as "substances derived from renewable organic resources as raw materials, including substances obtained by chemically or biologically synthesizing a polymer material with a molecular weight (Mn) of 1,000 or more (excluding unmodified non-thermoplastic natural organic polymer materials)". And by including 25.0% by weight or more of the biomass-derived component in the biomass plastic or biomass-derived thermosetting plastic raw material composition, it can be made compatible with the "Biomass Plamarck".

[0050] The laminated film 12 for packaging materials may have an intermediate layer 15. By variously changing the intermediate layer 15, various functions can be imparted to the laminated film 12 for packaging materials, for example, gas barrier properties, impact resistance, pinhole resistance, fragrance retention properties, and chemical resistance. For the intermediate layer 15, for example, a barrier material that suppresses the permeation of water vapor and oxygen is used. As the barrier material, for example, a biaxially oriented polyamide (nylon (ONy: Oriented Nylon)) film or a biaxially oriented polyethylene terephthalate (OPET: Oriented PolyEthylene Terephthalate) film as a barrier resin may be used. Further, as the barrier material, for example, a vapor-deposited film in which a vapor-deposited film of silica, aluminum, or the like is formed on the surface of a barrier resin may be used. Further, as the barrier material, for example, a metal foil such as aluminum may be used.

[0051] The intermediate layer 15 is laminated by being adhered to the sealant film 13 by the adhesive layer 16 and adhered to the base film 14 by the adhesive layer 17. The materials of the adhesive layer 16 and the adhesive layer 17 are appropriately selected according to the type of the base material and the bonding method. Examples of the lamination (bonding) method include the dry lamination method and the melt extrusion lamination method.

[0052] As materials for the adhesive layer 16 and the adhesive layer 17 that become the laminate adhesive layer in the dry lamination method, there are polyester adhesives, polyether adhesives, etc. From the viewpoint of adhesive strength, it is preferable to use a two-component curable urethane adhesive. On the other hand, as materials for the adhesive layer 16 and the adhesive layer 17 that become the melt extrusion resin layer in the melt extrusion lamination method, there are polyethylene, polypropylene, etc. From the viewpoint of the adhesion to the base material depending on the type of the base material, it is preferable to use low-density polyethylene. Furthermore, the dry lamination method and the melt extrusion lamination method may be used in combination. The surface of each layer before being adhered may be subjected to surface modification treatments such as corona discharge treatment, ozone treatment, plasma treatment, etc. as necessary to improve the adhesion, and furthermore, an anchor coat agent or the like may be applied.

[0053] A printing layer 18 may be formed on any layer constituting the laminated film 12 for packaging materials. Printing of characters, figures, symbols, patterns, etc. is not particularly limited as long as it is a position visible from the outside of the packaging container, and surface printing may be used. In the layer structure illustrated in FIG. 4, a printing layer 18 is formed inside the base film 14. A white underlayer may be provided on the printing layer 18. The printing layer 18 is formed by printing using gravure printing ink or the like by printing methods such as gravure printing, letterpress printing, screen printing, transfer printing, flexographic printing, etc.

[0054] Note that an outer layer (not shown) may be further laminated on the base film 14 of the laminated film 12 for packaging materials.

[0055] Examples of the base film 14 include 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, poly aryl phthalate resins, silicone resins, polysulfone resins, polyphenylene sulfide resins, polyethersulfone resins, polyurethane resins, acetal resins, various resin films such as cellulose resins, and sheets can be used.

[0056] As the base film 14, a biaxially stretched polypropylene film (OPP: Oriented PolyPolypropylene) or a biaxially stretched polyethylene terephthalate (OPET) is preferably used. The biaxially stretched polypropylene film is excellent in moisture resistance, water resistance, chemical resistance, etc., and has high versatility and low cost. The biaxially stretched polyethylene terephthalate has low hygroscopicity and is excellent in aroma retention in addition to scratch resistance, heat resistance, water resistance, etc. And the laminated film 12 for packaging materials using these base films 14 has suitable tensile strength, seal strength, and stiffness as a packaging bag, for example, a flexible packaging bag, and exhibits excellent processability.

[0057] Furthermore, in this embodiment, the raw material of the biaxially stretched polyethylene terephthalate used for the base film 14 may be plant-derived.

[0058] Next, the manufacturing process of the plant-derived base film 14 constituting the laminated film 12 for packaging materials according to this embodiment will be described. FIG. 5 is a flowchart illustrating the manufacturing process of a plant-derived polyethylene terephthalate film. Here, an example is shown in which sugarcane is used as a starting material for the plant-derived polyethylene terephthalate film, that is, the bio-PET film F3 (see FIG. 1). However, the raw material for the bio-PET film F3 according to the present embodiment is not limited to sugarcane, and any plant that can be used as a raw material for producing polyethylene terephthalate resin may be used. Furthermore, it may be any renewable, bio-derived organic resource excluding fossil resources.

[0059] First, bioethylene 3 is obtained by going through steps S101 and S102 of FIG. 1 described above.

[0060] Bioethylene 3 is oxidized to obtain bioethylene oxide 4 (1,2-epoxyethane) (step S201). Bioethylene oxide 4 can be obtained, for example, by subjecting bioethylene 3 to pressurized heating at 1 to 3 MPa and 200 to 300 °C in the presence of a silver catalyst and subjecting it to catalytic gas-phase oxidation with molecular oxygen or a molecular oxygen-containing gas. Bioethylene oxide 4 may be produced by reacting bioethylene 3 with hydrogen peroxide or a peracid.

[0061] Bioethylene oxide 4 is hydrolyzed under an acid catalyst to obtain bioethylene glycol 5 (MEG: Mono Ethylene Glycol) (ethane-1,2-diol) derived from plants (step S202). Note that the biomass content of this bio-MEG 5 can be 100%.

[0062] On the other hand, paraxylene 6, which is a secondary product of petroleum, is oxidized and purified to a high purity to obtain purified terephthalic acid (PTA) 7 (step S203).

[0063] ​Bio-MEG5 and purified terephthalic acid (PTA) 7 are subjected to condensation polymerization to obtain a bio-PET resin 19 containing plant-derived raw materials (step S204). Note that 30% of the raw materials of the bio-PET resin 19 are Bio-MEG5 and 70% are purified terephthalic acid (PTA) 7, so the biomass content is 30%.

[0064] The bio-PET resin 19 is formed into a film to form a bio-PET film F3 (step S205). Then, the bio-PET film F3 thus obtained is used as needed for the base film 14 constituting the laminated film 12 for packaging materials. As a result, in this embodiment, the use ratio of the petroleum-derived resin in the resin composition used for the laminated film 12 for packaging materials is further reduced, the consumption of petroleum, which is a fossil resource (depletable resource), is further reduced, and it contributes to preventing global warming by reducing the amount of carbon dioxide emissions. More specifically, the bio-PET film F3 can reduce about 10% more CO2 than a petroleum-derived PET film throughout the entire life cycle from raw material procurement to disposal.

[0065] Note that 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 content is 20%. On the other hand, out of the molecular weight of 192 of the PET structural unit, the molecular weight derived from ethylene glycol is 60. Therefore, the biomass content by the weight method is 60 / 192 = 31.25%.

[0066] FIG. 6 is a cross-sectional view schematically showing an example of a packaging bag produced by heat-sealing the laminated film 12 for packaging materials. The laminated film 12 for packaging materials is formed into a bag by heat-sealing (thermocompression bonding) the outer peripheral ends thereof. Note that the laminated film 12 for packaging materials here is shown as an example composed of two layers, a sealant film 13 and a base film 14. And here, the illustration of the adhesive layer is omitted.

[0067] One packaging laminated film 12 is folded, or two packaging laminated films 12 are overlapped so that the surfaces of the sealant films 13 that form the inner layer of the packaging laminated film 12 face each other, and the outer peripheral ends thereof are heat-sealed. As the 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 packaging laminated films 12A and 12B are overlapped.

[0068] Heating and pressing are performed from the sides of the base films 14A and 14B that form the outer layers of the two packaging laminated films 12A and 12B by a heating roller (not shown) or the like. Then, by heat, the sealant films 13A and 13B are melted, and by pressure, the sealant films 13A and 13B are brought into close contact with each other. Thereby, a seal portion 21 is formed at the outer peripheral ends of the two packaging laminated films 12A and 12B.

[0069] Such a seal portion 21 is formed on three sides of, for example, two rectangular packaging laminated films 12A and 12B, and the remaining one side is used as the filling port for the contents. Then, by further forming a seal portion 21 on one side after the contents are filled from the filling port, a bagged packaging bag (quadruple seal bag 20) is formed.

[0070] Fig. 7 is a perspective view showing a quadruple seal bag 20 as an example of a packaging bag formed by using the packaging laminated film 12 according to the present embodiment. In this way, a flexible packaging bag for filling and packaging frozen foods such as fried fried rice can be formed by the flexible packaging material composed of the sealant film 13 and the base film 14 according to the present embodiment.

[0071] With such a configuration, the usage ratio of petroleum-derived raw materials in the packaging laminated film 12 constituting the packaging bag can be reduced, petroleum resources can be saved, and the amount of petroleum-derived carbon dioxide emissions during the manufacture and disposal of the packaging bag can be suppressed. Especially Since the bag for flexible packaging is easily disposable, according to the laminated film 12 for packaging material according to the present embodiment that reduces the amount of petroleum resources used and suppresses carbon dioxide emissions derived from petroleum, it is possible to provide an environmentally friendly packaging bag. Furthermore, as described above, the processability and physical properties of the laminated film 12 for packaging material according to the present embodiment are not inferior to those derived from petroleum. Therefore, according to the configuration according to the present embodiment, it is possible to provide a packaging bag that includes the bio-low density polyethylene resin 10 in which petroleum resources are saved and the environmental load is reduced, and that has processability and physical properties, particularly durability, that are not inferior to those of a petroleum-based resin.

[0072] Note that an opening cut line may be provided at the end of the packaging bag or the like by a laser or the like. Furthermore, for the packaging bag according to the present embodiment, a one-piece type, a two-piece type spout, a fastener for resealing, or the like can be arbitrarily attached. And, of course, the bio-low density polyethylene resin 10 or the bio-PET resin 19 may be used as these materials.

[0073] In addition to the four-side seal bag 20 illustrated in FIG. 7, various forms of packaging bags according to the present embodiment can be manufactured by heat-sealing by heat-sealing forms such as a side seal type, a two-side seal type, a three-side seal type, an envelope pasting seal type, a palm pasting seal type (pillow seal type), a pleated seal type, a flat bottom seal type, a corner bottom seal type, and others. Furthermore, in the present embodiment, by using the above-described laminated film 12 for packaging material, it is also possible to manufacture a self-supporting packaging bag (standing pouch) or the like, a container including a tube container, a liquid paper container, or the like, a lid material for the container, or a label for the container. Furthermore, the content of the packaging bag according to the present embodiment is not limited to the exemplified food and drink products, and can contain cosmetics, pharmaceuticals, miscellaneous goods, etc., further reducing the usage ratio derived from petroleum and greatly suppressing the carbon dioxide emissions derived from petroleum.

[0074] In addition, in this embodiment, it is preferable that the biomass content is 25% or more throughout the packaging material. Therefore, when a bio-PET film F3 with a biomass content of 20% is used for the base film 14, a configuration in which the sealant film 13 contains, for example, about 35% of the bio-low density polyethylene resin 10 can be considered. On the other hand, when the biomass content of the base film 14 is 0%, the proportion of the bio-low density polyethylene resin 10 in the sealant film 13 is increased to, for example, 70%. In this way, in this embodiment, the biomass content of the entire packaging material is made to be at least 25% or more.

Example

[0075] Hereinafter, examples are shown to explain the present disclosure in more detail and specifically. However, the present disclosure is not limited to the following examples.

[0076] [Example 1] (1) Resin composition 50.0 parts by weight of low density polyethylene (LC525 manufactured by Nippon Polyethylene Co., Ltd.: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 3.5 g / 10 min) and 50.0 parts by weight of bio-mass low density polyethylene (SEB853 manufactured by Braskem S.A.: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 2.7 g / 10 min) were thoroughly kneaded to prepare a resin composition.

[0077] (2) Film Next, using the resin composition prepared in (1), a single-layer film according to this example with a thickness of 30 μm was manufactured using a single-layer upward blown air-cooled inflation coextrusion film making machine. That is, the single-layer film according to Example 1 is a film F1 containing bio-low density polyethylene as shown in FIG. 2. Corona discharge surface treatment (hereinafter referred to as corona treatment) was performed on one surface of the manufactured single-layer film.

[0078] (3) Laminate One side of a biaxially oriented nylon 6 film with a thickness of 15 μm was subjected to corona treatment. Using a normal gravure ink composition on the corona-treated surface, a desired printing pattern was formed by the gravure printing method. After that, a two-component curable polyurethane-based adhesive for lamination was coated on the entire surface including the printing pattern using the gravure roll coating method to a thickness of 4.0 g / m 2 (in the dry state) to form an adhesive layer for lamination. Next, the corona-treated surface of the single-layer film produced in (2) was overlapped with the adhesive layer for lamination facing each other. Then, the two were dry laminated and stacked to produce a laminate.

[0079] (4) Flexible packaging product Next, two sheets of the laminate produced in (3) were prepared, and the surfaces on the side of the film in (2) were overlapped facing each other. Then, the peripheral ends of the outer periphery were heat-sealed in three sides to form a seal portion 21 and a three-side seal type flexible packaging bag having an opening upward was produced. Snack foods were filled and packaged into the three-side seal type flexible packaging bag from the opening. Then, the end of the opening was heat-sealed to form a seal portion 21 to produce a flexible packaging product.

[0080] [Example 2] (1) Resin composition Low-density polyethylene (LC522 manufactured by Japan Polyethylene Corporation: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 4.0 g / 10 min) 30.0 parts by weight, and biomass low-density polyethylene (SPB681 manufactured by Braskem: density d = 0.922 g / cm 3 , melt flow rate (MFR) = 3.8 g / 10 min) 70.0 parts by weight were sufficiently kneaded to prepare a resin composition.

[0081] (2) Film Next, using the resin composition prepared in (1), a single-layer film according to this example with a thickness of 50 μm was produced using a single-layer upward blowing air-cooled inflation coextrusion film manufacturing machine. That is, the single-layer film according to Example 2 is a film F1 containing bio-low density polyethylene as shown in FIG. 2. Corona treatment was performed on one surface of the produced single-layer film.

[0082] (3) Laminate One side of a biaxially stretched PET film with a thickness of 12 μm was subjected to corona treatment. Using a normal gravure ink composition on the corona-treated surface, after forming a desired printing pattern by the gravure printing method, a two-component curable polyurethane-based laminating adhesive was applied to the entire surface including the printing pattern using the gravure roll coating method to a thickness of 4.0 g / m 2 (in the dry state) to form a laminating adhesive layer. Then, the corona-treated surface of the single-layer film produced in (2) was overlapped with the laminating adhesive layer surface facing each other, and then the two were dry laminated and laminated to produce a laminate.

[0083] (4) Flexible packaging product Next, two sheets of the laminate produced in (3) were prepared, and the surfaces on the side of the film in (2) of each were overlapped facing each other. Then, the end portions around the outer periphery were heat-sealed in three sides to form a seal portion 21, and a three-side seal type flexible packaging bag having an opening upward was produced. Snack foods were filled and packaged into the three-side seal type flexible packaging bag through the opening, and then the end portion of the opening was heat-sealed to form a seal portion 21 to produce a flexible packaging product.

[0084] [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 (LC522 manufactured by Nippon Polyethylene Co., Ltd.: density d = 0.923 g / cm 3, 100.0 parts by weight of melt flow rate (MFR) = 4.0 g / 10 min, 0.5 parts by weight of synthetic silica, and 0.05 parts by weight of erucic acid amide were thoroughly kneaded to prepare a resin composition. (b) Resin composition constituting the second layer Biomass low-density polyethylene (SPB681 manufactured by Braskem S.A.: density d = 0.922 g / cm 3 , 100.0 parts by weight of melt flow rate (MFR) = 3.8 g / 10 min was prepared. (c) Resin composition constituting the third layer Low-density polyethylene (LC522 manufactured by Nippon Polyethylene Co., Ltd.: density d = 0.923 g / cm 3 , 100.0 parts by weight of melt flow rate (MFR) = 4.0 g / 10 min, 0.5 parts by weight of synthetic silica, and 0.05 parts by weight of erucic acid amide were thoroughly kneaded to prepare a resin composition.

[0085] (2) Film Next, each resin composition prepared in (1) was used, and these were co-extruded using a three-layer upblown air-cooled inflation co-extrusion film forming machine. The layer made of the resin composition in (a) was 10 μm, the layer made of the resin composition in (b) was 30 μm, and the layer made of the resin composition in (c) was 10 μm, respectively, to form a film. A multilayer laminated film according to this example, which is a co-extruded inflation film with a total thickness of 50 μm, was manufactured. That is, the multilayer laminated film according to Example 3 is a film F2 having a multilayer structure in which the middle layer is made of 10 parts of bio-low-density polyethylene resin as shown in FIG. 3. Corona treatment was applied to the surface of the first layer (a) of the manufactured multilayer laminated film.

[0086] (3) Laminated material One side of a biaxially stretched PET film with a thickness of 12 μm was subjected to corona treatment. Using a normal gravure ink composition on the corona-treated surface, a desired printed pattern was formed by the gravure printing method. Then, a two-component curable polyurethane-based laminating adhesive was applied to the entire surface including the printed pattern using the gravure roll coating method to a thickness of 4.0 g / m 2Coat to be in the [dry state] to form an adhesive layer for lamination. Then, place the corona-treated surface of the layer made of the resin composition of the first layer (a) of the multilayer laminated resin film produced in (2) facing the adhesive layer surface for lamination, and then dry laminate and laminate the two to produce a laminate.

[0087] (4) Flexible packaging product Next, prepare two sheets of the laminate produced in (3), stack them with the surfaces of their respective third layers (c) facing each other, and then triple heat-seal the end portions of the outer periphery thereof to form a seal portion 21 and produce a triple-seal type flexible packaging bag having an opening at the top. Fill and package snack foods into the triple-seal type flexible packaging bag from the opening, and then heat-seal the end portion of the opening to form a seal portion 21 to produce a flexible packaging product.

[0088] [Example 4] (1) Resin composition 30.0 parts by weight of low-density polyethylene (LC520 manufactured by Nippon Polyethylene Co., Ltd.: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 3.6 g / 10 min) and 70.0 parts by weight of biomass low-density polyethylene (SEB853 manufactured by Braskem S.A.: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 2.7 g / 10 min) were thoroughly kneaded to prepare a resin composition.

[0089] (2) Film Next, using the resin composition prepared in (1), a single-layer film according to this example with a thickness of 50 μm was produced using a single-layer upward blown air-cooled inflation coextrusion film making machine. That is, the single-layer film according to Example 4 is a film F1 containing bio-low-density polyethylene as shown in FIG. 2. Corona treatment was performed on one surface of the produced single-layer film.

[0090] (3) Laminate One side of a biaxially oriented PET film with a thickness of 12 μm was subjected to corona treatment, and a two-component curable polyurethane-based laminate adhesive was applied to the corona-treated surface to a thickness of 3.0 g / m 2 (in the dry state) to form an adhesive layer. Then, a biaxially oriented PET film with a thickness of 12 μm that had been corona-treated on both sides was overlapped on the surface of the adhesive layer, and further, in the same manner as above, a two-component curable polyurethane-based laminate adhesive was applied to the surface of the biaxially oriented PET film that had been corona-treated on both sides and laminated above to a thickness of 3.0 g / m 2 (in the dry state) to form an adhesive layer, and a base film 14 was obtained. The surface of the adhesive layer of the base film 14 and the corona-treated surface of the single-layer film produced in (2) were opposed and overlapped to obtain a multilayer laminated film in which the base film 14 of this example was laminated.

[0091] (4) Flexible packaging product Next, two sheets of the laminate produced in (3) were prepared, and the surfaces on the side of the film in (2) were overlapped with each other facing each other. Then, the outer peripheral end portions thereof were heat-sealed on three sides to form a seal portion 21 and a three-side seal type flexible packaging bag having an opening upward was produced. Snack foods were filled and packaged into the three-side seal type flexible packaging bag from its opening, and then the end portion of the opening was heat-sealed to form a seal portion 21 to produce a flexible packaging product.

[0092] [Example 5] (1) Resin composition First, the following resin compositions (a), (b), and (c) were prepared. (a) Resin composition constituting the first layer 100.0 parts by weight of low-density polyethylene (LC522 manufactured by Nippon Polyethylene Co., Ltd.: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 4.0 g / 10 min), 0.5 part by weight of synthetic silica, and 0.05 part by weight of erucic acid amide were sufficiently kneaded to prepare a resin composition. (b) Resin composition constituting the second layer Biomass low-density polyethylene (SPB681 manufactured by Braskem S.A.: 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 (LC522 manufactured by Nippon Polyethylene Co., Ltd.: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 4.0 g / 10 min) 100.0 parts by weight, 0.5 part by weight of synthetic silica, and 0.05 part by weight of erucic acid amide were thoroughly kneaded to prepare a resin composition.

[0093] (2) Film Next, each resin composition prepared in (1) was used, and these were processed using a 3-layer, upward blown air-cooled inflation coextrusion film forming machine. The layer made of the resin composition of (A) was coextruded to a thickness of 10 μm, the layer made of the resin composition of (B) was coextruded to a thickness of 30 μm, and the layer made of the resin composition of (C) was coextruded to a thickness of 10 μm to form a film, thereby manufacturing a multilayer laminated film according to this example, which is a coextruded inflation film with a total thickness of 50 μm for the three layers. That is, the multilayer laminated film according to Example 5 is a film F2 having a multilayer structure in which the middle layer is made of 10 parts of bio-low-density polyethylene resin as shown in Figure 3. Corona treatment was applied to the surface of the first layer (A) of the manufactured multilayer laminated film.

[0094] (3) Laminated material One side of a biaxially stretched PET film with a thickness of 12 μm was subjected to corona treatment, and a two-component curable polyurethane-based laminating adhesive was applied to the corona-treated surface to a thickness of 3.0 g / m 2 (in a dry state) to form an adhesive layer. Then, a biaxially stretched nylon 6 film with a thickness of 15 μm that had been corona-treated on both sides was overlaid on the surface of the adhesive layer. Further, in the same manner as above, a two-component curable polyurethane-based laminating adhesive was applied to the surface of the biaxially stretched nylon 6 film that had been laminated above and corona-treated on both sides to a thickness of 3.0 g / m 2(In the dry state), it was applied to form an adhesive layer, and the base film 14 was obtained. The surface of the adhesive layer of the base film 14 was opposed to the corona-treated surface of the co-extruded multilayer laminated film of (2) and overlapped to obtain a multilayer laminated film in which the base film 14 of this example was laminated.

[0095] (4) Flexible packaging product Next, two sheets of the laminate produced in (3) were prepared, and the surfaces of the respective third layers (c) were opposed to each other and overlapped. Then, the end portions of the outer peripheral periphery thereof were triple heat-sealed to form a seal portion 21, and a triple-sealed type flexible packaging bag having an opening upward was manufactured. The triple-sealed type flexible packaging bag was filled and packaged with fried fried rice rapidly frozen from its opening, and then the end portion of the opening was heat-sealed to form a seal portion 21 to manufacture a flexible packaging product.

[0096] [Example 6] (1) Resin composition 20.0 parts by weight of low-density polyethylene (LC525 manufactured by Japan Polyethylene Corporation: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 3.5 g / 10 min) and 80.0 parts by weight of biomass low-density polyethylene (SEB853 manufactured by Braskem: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 2.7 g / 10 min) were sufficiently kneaded to prepare a resin composition.

[0097] (2) Film Next, each resin composition prepared in (1) was used, and a single-layer film according to this example having a thickness of 30 μm was manufactured using a single-layer upward air-cooled inflation co-extrusion film forming machine. That is, the single-layer film according to Example 6 is a film F1 containing bio-low-density polyethylene as shown in FIG. 2. Corona treatment was performed on one surface of the manufactured single-layer film.

[0098] (3) Laminate One side of a biaxially stretched biomass PET film (bio-PET film F3) with a thickness of 12 μm was subjected to corona treatment. Using a normal gravure ink composition on the corona-treated surface, a desired printing pattern was formed by the gravure printing method. Then, a two-component curable polyurethane-based laminating adhesive was applied to the entire surface including the printing pattern using the gravure roll coating method to a thickness of 4.0 g / m 2 (in the dry state) to form a laminating adhesive layer. Next, the corona-treated surface of the single-layer film produced in (2) was overlapped with the laminating adhesive layer surface facing each other. Then, the two were dry laminated and laminated to produce a laminate.

[0099] (4) Flexible packaging product Next, two sheets of the laminate produced in (3) were prepared, and the surfaces on the side of the film in each (2) were overlapped facing each other. Then, the outer peripheral ends thereof were heat-sealed on three sides to form a seal portion 21 and a three-side seal type flexible packaging bag having an opening upward was produced. Stir-fried fried rice rapidly frozen from the opening was filled and packaged in the three-side seal type flexible packaging bag. Then, the end of the opening was heat-sealed to form a seal portion 21 to produce a flexible packaging product.

[0100] As described in detail above, 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-low-density polyethylene resin 10 obtained by the high-pressure polymerization method. And these films F1 and F2 are used as the sealant film 13 and made into the laminated film 12 for packaging materials laminated with the base film 14, and the packaging bag is made of this laminated film 12 for packaging materials.

Industrial Applicability

[0101] The present disclosure can be applied to films made of polyethylene-based resins, and all products using polyethylene-based resins such as packaging bags and containers composed of these films.

Explanation of Symbols

[0102] 10 Bio-based low-density polyethylene resin 11 Petroleum-derived low-density polyethylene resin 12 Laminated film for packaging materials 13 Sealant film 14 Substrate film 19 Bio-based PET resin 20 Four-sided sealed bag (packaging bag) F1, F2 films (sealant films) F3 Bio-based PET film

Claims

1. A laminated film for packaging materials having a base film, an intermediate layer, and a sealant film in this order, wherein the base film is a polyester resin, the intermediate layer is a barrier resin, the sealant film has an outer layer, a middle layer (excluding linear low density polyethylene), and an inner layer, the resins constituting the outer layer and the inner layer are composed of petroleum-derived low density polyethylene resins, the resin composition constituting the middle layer consists of, as resin components, 10 to 80% by weight of a plant-derived high pressure low density polyethylene resin and 20 to 90% by weight of a petroleum-derived high pressure low density polyethylene resin, The petroleum-derived high-pressure low-density polyethylene resin has a density d of 0.910 to 0.925 g / cm ３ and a melt flow rate (MFR) of 0.5 to 8.0 g / 10 min, The high-pressure low-density polyethylene resin derived from the plant has a density d of 0.910 to 0.925 g / cm ３ and a melt flow rate (MFR) of 0.7 to 3.8 g / 10 min, the sealant film does not contain 0.2% by mass or more of silica, 5.0% by mass or more of titanium oxide, ionomer, and ethylene-methacrylic acid copolymer, and the biomass degree of the entire laminated film for packaging materials is 25% or more. Laminated film for packaging materials.

2. The laminated film for packaging materials according to Claim 1, wherein the plant-derived low density polyethylene resin has a biomass degree of 80 to 100%.

3. A container characterized by using the laminated film for packaging materials according to Claim 1 or 2.

4. A lid material characterized by using the laminated film for packaging materials according to Claim 1 or 2.

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