JP2019127307A - Grain sealing storage bag, grain storage bag, method for preventing grain in grain sealing storage bag or in grain storage bag from insect pest damage, and multilayer film - Google Patents

Abstract

To provide a grain sealing storage bag, which kills or weakens insect pest inside the grain sealing storage bag without requiring usage of an insect repellent and/or an insecticide, and significantly prevents insect pest from intruding from outside of the grain sealing storage bag, and to provide a grain storage bag, a method for preventing grain in the grain sealing storage bag or in the grain storage bag from insect pest damage, and a multilayer film.SOLUTION: A grain sealing storage bag contains at least a multilayer film having a barrier layer, an inner layer and an outer layer. The multilayer film includes the inner layer on one side of the barrier layer, and the outer layer on an opposite side to the inner layer on the barrier layer. An oxygen permeation degree of the multilayer film is 0.1 cc/m/day/atm to 500 cc/m/day/atm. The interlaminar strength between the barrier layer and the outer layer is 0.01 N/15 mm to 2.9 N/15 mm. The multilayer film is constituted to form a bag shape so that the outer layer is positioned outside of the barrier layer, and so that the inner layer is positioned inside of the barrier layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a grain sealed storage bag, a grain storage bag, a method for preventing grains in a grain sealed storage bag or a grain storage bag from pest damage and a multilayer film.

  In the agricultural field, grains such as corn are stored, stored and transported in grain bags such as bags woven with resin fibers. On the other hand, when storing grains in a grain bag, it is difficult to completely remove the pests and their eggs from the grains, and there is a problem that the pests eat and destroy the grains in the grain bag. Then, even if a pest and its egg have adhered to the grain, the use of a sealed bag for grain storage has been studied for the purpose of suppressing the reproduction by suffocating and killing the pest.

  As such a sealed bag for storing grains, for example, in US Patent Application Publication No. 2006/0198861 (Patent Document 1), grains are stored in a multilayer container having a barrier layer having a high oxygen barrier property as an intermediate layer. It describes the system to do. WO 2016/062496 describes a storage bag which has barrier properties and has a layer comprising an insect repellent or an insect repellent.

US Patent Application Publication No. 2006/0198861 International Publication No. 2016/062496

  However, even if such a grain storage system of Patent Document 1 or a storage bag for grains of Patent Document 2 is used, it survives in, for example, Africa, for example, Lager Grain Borer (hereinafter referred to as LGB). There is a risk that the pests belonging to) may be consumed from the outside. The storage bag of Patent Document 2 has a layer containing an insect repellent or insect repellent. However, the effect is not permanent, and it is difficult to fundamentally control the pest breaking.

  The present invention has been made in view of the above problems, and its purpose is to eliminate or weaken the pests inside the sealed grain storage bag without requiring the use of insect repellents and / or insect repellents, And a grain sealed storage bag, a grain sealed storage bag, a grain storage bag, a method for preventing grains in a grain storage bag, a grain storage bag, or a grain storage bag from harmful insect damage from the outside significantly and a multilayer film are provided. is there.

  If the interlayer strength between the barrier layer and the outer layer laminated on the outer surface of the barrier layer is within a predetermined range in the multilayer film constituting the cereal sealed storage bag, the inventors from the outside It has been experimentally found that the penetration of the barrier layer due to the invading pest can be reduced, and the present invention has been completed.

According to a first aspect of the invention,
Including at least a multilayer film having a barrier layer, an inner layer, and an outer layer;
The multilayer film has the inner layer on one side of the barrier layer, and has the outer layer on the opposite side of the barrier layer from the inner layer,
The oxygen permeability of the multilayer film is 0.1 cc / m ² / day / atm or more and 500 cc / m ² / day / atm or less,
The interlayer strength between the barrier layer and the outer layer is 0.01 N / 15 mm or more and 2.9 N / 15 mm or less,
The multilayer film is configured such that the outer layer is positioned outside the barrier layer, and the inner layer is positioned inside the barrier layer to form a bag shape.
A sealed grain storage bag is provided.

The inner layer comprises a sealing layer,
The seal layer may be configured to be located on the innermost side to form a bag shape.

  The barrier layer may comprise at least one barrier material selected from the group consisting of ethylene-vinyl alcohol copolymer, nylon, polyvinylidene chloride, aluminum, aluminum oxide, silica and polyvinyl chloride.

  The outer layer may include at least one selected from the group consisting of polyethylene, ethylene-unsaturated ester copolymer, and polypropylene.

  The outer layer may include at least one selected from the group consisting of high density polyethylene, low density polyethylene and ethylene-α-olefin copolymer.

  The film thickness of the multilayer film may be 40 μm or more and 1000 μm or less.

The grain sealed storage bag has an opening,
The opening may have a zipper tape and may be configured to be sealable.

According to a second aspect of the invention,
An outer bag, and an inner bag accommodated in the outer bag,
The inner bag is the cereal sealed storage bag according to the first aspect,
A grain storage bag is provided.

According to the third aspect of the present invention,
Storing the grains in the grain sealed storage bag according to the first aspect;
Sealing the opening of the sealed grain storage bag.
A method is provided to prevent grains in sealed grain storage bags from pest damage.

According to the fourth aspect of the present invention,
Using the grain sealed storage bag described in the first aspect as an inner bag, and putting the inner bag in an outer bag;
Storing the grain in the grain sealed storage bag;
Sealing the opening of the sealed grain storage bag.
A method is provided for preventing grains in grain storage bags from pest damage.

According to the fifth aspect of the present invention,
Has a barrier layer, an inner layer and an outer layer,
It has the inner layer on one side of the barrier layer, and the outer layer on the side of the barrier layer opposite to the inner layer,
The oxygen permeability is 0.1 cc / m ² / day / atm to 500 cc / m ² / day / atm,
The interlayer strength between the barrier layer and the outer layer is 0.01 N / 15 mm or more and 2.9 N / 15 mm or less.
A multilayer film is provided.

  The barrier layer may comprise at least one barrier material selected from the group consisting of ethylene-vinyl alcohol copolymer, nylon, polyvinylidene chloride, aluminum, aluminum oxide, silica and polyvinyl chloride.

  The outer layer may include at least one selected from the group consisting of polyethylene, ethylene-unsaturated ester copolymer, and polypropylene.

  The film thickness of the multilayer film may be 40 μm or more and 1000 μm or less.

  According to the method and the multilayer film for preventing grains in a grain sealed storage bag, grain storage bag, grain sealed storage bag or grain storage bag of the present invention from pest damage, the insect repellent and / or insect repellent of Without using it, it is possible to kill or weaken the pests inside the sealed grain storage bag and to significantly prevent the infestation of pests from outside the sealed grain storage bag.

It is a figure which shows one example of the cross-sectional structure of the multilayer film in one embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings and the like, but the present invention is not limited to such embodiments.

<Multilayer film>
The multilayer film of one embodiment of the present invention has a barrier layer, an inner layer and an outer layer, an inner layer on one side of the barrier layer, and an outer layer on the side opposite to the inner layer in the barrier layer. That is, in the multilayer film, the outer layer is laminated on one surface of the barrier layer, and the inner layer is laminated on the other surface where the outer layer of the barrier layer is not laminated. First, an example of the structure of the multilayer film according to the present embodiment will be described.

FIG. 1 is a diagram showing an example of a cross-sectional structure of a multilayer film in one embodiment of the present invention. As shown in FIG. 1, the multilayer film 1 according to this example includes a barrier layer 2, an outer layer 3 laminated on one surface (upper surface in FIG. 1) of the barrier layer 2, and the other surface of the barrier layer 2. And a sealing layer 4 which is an inner layer laminated on (the lower surface in FIG. 1). The oxygen permeability of the multilayer film 1 is 0.1 cc / m ² / day / atm or more and 500 cc / m ² / day / atm or less. The interlayer strength between the barrier layer 2 and the outer layer 3 is 0.01 N / 15 mm or more and 2.9 N / 15 mm or less.

  In the example shown in FIG. 1, the outer layer 3 is only one layer, and the inner layer (layer laminated on the lower surface in FIG. 1) is also only one layer of the seal layer 4. However, as long as conditions such as oxygen permeability and interlayer strength are satisfied, a plurality of layers may be laminated on any surface. For example, for the purpose of enhancing the adhesion between the barrier layer 2 and the seal layer 4, one or more inner layers such as an adhesive layer or a bonding layer (binder layer) other than the seal layer 4 It may be laminated between it and the sealing layer 4.

  Hereinafter, characteristics of the multilayer film according to the present embodiment, materials of each layer, and the like will be described in detail.

  The film thickness of the multilayer film is preferably 40 μm to 1000 μm, more preferably 45 μm to 700 μm, more preferably 50 μm to 400 μm, and still more preferably 55 μm to 100 μm.

The oxygen permeability of the multilayer film is 0.1 cc / m ² / day / atm or more and 500 cc / m ² / day / atm or less. This is to improve the sealing performance. By improving the sealing property, when the multilayer film of the present embodiment constitutes a grain sealed storage bag, pests in the bag can be easily killed or weakened. Moreover, grain etc. can be stored well. The oxygen permeability is preferably 0.1 cc / m ² / day / atm to 300 cc / m ² / day / atm, more preferably 0.1 cc / m ² / day / atm to 100 cc / m ² / day. / Atm or less. In this specification, the oxygen permeability is a value measured at 23 ° C. and 60% humidity by the method defined in JIS K7126-1.

  The interlayer strength between the barrier layer and the outer layer is 0.01 N / 15 mm or more and 2.9 N / 15 mm or less. When the interlayer strength is such a value, when the multilayer film of the present embodiment constitutes a grain sealed storage bag, the barrier layer can be significantly prevented from being eaten by insects that can enter from the outside. Thereby, for example, as will be described in detail in the embodiments, the rate of biting (%) by the pests of the bag can be greatly reduced.

  The interlayer strength is preferably 0.1 N / 15 mm or more, more preferably 0.2 N / 15 mm or more, and still more preferably 0.4 N / 15 mm or more. Further, the interlayer strength is preferably 2.5 N / 15 mm or less, more preferably 2.0 N / 15 mm or less, further preferably 1.0 N / 15 mm or less, and still more preferably 0.8 N / 15 mm or less. It is 15 mm or less.

  In this specification, the interlaminar strength between the barrier layer and the outer layer is determined by cutting the film into a strip having a width of 15 mm, peeling off the barrier layer and the outer layer, and using a tensile tester (table type material tester STA-1225 With the chuck of the company), the peeled barrier layer and the outer layer are sandwiched, and the film including the barrier layer and the outer layer is peeled at an angle of 180 ° and a tensile speed of 200 mm / min. is there.

  The interlayer strength between the barrier layer and the outer layer can be appropriately adjusted to the above-mentioned value using any method. For example, the interlaminar strength can be adjusted by the presence or absence of addition of a resin for adjusting the affinity to the material of the outer layer, or the presence or absence of addition of an ethylene-based resin to the material of the barrier layer, etc. is there. Furthermore, the value of the interlayer strength can be adjusted not only by adjustment by addition of such a resin, but also by changing the press bonding conditions such as temperature, pressure and time according to the film forming method of the multilayer film. .

(Barrier layer)
The barrier layer has an oxygen barrier property. By having the barrier layer, when the multilayer film of the present embodiment constitutes a grain sealed storage bag, pests in the bag can be killed or weakened.

The oxygen permeability of the barrier layer is preferably 0.1 cc / m ² / day / atm or more and 500 cc / m ² / day / atm or less, more preferably 0.1 cc / m ² / day / atm or more and 300 cc / m or more ^{It is 2} / day / atm or less, more preferably 0.1 cc / m ² / day / atm or more and 100 cc / m ² / day / atm or less. The thickness of the barrier layer is preferably 1 μm to 40 μm, more preferably 2 μm to 20 μm, still more preferably 3 μm to 10 μm, and still more preferably 4 μm to 7 μm.

  The barrier layer preferably comprises at least one barrier material selected from the group consisting of ethylene-vinyl alcohol copolymer, nylon, polyvinylidene chloride, aluminum oxide, aluminum, silica and polyvinyl chloride, preferably Although composed of these barrier materials, it is not limited to these materials. In addition, these barrier materials may be appropriately modified and used. For example, the barrier layer may be a layer containing an ethylene-vinyl alcohol copolymer and a saponified ethylene-vinyl acetate copolymer. When a resin is used as the barrier material, the melt flow rate (hereinafter also referred to as MFR) at 190 ° C. and a load of 21.18 N is preferably 0.5 g / 10 min or more and 15 g / 10 min or less, more preferably 1 g / 10 min or more and 10 g / min. It is 10 min or less, and more preferably 2 g / 10 min or more and 8 g / 10 min or less. Further, the surface on the outer layer side of the barrier layer may be pretreated by a method known in the art so that the interlayer strength between the barrier layer and the outer layer of the present embodiment is within a predetermined range.

  In this embodiment, when the material of the barrier layer is an ethylene-vinyl alcohol copolymer, it is known that the interlayer strength increases when a partially saponified product of the ethylene-vinyl acetate copolymer is added. When the partially saponified ethylene-vinyl acetate copolymer is added, the content of monomer units derived from ethylene of the partially saponified ethylene-vinyl acetate copolymer is preferably 70% by mass or more and 95% by mass. % Or less, more preferably 75% by mass or more and 85% by mass or less, and the degree of saponification is preferably 20% by mol or more and 100% by mol or less. In this case, the addition amount of the ethylene-vinyl acetate copolymer saponified product is preferably 5% by mass based on the total mass of the ethylene-vinyl alcohol copolymer and the partially saponified ethylene-vinyl acetate copolymer. The content is 30% by mass or less, more preferably 10% by mass to 85% by mass, and still more preferably 20% by mass to 80% by mass.

(Outer layer)
The outer layer is preferably made of a thermoplastic resin. The outer layer is disposed so as to cover the outermost part of the grain sealed storage bag when the multilayer film of the present embodiment constitutes the grain sealed storage bag, and the layer located inside the grain sealed storage bag, such as a barrier layer and the like. Protect the inner layer, as well as the grain.

  More preferably, the outer layer is at least one selected from the group consisting of a polyolefin such as polyethylene or polypropylene, and a copolymer of a polyolefin such as ethylene and an unsaturated ester (for example, an ethylene-unsaturated ester copolymer). It includes species of resins but is not limited to just these resin types. More preferably, the polyethylene is high density polyethylene or (high pressure method) low density polyethylene (hereinafter, also simply referred to as "low density polyethylene"), or an ethylene-α-olefin copolymer.

The high-density polyethylene in this specification, the density of the ethylene homopolymer is preferably at 945 kg / ^{m 3} or more 970 kg / ^{m 3} or less, more preferably less 945 kg / ^{m 3} or more 965 kg / ^{m 3.} The density of this polyethylene is measured according to the method defined in Method A of JIS K7112-1980 after annealing described in JIS K6760-1995.

  The MFR of the high density polyethylene is 0.01 g / 10 min or more and 50 g / 10 min or less, preferably 0.02 g / 10 min or more and 10 g / 10 min or less, more preferably 0.3 g / 10 min or more and 8 g / 10 min or less. . This MFR is a value measured by method A under the conditions of a temperature of 190 ° C. and a load of 21.18 N in the method defined in JIS K 7210-1995.

  Low density polyethylene is an ethylene homopolymer which can be obtained by polymerizing ethylene by a high pressure method. The ethylene homopolymer polymerizes ethylene under conditions of a polymerization pressure of 140 MPa or more and 300 MPa or less and a polymerization temperature of 200 ° C. or more and 300 ° C. or less in the presence of a radical generating agent using, for example, a tank reactor or a tubular reactor. Although it can manufacture by carrying out, it is not limited to this manufacturing method.

In the present specification, low density polyethylene refers to ethylene homopolymer having a density of preferably 920 kg / m ³ or more, more preferably 925 kg / m ³ or more, and still more preferably 928 kg / m ³ or more. Furthermore, the density is preferably less than 945 kg / ^{m 3,} more preferably 935 kg / ^{m 3} or less, more preferably 933kg / ^{m 3} or less. The density of this polyethylene is a value measured according to the method defined in Method A of JIS K7112-1980 after annealing described in JIS K6760-1995.

  The MFR of the low density polyethylene is 0.01 g / 10 min or more and 50 g / 10 min or less, preferably 0.02 g / 10 min or more and 10 g / 10 min or less, more preferably 0.3 min or more and 8 g / 10 min or less. This MFR is a value measured by method A under the conditions of a temperature of 190 ° C. and a load of 21.18 N in the method defined in JIS K 7210-1995. The MFR of the low density polyethylene can be adjusted, for example, by changing the polymerization temperature, the pressure, and the amount of chain transfer agent added during the polymerization of the low density polyethylene.

  The ethylene-α-olefin copolymer is a copolymer containing a monomer unit derived from ethylene and a monomer unit derived from an α-olefin having 3 to 20 carbon atoms. When used in the present embodiment, the content of monomer units of ethylene in the ethylene-α-olefin copolymer is relative to the total mass (100% by mass) of the ethylene-α-olefin copolymer. It is 50 mass% or more. Content of the monomer unit of alpha-olefin of carbon number 3 or more and 20 or less is 50 mass% or less to the total mass (100 mass%) of an ethylene-alpha-olefin copolymer.

  Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-1-pentene, 4- Examples include, but not limited to, methyl-1-hexene and the like. The ethylene-α-olefin copolymer may contain only one kind of these α-olefins, or may contain two or more kinds. Preferably, the alpha-olefin is 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene.

The density of the ethylene -α- olefin copolymer is preferably not 860 kg / ^{m 3} or more 945 kg / ^{m 3} or less, more preferably 880 kg / ^{m 3} or more 945 kg / ^{m 3} or less, more preferably 900 kg / ^{m 3} It is 945 kg / m ³ or less. This density is measured according to the method defined in Method A of JIS K7112-1980 after annealing described in JIS K6760-1995. A person skilled in the art can adjust the density of the ethylene-α-olefin copolymer according to the content of the monomer units of ethylene in the ethylene-α-olefin copolymer.

  Examples of the ethylene-α-olefin copolymer include an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer, an ethylene-4-methyl-1-pentene copolymer, and an ethylene-1-octene copolymer. Polymer, ethylene-1-butene-1-hexene copolymer, ethylene-1-butene-4-methyl-1-pentene copolymer, ethylene-1-butene-1-octene copolymer or ethylene-1-one Examples include, but are not limited to, hexene-1-octene copolymers. Among these, preferably, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-butene-1-hexene copolymer And ethylene-1-butene-1-octene copolymer or ethylene-1-hexene-1-octene copolymer.

  The MFR of the ethylene-α-olefin copolymer is 0.01 g / 10 min or more and 50 g / 10 min or less, preferably 0.02 g / 10 min or more and 10 g / 10 min or less, more preferably 0.3 g / 10 min or more and 8 g. It is 10 min or less. This MFR is a value measured by method A under the conditions of a temperature of 190 ° C. and a load of 21.18 N in the method defined in JIS K 7210-1995. The MFR of the ethylene-α-olefin copolymer can be adjusted, for example, by changing the hydrogen concentration and / or the polymerization temperature at the time of polymerization of the ethylene-α-olefin copolymer. For example, when the hydrogen concentration is increased and / or the polymerization temperature is increased, the MFR of the ethylene-α-olefin copolymer is increased.

  The ethylene-unsaturated ester copolymer is a copolymer containing a monomer unit derived from ethylene and a monomer unit derived from an unsaturated ester. When used in the present embodiment, the content of monomer units of ethylene in the ethylene-unsaturated ester copolymer is relative to the total mass (100% by mass) of the ethylene-unsaturated ester copolymer. It is 60 mass% or more. Content of the monomer unit of unsaturated ester is 40 mass% or less with respect to the total mass (100 mass%) of an ethylene-unsaturated ester copolymer.

  As unsaturated ester, for example, carboxylic acid vinyl ester, unsaturated carboxylic acid alkyl ester or unsaturated carboxylic acid glycidyl ester can be mentioned. Examples of carboxylic acid vinyl esters include vinyl acetate and vinyl propionate. Examples of the unsaturated carboxylic acid alkyl ester include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, and ethyl methacrylate. Examples of the unsaturated carboxylic acid glycidyl ester include glycidyl methacrylate and glycidyl acrylate. The ethylene-unsaturated ester copolymer may contain only one type of these unsaturated esters, or may contain two or more types.

  Examples of the ethylene-unsaturated ester copolymer include ethylene-vinyl acetate copolymer, ethylene-vinyl propionate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene- Butyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-vinyl acetate-methyl methacrylate copolymer, etc. may be mentioned. Not limited to these. When using in the masterbatch in this embodiment, only 1 type of these ethylene- unsaturated ester copolymers may be contained, and 2 or more types may be contained.

  Polypropylene is a propylene homopolymer or a propylene random copolymer. A propylene homopolymer is a polymer obtained by polymerizing a monomer consisting only of propylene. The propylene-based random copolymer is a random copolymer obtained by copolymerizing propylene and / or at least one comonomer selected from ethylene and / or an α-olefin having 4 to 20 carbon atoms. . Content of the monomer unit of ethylene in the propylene random copolymer is less than 50% by mass with respect to the total mass (100% by mass) of the propylene random copolymer.

  Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 2-methyl-1-propene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1- Hexene, 2-ethyl-1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl- 1-butene, 1-heptene, methyl-1-hexene, dimethyl-1-pentene, ethyl-1-pentene, trimethyl-1-butene, methylethyl-1-butene, 1-octene, methyl-1-pentene, ethyl -1-hexene, dimethyl-1-hexene, propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-pentene, propyl-1-pentene, diethyl-1-butene Down, 1-nonene, 1-decene, although 1-undecene or 1-dodecene, without limitation. Preferred is 1-butene, 1-pentene, 1-hexene or 1-octene. More preferably, it is 1-butene or 1-hexene.

  Examples of the propylene-based random copolymer include, but are not limited to, a propylene-ethylene random copolymer, a propylene-α-olefin random copolymer, a propylene-ethylene-α-olefin random copolymer, and the like. . Examples of the propylene-α-olefin random copolymer include propylene-1-butene random copolymer, propylene-1-hexene random copolymer, and the like. Examples of the propylene-ethylene-α-olefin random copolymer include propylene-ethylene-1-butene random copolymer, and propylene-ethylene-1-hexene random copolymer. The propylene-based random copolymer is preferably a propylene-ethylene random copolymer, a propylene-1-butene random copolymer, or a propylene-ethylene-1-butene random copolymer.

  For example, the interlayer strength between the outer layer and the barrier layer can be adjusted to a range suitable for the present invention by adding a resin for adjusting the affinity to the material of the outer layer. In this embodiment, as the resin for adjusting affinity, which is added to the material of the outer layer, maleic anhydride-modified polyolefin, epoxy group-containing polyolefin, ethylene-unsaturated carboxylic acid copolymer, or ethylene-unsaturated carboxylic acid is used. Although an acid salt copolymer etc. are mentioned, it is not limited to these. By adding these resins, the affinity between the outer layer and the barrier layer can be adjusted, and a predetermined interlayer strength can be more effectively obtained. In order to properly adjust the affinity between these layers, it is preferable that there is no adhesive layer between the outer layer and the barrier layer.

  The amount of resin for adjusting the affinity added to the material of the outer layer in order to adjust the interlayer strength to the above-mentioned predetermined value varies depending on the material of the outer layer used and the material of the barrier layer, processing method, etc. . For example, the addition amount is preferably 2% by mass to 85% by mass, more preferably 10% by mass to 85% by mass, based on 100 parts by mass of the total amount of the resin component contained in the outer layer. Preferably they are 20 mass% or more and 80 mass% or less.

  The maleic anhydride-modified polyolefin is preferably a resin obtained by grafting maleic anhydride onto polypropylene or polyethylene. The epoxy group-containing polyolefin is preferably a copolymer containing ethylene and glycidyl methacrylate units, or a resin obtained by grafting glycidyl methacrylate onto polyethylene or polypropylene. An ethylene-unsaturated carboxylic acid copolymer is a copolymer containing ethylene and unsaturated carboxylic acid monomer units. The unsaturated carboxylic acid is preferably acrylic acid or methacrylic acid. As the ethylene-unsaturated carboxylic acid salt copolymer, those obtained by partially neutralizing an ethylene-unsaturated carboxylic acid copolymer with a metal ion such as Na or Zn are widely known.

(Inner layer)
In this specification, the “inner layer” includes a seal layer, an adhesive resin layer, a bonding layer, and the like. Specifically, the “inner layer” means any layer located inside the barrier layer when the multilayer film of the present embodiment constitutes a grain sealed storage bag. Among these, when the multilayer film constitutes the grain sealed storage bag, the seal layer can be preferably configured to be located on the innermost side to form a bag shape. The sealing layer may be formed as a single layer shape, or may be formed in a plurality of laminated shapes.

  The sealing layer is preferably a thermally sealable material and is made of a thermoplastic resin. Similar to the outer layer described above, the seal layer more preferably includes at least one selected from the group consisting of polyethylene, ethylene-unsaturated ester copolymer and polypropylene, but is not limited to only these resin types . More preferably, the polyethylene is high-density polyethylene or low-density polyethylene, or an ethylene-α-olefin copolymer.

  The polypropylene is preferably a low melting propylene based random copolymer having a melting point of 150 ° C. or less or a propylene block copolymer containing an elastomer component. These can be used alone or in combination. As the comonomer, preferably, at least one selected from the group consisting of α-olefins having 3 to 10 carbon atoms, such as ethylene, butene, pentene, hexene, octene, or decene, can be used.

  Also, in order to enhance the adhesion strength between the seal layer (inner layer) and the barrier layer, an adhesive resin may be added to the material of the seal layer (inner layer). The adhesive resin added is the same as the adhesive resin added to the material of the outer layer described above. However, unlike the case of adding to the material of the outer layer, the value of the interlayer strength need not be a predetermined value. Alternatively, instead of adding an adhesive resin to the seal layer (inner layer), an adhesive layer containing these adhesive resins may be further included as an inner layer separately from the seal layer (inner layer).

  If necessary, a lubricant may be contained in the material of the outer layer and / or the seal layer (inner layer). By including a lubricant in the material, the releasability of the layer can be improved.

  Generally as a lubricant, what is marketed as a lubricant can be used. For example, any of hydrocarbon type, fatty acid type, aliphatic amide type and metal soap type may be used, and one or more of them may be used in combination. The amount of the lubricant to be added is not particularly limited, and can be adjusted by those skilled in the art according to the type and content of other materials in each layer and / or the type of processing method.

  Furthermore, you may contain antioxidant in a barrier layer, an outer layer, and / or a sealing layer (inner layer) as needed. By containing the antioxidant, the grain sealed storage bag can be prevented from being oxidized, and the grain can be stored better.

  As the antioxidant, known antioxidants in the art can be appropriately selected and used. Examples include, but are not limited to, amine-based, phenol-based, phosphorus-based, bisphenyl-based and hindered amine-based antioxidants.

  The content of the antioxidant is preferably 0.02 parts by mass or more and 0.5 parts by mass or less, more preferably 0.05 parts by mass or more and 0.3 parts by mass with respect to 100 parts by mass of the resin in each layer. Or less.

  In another embodiment, an essential oil or a repellent agent such as neem oil may be additionally added to at least one of the layers, if necessary.

  The multilayer film of the present embodiment described above is preferably used as an application for constituting a grain sealed storage bag. By using the multilayer film of this embodiment to constitute a sealed grain storage bag, the insect pests inside the sealed grain storage bag are killed or weakened without requiring the use of insect repellents and / or insect repellents. Can do. Furthermore, it is possible to significantly prevent the infestation of pests from the outside of the grain sealed storage bag. Moreover, grain etc. can be stored satisfactorily, and this can greatly suppress the disposal of grain caused by pests. Moreover, cost can be reduced because the use of insect repellent and / or insect repellent can be suppressed.

<Method of manufacturing multilayer film>
The multilayer film of one embodiment of the present invention has a structure in which the respective layers (for example, the outer layer 3, the barrier layer 2, and the seal layer 4 shown in FIG. 1) are finally laminated, and the oxygen permeability and barrier of the multilayer film. As long as the interlayer strength between the layer and the outer layer is within the range of the predetermined value described above, it can be produced by a conventionally known method.

  For example, when the barrier material of the barrier layer is coextruded with other layers at the time of film formation, it is possible to form a film using a coextrusion inflation method or a coextrusion T die casting method. When a film-like barrier material is used, a film-like outer layer and / or a sealing layer (inner layer) and a barrier layer are bonded by a dry laminating method, and an outer layer and a film-like barrier material are extruded and laminated. It is possible to use a method in which a seal layer (inner layer) is bonded or a method in which one of an outer layer or a seal layer (inner layer) is bonded by a dry laminating method and the other is bonded to a barrier layer by extrusion lamination. Further, when a film (layer) formed by coating and curing an emulsified barrier material on a base material is used, or when a film (layer) formed by depositing a barrier material on a base material is used, a barrier is used. It is also possible to use a method of dry laminating the outer layer in the form of a film on the surface on which the material is coated or vapor deposited, or a method of laminating the outer layer by extrusion lamination.

<Grain closed storage bag>
A grain-enclosed storage bag according to one embodiment of the present invention includes at least the multilayer film of the above-described embodiment, wherein the outer layer is located outside the barrier layer, and the inner layer is located inside the barrier layer to form a bag shape. Configured to form. That is, in the multilayer film portion of the grain sealed storage bag, the inner side of the bag is an inner layer (seal layer), and the outer side of the bag is the outer layer with a barrier layer interposed therebetween. In addition, in this specification, “sealed” or “cereal sealed storage bag” does not necessarily mean a completely sealed condition, but suffocates and kills or weakens pests in the bag. Conditions of possible oxygen permeability are contemplated and may have openings as described further below.

  The shape of the grain sealed storage bag may be, for example, a cylindrical shape in the expanded state, but it may be any shape such as a thick plate or a substantially spherical shape. For example, in the case of using the multilayer film of the above-described embodiment that is tubular in the grain sealed storage bag of this embodiment, after cutting out into a cylindrical shape with the inner layer (seal layer) inside, one end of the cylinder It is possible to form a bag shape by heat-sealing the vicinity of the part. Alternatively, when the multilayer film of the above-described embodiment is used as it is, it is possible to form a bag shape by heat-sealing three sides after overlapping the inner layer (seal layer) side of the two multilayer films. It is.

  Grain closed storage bags may have an opening. From the opening, the grain can be accommodated. Examples of cereals include, but are not limited to, rice bran, corn, rice, wheat, buckwheat, buckwheat, beans, acne, or buckwheat and the like. The opening may be provided with a mechanism capable of sealing the opening. For example, it is configured to be sealable by a closure such as a binding band, a zipper tape, a fastener or a string. Alternatively, the opening may also be sealed by heat sealing. The openings are preferably sealed in a sealable manner as closely as possible. This is to suppress the permeation of oxygen, carbon dioxide and water vapor as much as possible, to asphyxiate insects in the grain sealed storage bag reliably, and also to suppress the generation of mold.

<Grain storage bag>
The grain storage bag of one embodiment of the present invention comprises an outer bag and an inner bag accommodated in the outer bag. The inner bag is the grain sealed storage bag of the above-described embodiment. The shape of the outer bag may be, for example, a swelled cylindrical shape as in the case of the sealed grain storage bag, but may be any shape such as a thick plate or a substantially spherical shape. The outer bag may also have an opening. The opening is sealably configured, for example, by a closure such as a tie-band, zipper tape, fastener or string. The outer bag is mainly provided to increase the strength of the bag, for example, when grains are actually accommodated.

  In order to use the grain sealed storage bag of the previous embodiment as an inner bag, the outer bag does not need to contain an insect repellent and / or an insect repellent. Examples of the outer bag include a bag knitted with resin fibers such as polypropylene fibers. In addition, a bag knitted with natural fibers such as hemp or glass fibers may be used.

<Method of preventing grains in sealed grain storage bags from pest damage>
According to one embodiment of the present invention, a method for preventing grains in a sealed grain storage bag from pest damage includes a step of storing grains in the sealed grain storage bag according to the above embodiment, and sealing an opening of the sealed grain storage bag. And a process of The method for sealing the opening of the grain sealed storage bag is as described above. In the present specification, “prevent grain in a bag from damage by pests” means to kill or weaken the existing pests inside the bag and / or to invade pests from outside the bag. It is intended to significantly prevent

  In the present specification, pests include not only LGB but also, for example, Tenebrio obscurus, Tenebrio molitor, Neatus ventralis, Alphitophagus bifasciatus, Myrtle beetle (Alphitobius diaperinus), Myrtle beetle (Alphitobius laevigatus), Myrtle beetle (Tribolium confusum), Myrtle beetle (Tribolium castaneum), Myrium beetle (Tribolium freemanium) Granaria weevil (Sitophilus granarius), P. vulgaris (Rhyzopertha dominica), P. infinacea (Dinoderus minutus), Comenops japonicus (Carpophilus pilosellus), Gimmeidookisui (Carpophilus) dimidiatus), saw palmetto (Oryzaephilus surinamensis), giant spinach (Oryzaephilus mercator), red horned spinach (Cryptolestes pusillus), tobacco beetle (Lasioderma serricorne), ginseng beetle White-necked hornbill (Anthrenus nipponensis), White-necked hornbill (Attagenus unicolor japonicus), White-backed hornbill (Attagenus fasciatus), White-necked hornbill (Dermestes maculatus), Black-backed hornbill (Dermostes maculatus) (Trinodes rufescens), Japanese weevil (Callosobruchus chinensis), Japanese weevil (Callosobruchus maculatus), Japanese bean weevil (Callosobruchus analis), common bean Weevil (Acanthoscelides obtectus), Scarlet hornworm (Gibbium aequinoctiale), Nagaryo hornworm (Ptinus japonicus), Kkunusto (Tenebroides mauritanicus), Hosochibikosuto (Lophocateres pusillus), Prostephanus truncatus, Prostephanus truncat turcicus, Latheticus oryzae, Tribolium destructor, Araecerus fasciculatus, Bruchidius atrolineatus, Callosobruchus rhodesianus, Callosobruchus subinotatus, Caryedon gonagra, Troshimema granarius, Trophyta mechitela citra citra, , Ephestia elutella, moth moth (Corcyra cephalonica), lips ク Para lips (Paralipsa gularis), シ P シ メ イ ガ (Pyralis farinalis), ノ Ag ((Aglossa dimidiata), bacga (S Itotroga cerealella), Hirata Chatate (Liposcelis bostrychophila), Ephestia cautella, Myelois ceratoniae etc. are also included.

  The method of the present embodiment exerts an excellent effect on the invasion of these pests from the outside, and reduces the breakage to the barrier layer of the multilayer film constituting the grain sealed storage bag. Can do.

<Method to prevent grains in the grain storage bag from pest damage>
A method for preventing grains in a grain storage bag according to one embodiment of the present invention from pest damage uses the grain sealed storage bag of the above-described embodiment as an inner bag, and the inner bag is put in an outer bag, and the grain sealed storage Including a step of containing the grain in a bag, and sealing the opening of the grain sealed storage bag. Preferably, after the step of putting the inner bag into the outer bag, the step of accommodating the grain in the sealed grain storage bag is performed, and the opening of the sealed grain storage bag is sealed. Thereafter, the opening of the outer bag may be further sealed. Or when sealing the opening part of a grain sealed storage bag, you may seal the opening part of an outer bag simultaneously. The shape of the outer bag, the opening and material, and the method of sealing the opening of the grain storage bag are the same as described above.

  The present invention will be more specifically described using the following examples and comparative examples, but the present invention is not limited thereto. In Examples and Comparative Examples, "parts" and "%" are based on mass unless otherwise stated.

Example 1
Preparation of Multilayer Film A multilayer film comprising an outer layer, a barrier layer and a seal layer was prepared. As materials for the outer layer and the seal layer, 74.5 parts of ethylene-α-olefin copolymer (Sumikasen-L FS150, manufactured by Sumitomo Chemical, MFR 1.0 g / 10 min, density 922 kg / m ³ ), low density polyethylene 15 parts ( Sumikasen F208-3, manufactured by Sumitomo Chemical Co., Ltd., MFR 1.0 g / 10 min, density 924 kg / m ³ ), 7.5 parts of lubricant masterbatch (Sumikasen-E EMB-10, manufactured by Sumitomo Chemical Co., Ltd.) and antioxidant masterbatch 3 Parts (Sumikasen-E CMB-735, manufactured by Sumitomo Chemical Co., Ltd.) were pellet blended and used. As materials for the barrier layer, 90 parts of ethylene-vinyl alcohol copolymer (EVAL G156B, manufactured by Kuraray, MFR 6.4 g / 10 min) and 10 parts of ethylene-vinyl acetate copolymer saponified product (Mersen H-6051, manufactured by Tosoh Corporation) , Ethylene content 89 mol%, saponification degree 96 mol%, MFR 5.5 g / 10 min) were pellet blended and used. These materials were coextrusion inflation molded at 190 ° C., 2.5 blow up ratio using an annular three layer die. After molding, a three-layered film having a total film thickness of 58 μm and a layer thickness of 26 μm / 6 μm / 26 μm was obtained.

Preparation of first test pouch for evaluation of pest lethality (%) The three-layer film obtained by the above-described method is stacked after the two seal layers of the same film face each other, 3 A 3 × 4 cm first test pouch was made by heat sealing the sides.

Preparation of Second Test Bag for Evaluating the Rate of Eating Out by Pest (%) The three-layer film obtained by the above-mentioned method is overlapped so that the outer layers of two identical films face each other, A 3 × 4 cm second test pouch was prepared by sealing three sides with a stapler. Furthermore, air holes were created at two corners of the bag using a 1 mm needle. That is, the second test sachet is sealed with a stapler in that the stacking order of the three-layer films constituting the sachet is symmetric compared to the first test pouch described above. And the point that the air hole is vacant. The evaluation method will be described in detail later.

Preparation of Third Test Bag for Evaluation of Damaged Number (Individual) of Film During Grain Storage The three-layer film obtained by the above-described method is overlapped so that the seal sides of two identical films face each other. After combining, the 4 × 20 cm third test pouch was produced by heat sealing the three sides. The evaluation method will be described in detail later.

Example 2
Preparation of Multilayer Film A multilayer film comprising an outer layer, a barrier layer and a seal layer was prepared. 80 parts of low density polyethylene (Sumikasen F200, manufactured by Sumitomo Chemical Co., Ltd., MFR 2.0 g / 10 min, density 924 kg / m ³ ) and 20 parts of maleic anhydride modified polyethylene (Admer NF518, manufactured by Mitsui Chemicals) are pellet blended and cyclic Using a single-layer die, coextrusion inflation molding was performed at 190 ° C. and a blow-up ratio of 1.6 to obtain a single-layer film having a thickness of 40 μm. After the outer layer of the film obtained in Example 1 was peeled off, the single-layer film having a thickness of 40 μm was press-pressed thereon at 150 ° C., 3 MPa, 30 sec. After pressure bonding, a three-layered film having a total film thickness of 76 μm and a layer thickness of 40 μm / 6 μm / 26 μm was obtained.

Production of first and second test pouches Using this film, a first test pouch and a second test pouch were produced in the same manner as in Example 1 described above.

Example 3
Preparation of Multilayer Film A multilayer film comprising an outer layer, a barrier layer and a seal layer was prepared. 20 parts of low-density polyethylene (Sumikasen F200, manufactured by Sumitomo Chemical Co., Ltd., MFR 2.0 g / 10 min, density 924 kg / m ³ ) and 80 parts of maleic anhydride-modified polyethylene (Admer NF518, manufactured by Mitsui Chemicals) are pellet-blended and cyclic Using a single-layer die, coextrusion inflation molding was performed at 190 ° C. and a blow-up ratio of 1.6 to obtain a single-layer film having a thickness of 40 μm. After the outermost layer of the film obtained in Example 1 was peeled off, the single-layer film having a thickness of 40 μm was press-pressed thereon at 124 ° C., 10 MPa, 45 sec. After pressure bonding, a three-layered film having a total film thickness of 76 μm and a layer thickness of 40 μm / 6 μm / 26 μm was obtained.

Production of first and second test pouches Using this film, a first test pouch and a second test pouch were produced in the same manner as in Example 1 described above.

Comparative Example 1
Preparation of Multilayer Film The press-pressing conditions of the film were adjusted so that the interlayer strength between the outer layer and the barrier layer was different as compared with the values of the above Examples 1 to 3. Specifically, a three-layer film was produced in the same manner as in Example 3 except that the press bonding condition of the single layer film in Example 3 was changed to 140 ° C., 3 MPa, and 30 seconds.

Production of first, second and third test pouches Further, using this film, the first test pouch, the second test pouch and the third test pouch were produced in the same manner as in Example 1 described above. Test pouches were made.

<Reference example>
Using the grain sealed storage bag (low density polyethylene / adhesive layer / ethylene-vinyl alcohol copolymer / adhesive layer / low density polyethylene, each layer thickness 32/5/5/5/32 μm) manufactured by GrainPro. A first test pouch, a second test pouch and a third test pouch as in Example 1 were made.

  The following measurement and evaluation were performed on the multilayer films, the first test pouch, the second test pouch, and the third test pouch of Examples 1 to 3 and Comparative Example 1 and Reference Example. .

<Measurement of interlaminar strength of multilayer film>
The interlayer strength between the barrier layer and the outer layer of each film was separated by peeling the barrier layer and the outer layer, and using the chuck of a tensile tester (table-type material tester STA-1225, manufactured by Orientec Co., Ltd.) The film containing the barrier layer and the outer layer was peeled off at an angle of 180 ° and a tensile speed of 200 mm / min, and the film was measured by reading the value when the peel strength was stabilized. For the multilayer film (manufactured by GrainPro) of the reference example, the interlayer strength between the adhesive layer and the ethylene-vinyl alcohol copolymer layer was measured.

<Oxygen permeability of multilayer film>
The oxygen permeability of each film was measured at 23 ° C. and 60% humidity by the method defined in JIS K7126-1.

<Evaluation of insect mortality (%) using the first test sachet>
One LGB was placed in each first test pouch produced, and the remaining one side of the overlapping sealing layer (inner layer) was heat sealed to seal the pouch. For each of Examples 1 to 3, Comparative Example 1 and Reference Example, 10 similar bags were produced. LGB was added and stored at 26 ° C. After 1 week, the rate at which LGB was dead was defined as the pest mortality rate (%).

<Evaluation of rate of breakage (%) by pests using second test pouch>
One LGB was placed in each of the prepared second test pouches, and the remaining one side of the overlapping outer layer was sealed with a stapler. The same bag was produced 10 bags about each of Examples 1-3, the comparative example 1, and a reference example. Two weeks after the LGB was added, the rate at which the holes had penetrated the bag was defined as the rate of biting by pests (%). Unlike the first test sachet, by reversing the film stacking order, forming the bag so that the outer layer is placed inside the bag, and making a sealing method that prevents LGB from suffocating and dying The evaluation was made assuming that the bag was breached from the outside.

<Evaluation of the number (number) of scratches on the film during grain storage using the third test sachet>
Each prepared third test pouch was filled with 13 g of corn, the opening of the pouch was tied with a string, and placed in a glass bottle with a diameter of 45 mm and 225 ml. Three similar bags and three glass bottles were produced for each of Example 1, Comparative Example 1 and Reference Example. Five LGBs were released on the outside of each bag and stored at 26 ° C. The number of scratches on the film surface two weeks after putting LGB was counted, and the average value of the three bags was calculated to obtain the number (number) of scratches on the film during grain storage.

Table 1 below shows the measurement and evaluation results of the first, second and third test pouches in Examples 1 to 3, Comparative Example 1 and Reference Example.

  As shown in Table 1, in Examples 1 to 3, since the oxygen permeability was low, the pest mortality rate (%) was 100%. Furthermore, in Examples 1 to 3, compared to Comparative Example 1, the eating rate (%) by pests was significantly reduced. In the commercially available product of GrainPro, which is a reference example, the interlayer strength is considerably high, and the insect biting rate (%) is also high. Furthermore, in Example 1, compared with Comparative Example 1 and the reference example, the number (pieces) of damaged films at grain storage was significantly reduced.

  From these results, if the interlayer strength as in Examples 1 to 3 is a bag using a multilayer film within a predetermined range, even when pests try to enter from the outside, between the outer layer and the barrier layer Since it slips, the pest's jaw does not bite well, the number of film scratches is reduced, and it is thought that it becomes difficult to bite.

  On the other hand, for example, in the case of a commercially available product of GrainPro, which is a reference example, an adhesive layer exists between the outer layer and the barrier layer, so that the pest breaks through both the outer layer and the barrier layer, resulting in a film. It is guessed that a hole will be opened.

  According to the grain sealed storage bag, the method for preventing grains in the grain sealed storage bag from pest damage and the multilayer film according to the present invention, the use of the insect repellent and / or insect repellent is not required due to its use, etc. Pests inside the sealed storage bag can be killed or weakened, and invasion of pests from outside the grain sealed storage bag can be significantly prevented. As a result, the cost of insect repellents and / or insect repellents used to prevent cereals from pest damage is also reduced, and food waste problems caused by pest damage are also overcome. Furthermore, it leads to the simplification of the storage method of grain.

1, multilayer film 2, barrier layer 3, outer layer 4, seal layer

Claims (14)

Including at least a multilayer film having a barrier layer, an inner layer, and an outer layer;
The multilayer film has the inner layer on one side of the barrier layer, and has the outer layer on the opposite side of the barrier layer from the inner layer,
The oxygen permeability of the multilayer film is 0.1 cc / m ² / day / atm or more and 500 cc / m ² / day / atm or less,
The interlayer strength between the barrier layer and the outer layer is 0.01 N / 15 mm or more and 2.9 N / 15 mm or less,
The multilayer film is configured such that the outer layer is positioned outside the barrier layer, and the inner layer is positioned inside the barrier layer to form a bag shape.
Grain sealed storage bag. The inner layer comprises a sealing layer,
Said sealing layer being configured to be located on the innermost side to form a sack shape,
The sealed grain storage bag according to claim 1.   The barrier layer comprises at least one barrier material selected from the group consisting of ethylene-vinyl alcohol copolymer, nylon, polyvinylidene chloride, aluminum, aluminum oxide, silica, and polyvinyl chloride. Grain closed storage bag as described in.   The grain closed storage bag according to any one of claims 1 to 3, wherein the outer layer comprises at least one selected from the group consisting of polyethylene, ethylene-unsaturated ester copolymer and polypropylene.   The said outer layer contains at least 1 selected from the group which consists of a high density polyethylene, a low density polyethylene, and an ethylene-alpha-olefin copolymer, The grain sealed storage bag of any one of Claims 1-3. .   The grain sealed storage bag according to any one of claims 1 to 5, wherein the film thickness of the multilayer film is 40 μm or more and 1000 μm or less. The grain sealed storage bag has an opening,
The opening has a zipper tape and is configured to be sealable.
The grain sealed storage bag according to any one of claims 1 to 6. An outer bag, and an inner bag accommodated in the outer bag,
The inner bag is a cereal sealed storage bag according to any one of claims 1 to 7,
Grain storage bag. The process of accommodating a grain in the grain sealed storage bag according to any one of claims 1 to 7,
Sealing the opening of the sealed grain storage bag.
A method of preventing grains in sealed grain storage bags from pest damage. Using the sealed grain storage bag according to any one of claims 1 to 7 as an inner bag, and putting the inner bag into an outer bag;
Storing the grain in the grain sealed storage bag;
Sealing the opening of the sealed grain storage bag.
A method to prevent grains in a grain storage bag from being damaged by pests. Has a barrier layer, an inner layer and an outer layer,
It has the inner layer on one side of the barrier layer, and the outer layer on the side of the barrier layer opposite to the inner layer,
The oxygen permeability is 0.1 cc / m ² / day / atm to 500 cc / m ² / day / atm,
The interlayer strength between the barrier layer and the outer layer is 0.01 N / 15 mm or more and 2.9 N / 15 mm or less.
Multilayer film.   The barrier layer comprises at least one barrier material selected from the group consisting of ethylene-vinyl alcohol copolymer, nylon, polyvinylidene chloride, aluminum, aluminum oxide, silica, and polyvinyl chloride. Multilayer film.   The multilayer film according to claim 11 or 12, wherein the outer layer comprises at least one selected from the group consisting of polyethylene, ethylene-unsaturated ester copolymer and polypropylene.   The multilayer film according to any one of claims 11 to 13, wherein the multilayer film has a thickness of 40 µm or more and 1000 µm or less.

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