WO2023037895A1

WO2023037895A1 - Laminate film, packaging bag, and packaging body

Info

Publication number: WO2023037895A1
Application number: PCT/JP2022/032101
Authority: WO
Inventors: 正樹佐藤
Original assignee: 凸版印刷株式会社
Priority date: 2021-09-08
Filing date: 2022-08-25
Publication date: 2023-03-16
Also published as: JP2023039112A

Abstract

Provided is a laminate film including a barrier layer and at least one adjacent layer that is adjacent to the barrier layer. The barrier layer has a barrier base material, and a coating layer provided to one surface of the barrier base material so as to face the adjacent layer. The coating layer is formed from an aluminum particle layer composed of aluminum particles, and a resin composition with which openings in the aluminum particle layer are filled. The resin composition includes a polyolefin resin containing an unsaturated fatty acid or an anhydride thereof. The barrier base material and the adjacent layer contain the same resin.

Description

LAMINATED FILM, PACKAGING BAG, AND PACKAGING BODY

The present disclosure relates to laminated films, packaging bags, and packages.

In recent years, there has been a growing demand for the construction of a recycling-oriented society with less environmental impact, and along with this, attempts are being made to recycle and use packaging materials. For example, Patent Literature 1 below proposes a polyethylene laminate for packaging material, which comprises an oriented polyethylene film, a polyethylene layer containing a deposited film, and a heat-sealable polyethylene layer in this order.

JP 2019-166810 A

However, the polyethylene laminate for packaging materials described in Patent Document 1 described above has the following problems.
That is, the polyethylene laminate for packaging materials described in Patent Document 1 is used when a package is formed by sealing a content made of a material containing an acidic or alkaline liquid in a packaging bag obtained using the same. However, there is still room for improvement in terms of suppressing delamination after long-term use of the package.

Therefore, the present disclosure maintains good recyclability and prevents deterioration in adhesion between a barrier layer and an adjacent layer adjacent to the barrier layer even when the material is in contact with a material containing an acidic or alkaline liquid for a long period of time. An object of the present invention is to provide a laminated film, a packaging bag, and a package that can be suppressed.

One aspect of the present disclosure is a laminate film that includes a barrier layer and at least one adjacent layer adjacent to the barrier layer, the barrier layer comprising a barrier substrate and, on one side of the barrier substrate, and a coat layer provided to face the adjacent layer, wherein the coat layer comprises an aluminum particle layer made of aluminum particles and a resin composition filled in gaps between the aluminum particle layers, wherein the resin composition is a laminated film comprising a polyolefin resin comprising an unsaturated fatty acid or an anhydride thereof, wherein the barrier substrate and the adjacent layer comprise the same resin. Here, the adjacent layer adjacent to the barrier layer refers to a layer adjacent to the barrier layer when the adhesive layer is excluded when the laminated film has an adhesive layer.
Moreover, "the same resin" refers to resins that are compatible with each other when melted.

According to the laminated film of the present disclosure, since the barrier base material and the adjacent layers contain the same resin, good recyclability can be maintained. In addition, the laminated film of the present disclosure can suppress a decrease in adhesion between the barrier layer and the adjacent layer even when in contact with a material containing an acidic or alkaline liquid for a long period of time.

The reason why it is possible to suppress the decrease in adhesion between the barrier layer and the adjacent layer even when it is in contact with a material containing an acidic or alkaline liquid for a long period of time is presumed to be as follows. .
That is, when a material containing an acidic or alkaline liquid and a laminate film containing the same resin in the barrier substrate and adjacent layers are in contact for a long period of time, the acidic or alkaline liquid in the material permeates the laminate film, and eventually contact the coating layer. At this time, if the coat layer is composed only of the aluminum particle layer, the acidic or alkaline liquid may come into direct contact with the aluminum particle layer and dissolve the aluminum particle layer. In contrast, in the laminated film of the present disclosure, the coat layer consists of an aluminum particle layer and a resin composition that fills the gaps between the aluminum particle layers, and the resin composition contains an unsaturated fatty acid or an anhydride thereof. By containing the polyolefin resin containing the aluminum particle layer, the resin composition protects the aluminum particle layer from the acidic or alkaline liquid. Therefore, even if the material containing the acidic or alkaline liquid and the laminated film come into contact with each other for a long period of time, the acidic or alkaline liquid in the material permeates the laminated film and the acidic or alkaline liquid comes into contact with the coat layer. , the dissolution of the aluminum particle layer by an acidic or alkaline liquid is suppressed. As a result, deterioration in adhesion between the coat layer and the adjacent layer is suppressed.

In the laminated film, the at least one adjacent layer may be a base layer and a sealant layer provided on both sides of the barrier layer.

In the laminated film, the thickness of the coat layer is preferably 0.1 μm or more.
This laminated film can effectively suppress a decrease in adhesion between the barrier layer and the adjacent layer even if it is in contact with a material containing an acidic or alkaline liquid for a long period of time.

In the laminated film, the thickness of the coat layer is preferably greater than 1 μm.
This laminated film can more effectively suppress the deterioration of adhesion between the barrier layer and the adjacent layer even if it is in contact with a material containing an acidic or alkaline liquid for a long period of time.

Preferably, the laminated film further comprises a hydroxyl group-containing resin layer between the barrier substrate and the coat layer.
In this case, the hydroxyl groups in the hydroxyl-containing resin layer and the aluminum particle layer in the coat layer can be strongly bonded. In addition, it is also possible for the hydroxyl groups in the hydroxyl-containing resin layer and the acid or acid anhydride in the resin composition in the coat layer to bond firmly. Therefore, peeling of the coat layer from the barrier substrate is sufficiently suppressed.

Another aspect of the present disclosure is a packaging bag using the laminated film described above.
According to the packaging bag of the present disclosure, in the laminated film, the barrier base material and the adjacent layers contain the same resin, so good recyclability can be maintained.

In addition, as already mentioned, the laminated film can suppress a decrease in adhesion between the barrier layer and the adjacent layer even when it is in contact with a material containing an acidic or alkaline liquid for a long period of time. Therefore, even if the contents made of a material containing an acidic or alkaline liquid are contained in the packaging bag of the present disclosure and the contents and the laminated film are brought into contact with each other, the barrier layer and the adjacent layer in the laminated film will not be separated from each other. It is possible to suppress the deterioration of the adhesion of.

Yet another aspect of the present disclosure is a package comprising the packaging bag described above and contents accommodated in the packaging bag.
According to the package of the present disclosure, in the laminated film forming the packaging bag, the barrier base material and the adjacent layers contain the same resin, so good recyclability can be maintained.
In addition, as already described, the laminated film can suppress deterioration in adhesion between the barrier layer and the adjacent layer even when it is brought into contact with a material containing an acidic or alkaline liquid for a long period of time. Therefore, according to the package of the present disclosure, even if the content made of a material containing an acidic or alkaline liquid is in contact with the laminated film for a long time, the adhesion between the barrier layer and the adjacent layer in the laminated film is maintained. It is possible to suppress the decrease in sexuality.

According to the present disclosure, it is possible to suppress deterioration in adhesion between the barrier layer and the adjacent layer even when the barrier layer and the adjacent layer are brought into contact with a material containing an acidic or alkaline liquid for a long period of time while maintaining good recyclability. Laminated films, packaging bags and packages are provided.

1 is a cross-sectional view showing one embodiment of a laminated film of the present disclosure; FIG. FIG. 2 is a partial cross-sectional view schematically showing the barrier layer of FIG. 1; 1 is a front view of one embodiment of a package of the present disclosure; FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3; FIG. FIG. 4 is a cross-sectional view showing another embodiment of a laminated film of the present disclosure; FIG. 4 is a cross-sectional view showing another embodiment of a laminated film of the present disclosure; FIG. 4 is a cross-sectional view showing another embodiment of a laminated film of the present disclosure;

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings as the case may be. However, the following embodiments are examples for explaining the present disclosure, and the present disclosure is not limited to the following embodiments. In the following description, the same reference numerals are used for the same elements or elements having the same functions, and duplicate descriptions will be omitted depending on the case. Also, the dimensional ratios in the drawings are not limited to the illustrated ratios.

<Laminated film>
FIG. 1 is a cross-sectional view showing one embodiment of the laminated film of the present disclosure, and FIG. 2 is a partial cross-sectional view schematically showing the barrier layer of FIG. As shown in FIGS. 1 and 2, the laminated film 100 includes a substrate layer 10, an adhesive layer 20, a barrier layer 30, an adhesive layer 40, and a sealant layer 50 in this order. The base material layer 10 is an adjacent layer adjacent to the barrier layer 30 , and the sealant layer 50 is also an adjacent layer adjacent to the barrier layer 30 . The barrier layer 30 has a barrier base material 31 and a coat layer 32 provided on the surface of the barrier base material 31 on the side of the base material layer 10 so as to face the base material layer 10 . The coat layer 32 is composed of an aluminum particle layer 33 made of aluminum particles and a resin composition 34 filled in gaps between the aluminum particle layers 33 . The resin composition 34 contains a polyolefin resin containing unsaturated fatty acids or their anhydrides. Further, the base material layer 10, the barrier base material 31 and the sealant layer 50 contain the same resin (hereinafter sometimes referred to as "resin A").

According to the laminated film 100, the substrate layer 10, the barrier substrate 31, and the sealant layer 50 contain the same resin, so good recyclability can be maintained.

In addition, according to the laminated film 100, it is possible to suppress deterioration in the adhesion between the barrier layer 30 and the base layer 10 even if they are in contact with a material containing an acidic or alkaline liquid for a long period of time.

The laminated film 100 will be described in detail below.

The total content of resin A in the entire laminated film 100 is not particularly limited, but from the viewpoint of improving the recyclability of the laminated film 100, it is preferably 90% by mass or more. The total content of resin A in the entire laminated film 100 is preferably 92% by mass or more, more preferably 95% by mass or more.

However, the total content of the same resin in the entire laminated film 100 is usually less than 100% by mass.

(Base material layer)
The base material layer 10 may contain the same resin as the resin contained in the barrier base material 31 and the sealant layer 50 . Examples of such resins include polyolefin resins and polyester resins.

Examples of polyolefin resins include polyethylene such as low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE); polypropylene; ethylene-vinyl acetate copolymer; Examples include ionomer resins, ethylene-acrylic acid copolymers, ethylene-methyl acrylate copolymers, ethylene-methacrylic acid copolymers, ethylene-propylene copolymers, and the like. These may be used alone or in combination of two or more.

The density of LLDPE is usually 0.910 to 0.940 g/cm ³ and the density of HDPE is usually more than 0.940 g/cm ³ and not more than 0.980 g/cm ³ .

Examples of polyester resins include polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). These may be used alone or in combination of two or more.

The above resin may be a resin obtained using a raw material (monomer) obtained from fossil fuels or a resin obtained using a raw material (monomer) derived from biomass. It is preferably a resin obtained using raw materials. Alternatively, the resin may be a recycled resin. The recycled resin may be mechanically recycled resin or chemically recycled resin.

The thickness of the base material layer 10 is not particularly limited, and may be, for example, 10 μm or more or 20 μm or more. The thickness of the base material layer 10 may be 40 μm or less or 25 μm or less. The thickness of the base material layer 10 is appropriately adjusted according to the application or required properties.

The base material layer 10 may contain at least one additive selected from fillers, antistatic agents, plasticizers, lubricants, antioxidants, etc., if necessary.

The base material layer 10 may be configured by laminating a plurality of materials of the same type. The substrate layer 10 may be composed of either a stretched or unstretched film. At least one stretched film and at least one unstretched film may be laminated. The base layer 10 can improve mechanical strength and dimensional stability by having a film that is arbitrarily stretched in biaxial directions.

(adhesion layer)
The adhesive layer 20 is a layer having a function of bonding the base material layer 10 and the barrier layer 30 together, and the adhesive layer 40 is a layer having a function of bonding the barrier layer 30 and the sealant layer 50 together. By having the adhesive layer 20 in the laminated film 100, the adhesion between the base material layer 10 and the barrier layer 30 can be further enhanced. In addition, since the laminated film 100 has the adhesive layer 40, the adhesion between the barrier layer 30 and the sealant layer 50 can be further enhanced.

The adhesive layers 20, 40 contain, for example, polyolefin resin. Specific examples of such polyolefin resins include high-density polyethylene resin (HDPE), medium-density polyethylene resin (MDPE), LDPE, LLDPE, ethylene-methacrylic acid copolymer (EMAA), ethylene-acrylic acid copolymer Polymer (EAA), ionomer, polypropylene (PP), acid-modified polyethylene, acid-modified polypropylene and the like. When the polyolefin resin contains a resin other than polyethylene resin, it is desirable to keep the content of the resin within 10% by weight of the total polyolefin resin. In order to increase the adhesive strength, the surfaces of the base material layer 10, the barrier layer 30, and the sealant layer 50 may be subjected to corona treatment, ozone treatment, anchor coating, or the like. Although the thickness of the

adhesive layers

20 and 40 is not particularly limited, it is preferably 2 μm or more and 50 μm or less. Sufficient adhesive strength can be obtained by setting the thickness of the

adhesive layers

20 and 40 to 2 μm or more.

The adhesive layers 20 and 40 may be adhesive layers using an adhesive composition containing a dry lamination adhesive or the like instead of a layer containing a polyolefin resin.

Dry laminate adhesives include known adhesives such as urethane-based adhesives, polyester-based adhesives, polyamide-based adhesives, epoxy-based adhesives, and isocyanate-based adhesives. Among these, urethane-based adhesives are preferable from the viewpoint of improving handleability.

In addition, the

adhesive layers

20 and 40 may or may not contain a biomass component, but preferably contain a biomass component from the viewpoint of reducing the environmental load. Specific examples of biomass components include "Dick Dry BM Series" manufactured by DIC Corporation and "ECOAD Series" manufactured by Toyo Ink Co., Ltd. When the

adhesive layers

20 and 40 contain a polyolefin resin, the biomass component may be contained as a polyolefin resin or a component other than the polyolefin resin, and may be contained as a polyolefin resin or a component other than the polyolefin resin. may Alternatively, when the

adhesive layers

20, 40 contain an adhesive, the biomass component may be included as an adhesive or a component other than the adhesive, or may be included as an adhesive and a component other than the adhesive.

The adhesive composition may be an adhesive composition that further contains an organic solvent or an adhesive composition that does not contain an organic solvent. type adhesive composition).

Although the thickness of the

adhesive layers

20 and 40 is not particularly limited, it is possible to prevent the laminate film 100 from becoming too thick while suppressing peeling between the base layer 10 and the barrier layer 30 or between the barrier layer 30 and the sealant layer 50. From the point of view, it is preferably 1 to 5 μm, more preferably 2 to 3 μm.

(barrier layer)
The barrier layer 30 is a layer having barrier properties against gases such as oxygen and water vapor. The barrier base material 31 may contain the same resin as the resin contained in the base material layer 10 and the sealant layer 50 . For example, when the base material layer 10 and the sealant layer 50 contain polyolefin resin, the barrier base material 31 may also contain polyolefin resin. Therefore, for example, when the polyolefin resin contained in the base material layer 10 and the sealant layer 50 is polypropylene, the polyolefin resin contained in the barrier base material 31 may be polypropylene or polyethylene.

When the polyolefin resin contained in the base material layer 10 is biaxially oriented polypropylene, the polyolefin resin contained in the barrier base material 31 is also preferably biaxially oriented polypropylene. In this case, it is possible to prevent at least one of the base material layer 10 and the barrier base material 31 from being curved and causing the base material layer 10 to separate from the barrier layer 30 or the barrier layer 30 to separate from the sealant layer 50 . can.

The thickness of the barrier base material 31 is appropriately adjusted according to the material of the barrier base material 31 and the application of the laminated film 100 .

The aluminum particle layer 33 included in the coat layer 32 is composed of aggregates of aluminum particles, and the aluminum particles are in contact with each other. The aluminum particle layer 33 is obtained by vapor-depositing aluminum on one surface of the barrier base material 31 .

The resin composition 34 filled in the gaps of the aluminum particle layer 33 contains polyolefin resin containing unsaturated fatty acid or its anhydride (hereinafter referred to as "polyolefin copolymer resin"). Here, "containing an unsaturated fatty acid or an anhydride thereof" means containing a structural unit derived from an unsaturated fatty acid or an anhydride thereof.

A polyolefin copolymer resin is a copolymer of monomers containing an olefin such as ethylene and an unsaturated fatty acid or its anhydride. In other words, the polyolefin copolymer resin is a copolymer containing a structural unit derived from an olefin such as ethylene and a structural unit derived from an unsaturated fatty acid or its anhydride.

Examples of unsaturated fatty acids include acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, and crotonic acid.

Examples of unsaturated fatty acid anhydrides include maleic anhydride and itaconic anhydride.

The content of the unsaturated fatty acid or its anhydride in the polyolefin copolymer resin is not particularly limited, but is preferably 0.01 to 5% by mass, more preferably 1 to 4% by mass. preferable. When the content of the unsaturated fatty acid or its anhydride in the polyolefin copolymer resin is 0.01% by mass or more, the polyolefin copolymer resin can be easily rendered water-based (liquefied), resulting in a good aqueous dispersion. can be easily obtained. In addition, since the content of acid (unsaturated fatty acid) or acid anhydride (unsaturated fatty acid anhydride) in the polyolefin copolymer resin is 5% by mass or less, polyolefin The copolymer resin can be stably dispersed in an aqueous medium.

The resin composition 34 may or may not contain at least one of a polyurethane resin and a vinyl-based polymer having a hydroxyl group in its side chain, but preferably contains it. In this case, for example, when the adhesive layer 20 is formed using an adhesive composition containing a polyurethane-based adhesive, the adhesion between the adhesive layer 20 and the coat layer 32 can be further improved.

Although the thickness of the coating layer 32 is not particularly limited, it is preferably 0.1 μm or more, more preferably 1 μm or more, even more preferably 2 μm or more, and particularly 5 μm or more. preferable. When the thickness of the coat layer 32 is 0.1 μm or more, the laminated film 100 can maintain the barrier layer 30 and the base layer 10 or the sealant layer 50 even when it is in contact with a material containing an acidic or alkaline liquid for a long period of time. It is possible to effectively suppress the decrease in adhesion between. Further, when the thickness of the coat layer 32 is more than 1 μm, the adhesion between the barrier layer 30 and the base material layer 10 or the sealant layer 50 does not decrease even when the material containing an acidic or alkaline liquid is in contact for a long period of time. It can be suppressed more effectively.

However, the thickness of the coat layer 32 is preferably 10 μm or less, more preferably 7 μm or less. When the thickness of the coat layer 32 is 10 μm or less, the drying time is further reduced, and the workability is further improved.

The coat layer 32 is formed, for example, by forming an aluminum particle layer 33 on one surface of the barrier base material 31 by a vapor deposition method, applying an aqueous dispersion containing a polyolefin copolymer resin to the aluminum particle layer 33, and drying the aluminum particle layer 33 by heating. can be formed. At this time, the polyolefin copolymer resin is preferably composed of particles. Here, the number average particle diameter of the particles is not particularly limited, but is preferably 1 μm or less, more preferably 0.5 μm or less, even more preferably 0.3 μm or less, Less than 0.1 μm is particularly preferred. By setting the number average particle size of the particles to 1 μm or less, the storage stability of the aqueous dispersion is improved.

However, the number average particle diameter of the particles is preferably 0.05 μm or more from the viewpoint of improving dispersibility. In addition, the aqueous dispersion may or may not contain a non-volatile water-improving aid, from the viewpoint of further suppressing deterioration of the properties of the polyolefin copolymer resin (water resistance of the polyolefin copolymer resin, etc.). Therefore, it is preferable not to contain a non-volatile water conversion aid. Examples of non-volatile water-improving aids include emulsifiers, compounds having a protective colloid action, modified waxes, acid-modified compounds with a high acid value, and water-soluble polymers.

The barrier layer 30 may further include a hydroxyl group-containing resin layer between the barrier base material 31 and the coat layer 32 . In this case, the hydroxyl groups in the hydroxyl-containing resin layer and the aluminum particle layer 33 in the coat layer 32 can be strongly bonded. It also becomes possible for the hydroxyl group in the hydroxyl-containing resin layer and the unsaturated fatty acid or its anhydride in the resin composition 34 in the coat layer 32 to bond firmly. Therefore, peeling of the coat layer 32 from the barrier base material 31 is sufficiently suppressed.

The hydroxyl-containing resin layer contains a hydroxyl-containing resin containing hydroxyl groups. Examples of hydroxyl group-containing resins include ethylene vinyl alcohol copolymer (EVOH) and polyvinyl alcohol (PVA). Among them, EVOH is preferable from the viewpoint of lowering the water vapor permeability.

Although the thickness of the hydroxyl group-containing resin layer is not particularly limited, it is preferably 1 μm or more, more preferably 1.5 μm or more, from the viewpoint of improving film-forming properties and barrier properties. However, the thickness of the hydroxyl group-containing resin layer is preferably 5 μm or less, more preferably 3 μm or less, from the viewpoint of improving adhesion.

(sealant layer)
The sealant layer 50 may contain the same resin as the resin contained in the base material layer 10 and the barrier base material 31 . Examples of such resins include polyolefin resins and polyester resins. As the polyolefin resin and polyester resin, the same polyolefin resin and polyester resin as those used in the base material layer 10 can be used. For example, when the base material layer 10 and the barrier base material 31 contain polyolefin resin, the sealant layer 50 may also contain polyolefin resin. Therefore, for example, when the polyolefin resin contained in the base material layer 10 and the barrier base material 31 is polypropylene, the polyolefin resin contained in the barrier base material 31 may be polypropylene or polyethylene.

However, the sealant layer 50 preferably has a lower melting point than the base material layer 10 and the barrier base material 31 from the viewpoint of improving the heat sealability. For this reason, the polyolefin resin contained in the sealant layer 50 preferably has a lower melting point than the polyolefin resin contained in the base material layer 10 and the barrier base material 31 . For example, when the base material layer 10 and the barrier base material 31 contain polypropylene, the sealant layer 50 preferably contains polyethylene. Here, polyethylene includes LDPE, LLDPE, HDPE, or a mixture of two or more thereof.

The sealant layer 50 can be formed, for example, by bonding a sheet containing polyolefin resin to the adhesive layer 40 .

The thickness of the sealant layer 50 is not particularly limited, and may be, for example, 10 μm or more or 50 μm or more. The thickness of the sealant layer 50 may be 200 μm or less or 100 μm or less.

The laminated film 100 may further contain a printed layer as necessary.

The printing layer uses an ink obtained by adding various pigments, plasticizers, desiccants, stabilizers, etc. to binder resins such as urethane resins, acrylic resins, nitrocellulose resins, or rubber resins. It is a layer formed by Characters, patterns, and the like can be displayed on the printed layer.

The ink may be water-based ink or oil-based ink, but water-based ink is preferred. Since water-based ink uses water or alcohol as a solvent, it can further reduce environmental load. In particular, when the adhesive composition is a non-solvent type adhesive composition, use of a water-based ink can significantly reduce the environmental load. In addition, the ink may or may not be biomass ink, but biomass ink is preferable from the viewpoint of reducing the environmental load. Here, biomass ink refers to ink containing components obtained from biological resources (biomass) such as cotton, pulp, rice bran, vegetable oil, and angiosperm seeds.

As a printing method, for example, known printing methods such as offset printing, gravure printing, flexographic printing, silk screen printing, and inkjet printing can be used. Further, the adhesion of the print layer to the sealant layer 50 can be improved by subjecting the surface of the sealant layer 50 to corona treatment or ozone treatment in advance as a pretreatment.

<Package>
Next, an embodiment of the package of the present disclosure will be described with reference to FIGS. 3 and 4. FIG. 3 is a front view showing one embodiment of the package of the present disclosure, and FIG. 4 is a cross-sectional view taken along line IV-IV of FIG.

As shown in FIGS. 3 and 4, the package 500 includes a packaging bag 400 and a content C housed in the packaging bag 400. As shown in FIGS. The packaging bag 400 is formed using a pair of laminated films 100 . Here, the sealant layer 50 of the laminate film 100 faces inward and the base layer 10 faces outward. The packaging bag 400 is composed of an accommodating portion 503 that accommodates the contents C and an adhesive portion 501 provided around the accommodating portion 503 . The adhesive portion 501 is a portion formed by bonding the sealant layers 50 of the laminated films 100 facing each other, and the accommodation portion 503 is a portion where the sealant layers 50 of the laminated films 100 facing each other are not adhered.

According to the package 500, in the laminated film 100 constituting the packaging bag 400, the base material layer 10, the barrier base material 31 and the sealant layer 50 contain the same resin, so good recyclability can be maintained.

In addition, as already described, the laminated film 100 can suppress deterioration in adhesion between the barrier layer 30 and the substrate layer 10 even when it is in contact with a material containing an acidic or alkaline liquid for a long period of time. . Therefore, according to the package 500, even if the content C made of a material containing an acidic or alkaline liquid is in contact with the laminated film 100 for a long time, the barrier layer 30 and the base layer 10 or A decrease in adhesion to the sealant layer 50 can be suppressed

(Contents)
The content C is not particularly limited and may be appropriately selected according to the use of the packaging bag 400 . However, package 500 is particularly effective when content C is made of a material containing an acidic or alkaline liquid. Examples of such contents C include shampoo, rinse, body soap, detergent, and the like.

(packaging bag)
The pair of laminated films 100 forming the packaging bag 400 does not necessarily have the same layer structure, and may have different layer structures.

The packaging bag 400 may have a half-cut line, and may further have an easy-open processing part at both ends or one end of the half-cut line. Examples of the easy-open processed portion include a group of scars, a V-shaped, U-shaped or I-shaped notch.

At the bonding portion 501 of the packaging bag 400, the sealant layers 50 of the pair of laminated films 100 may be directly bonded to each other by thermal fusion (see FIG. 4), or may be bonded to each other with an adhesive.

(Method for manufacturing package)
Next, a method for manufacturing the package 500 using the laminated film 100 will be described.

First, a pair of laminated films 100 are prepared. Then, the sealant layers 50 of the pair of laminated films 100 are opposed to each other to prepare a laminated body, and the sealant layers 50 are adhered to each other. At this time, a portion of the periphery of the laminate is adhered in a U-shape to form an adhered portion 501, and a non-adhered portion (non-adhered portion) is formed. Thus, a packaging bag having an unbonded portion is obtained.

Next, the content C is filled from the non-bonded portion of the packaging bag having the non-bonded portion. After that, the sealant layers 50 of the laminated film 100 are adhered to each other at the unbonded portions, and the unbonded portions are also formed as bonded portions 501 . In this way, the package 500 comprising the packaging bag 400 and the contents C housed therein can be manufactured.

Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. For example, in the above-described embodiment, in the barrier layer 30, the coat layer 32 is provided on the substrate layer 10 side of the barrier substrate 31. , the coat layer 32 may be provided on the sealant layer 50 side of the barrier base material 31 .

In the above-described embodiment, the laminated film 100 has the base layer 10 and the barrier layer 30 separately. may be In this case, the sealant layer 50 is the adjacent layer. 6, like the laminated film 300 shown in FIG. 5, in the barrier layer 30, the coat layer 32 may be provided on the sealant layer 50 side of the barrier base material 31. As shown in FIG.

Furthermore, in the above-described embodiment, the laminated film 100 has the barrier layer 30 and the sealant layer 50 separately, but as in the laminated film 700 shown in FIG. good. In this case, the substrate layer 10 is the adjacent layer.

In addition, although the

laminated films

100 and 300 are provided with the adhesive layer 20 in the above embodiment, it is also possible to omit the adhesive layer 20 and directly bond the base layer 10 and the barrier layer 30 together. Moreover, although the

laminated films

100 and 300 are provided with the adhesive layer 40 in the above embodiment, it is also possible to omit the adhesive layer 40 and directly bond the barrier layer 30 and the sealant layer 50 together.

In the above-described embodiment, the shape of the packaging bag 400 is not limited to the four-sided bag shown in FIG. The packaging bag 400 may include a mouth plug or a fastener made of synthetic resin that can be repeatedly sealed by fitting a strip-shaped protrusion into a strip-shaped groove.

Furthermore, although the packaging bag 400 is formed using a pair of laminated films 100 in the above embodiment, the laminated film 300 may be used instead of the laminated film 100 . Alternatively, a single

laminated film

100 or 300 may be folded with the sealant layer 50 inside, and the overlapping peripheral edges may be adhered to each other to manufacture a packaging bag.

The contents of the present disclosure will be described in more detail with reference to examples and comparative examples, but the present disclosure is not limited to the following examples.

(Example 1)
A substrate layer (trade name: U-1, manufactured by Mitsui Chemicals Tohcello, Inc.) made of biaxially oriented polypropylene with a thickness of 20 μm was prepared.

On the other hand, VM-OPP (manufactured by MAX Specialty Films, trade name: M15SL6, thickness: 15 μm), which is formed by vapor deposition of an aluminum particle layer (aluminum vapor deposition layer) on a biaxially stretched polypropylene film, is prepared, and the VM is - A resin composition consisting of a polyolefin copolymer resin emulsion containing particles of a polyolefin copolymer resin (copolymer of unsaturated carboxylic acid or its anhydride and ethylene hydrocarbon) on the aluminum particle layer of OPP ( Unitika Ltd., trade name: Arrowbase SD5200, particle number average particle diameter: 1 μm or less) was applied and dried by heating at 90° C. for 1 minute to form a barrier layer having a coating layer with a thickness of 0.5 μm. .

Then, a urethane-based adhesive (manufactured by DIC Corporation, trade name: LX500/KW-75) is applied onto the substrate layer using a dry lamination machine, and the barrier layer obtained as described above is formed. , the coat layer was adhered so as to face the substrate layer to obtain a laminate. Subsequently, a urethane-based adhesive (manufactured by DIC Corporation, trade name: LX500/KW-75) was applied to the barrier base material of the laminate using a dry lamination machine, and LLDPE (Tamapoly) having a thickness of 100 μm was applied. A laminate film was produced by laminating a sealant layer made of LK410L (trade name, manufactured by Co., Ltd.). Thus, a laminated film having a laminated structure as shown in FIG. 1 was produced.

(Comparative example 1)
A laminated film was produced in the same manner as in Example 1, except that VM-OPP was used as the barrier layer.

<Preparation of pouch>
Two laminate films (size: 100 mm x 100 mm) of Example 1 and Comparative Example 1 were prepared, the sealant layers of the two laminate films were opposed to each other to prepare a laminate, and the sealant layers were adhered to each other. At this time, a portion of the peripheral edge of the laminate was adhered to form a U-shape to form an adhered portion, and a non-adhered portion (non-adhered portion) was formed. In this way, a pouch as a packaging bag having an unbonded portion was produced.

Next, body soap (manufactured by Unilever Corporation, trade name: Dove) was filled as a content from the non-bonded portion of the pouch having the non-bonded portion. After that, the sealant layers of the laminated film were adhered to each other in the non-bonded portions, and the non-bonded portions were also used as bonded portions. Thus, a package was produced.

<Evaluation of adhesion between substrate layer and barrier layer>
Two packages obtained as described above were prepared. Then, for one package, three 80 mm x 15 mm test pieces were immediately cut from the package sample, and the three test pieces were subjected to a T-peel tensile test to determine the relationship between the base layer and the barrier layer. The lamination strength (unit: N/15 mm) between the two was measured as the initial lamination strength. At this time, the tensile test was performed at a speed of 300 mm/min. Table 1 shows the results.

On the other hand, the other package was subjected to an accelerated test under conditions of 45 ° C. and normal humidity. A tensile test was performed on the test piece of No. 2 in the same manner as above, and the lamination strength (unit: N/15 mm) between the base layer and the barrier layer was measured as the lamination strength after one month. Table 1 shows the results. Then, from the initial lamination strength and the lamination strength after one month, the reduction rate of the lamination strength was calculated based on the following formula.

Laminate strength reduction rate (%) = 100 × (A0-A1) / A0
(In the above formula, A0 represents the initial lamination strength, and A1 represents the lamination strength after one month.)

From the results shown in Table 1, in the laminated film of Example 1, compared with the laminated film of Comparative Example 1, the rate of decrease in laminate strength from before the accelerated test to one month after the accelerated test was sufficiently suppressed. I knew there was

From the above, according to the laminated film of the present disclosure, the barrier layer and the base layer or the sealant layer can be kept in contact with a material containing an acidic or alkaline liquid for a long period of time while maintaining good recyclability. It was confirmed that the deterioration of the adhesion between the layers can be suppressed.

DESCRIPTION OF SYMBOLS 100,300,600,700... Laminated film 10... Base material layer (adjacent layer) 50... Sealant layer (adjacent layer) 20, 40... Adhesive layer 30... Barrier layer 400... Packaging bag 500... Packaging Body, C... Contents.

Claims

A laminated film comprising a barrier layer and at least one adjacent layer adjacent to the barrier layer,
The barrier layer has a barrier base material and a coat layer provided on one surface of the barrier base material so as to face the adjacent layer,
The coat layer is composed of an aluminum particle layer made of aluminum particles and a resin composition filled in gaps between the aluminum particle layers,
The resin composition comprises a polyolefin resin containing an unsaturated fatty acid or an anhydride thereof,
A laminated film, wherein the barrier base material and the adjacent layer contain the same resin.
The laminated film according to claim 1, wherein said at least one adjacent layer is a base layer and a sealant layer respectively provided on both sides of said barrier layer.
The laminated film according to claim 1 or 2, wherein the coating layer has a thickness of 0.1 µm or more.
The laminated film according to claim 3, wherein the coating layer has a thickness of more than 1 μm.
The laminated film according to any one of claims 1 to 4, further comprising a hydroxyl group-containing resin layer between the barrier base material and the coat layer.
A packaging bag using the laminated film according to any one of claims 1 to 5.
A package comprising the packaging bag according to claim 6 and contents accommodated in the packaging bag.