JP7438650B2 - Composite container with outer box and inner bag - Google Patents

Description

The present invention relates to a composite container including an outer box and an inner bag housed in the outer box.

BACKGROUND ART Conventionally, many bags made of plastic laminated films are filled and sealed with cooked or semi-cooked liquid, viscous, or a mixture of liquid and solid contents on the market. In the bag, the non-sealed portion where the laminated films are not joined constitutes the storage portion in which the contents are stored. Further, a seal portion where the laminated films are joined together seals the housing portion. The contents are, for example, cooked foods such as curry, stew, soup, etc., or semi-cooked foods that are cooked by heating. Heating is performed, for example, by boiling the contents of the bag.

The laminated film constituting the bag is required to have various properties such as heat resistance to withstand heat treatment and impact resistance to withstand the impact received when the bag is dropped. Taking these points into consideration, Patent Document 1, for example, proposes to use a laminated film comprising a polybutylene terephthalate layer, a vapor deposited film, an adhesive layer, and a sealant layer in order from the outer surface to the inner surface. There is. Note that "/" represents the boundary between layers. The adhesive layer is a layer for laminating two films.

Japanese Patent Application Publication No. 2014-15233

In recent years, with the growing call for building a recycling-oriented society, there is a desire to move away from fossil fuels in the materials field as well as in energy. For example, it is desired to reduce the amount of fossil fuel used by using biomass-derived raw materials in the production of laminates.

An object of the present invention is to provide a laminate that can effectively solve such problems.

The present invention includes an outer box containing a paper material, and an inner bag containing a laminate and housed in the outer box, and the laminate includes at least a base layer and a sealant layer in this order. , the base material layer is a composite container containing polyethylene terephthalate having biomass-derived ethylene glycol as a diol unit and fossil fuel-derived terephthalic acid as a dicarboxylic acid unit.

In the composite container according to the present invention, the base layer includes only one stretched film of the polyethylene terephthalate, and the tensile strength of the film is 150 MPa or more and 300 MPa or less in the MD direction, and 150 MPa or more and 300 MPa or less in the TD direction. The following may be sufficient.

In the composite container according to the invention, the sealant layer may contain polypropylene.

In the composite container according to the present invention, the laminate may further include a barrier layer located between the base layer and the sealant layer and containing an inorganic substance.

In the composite container according to the invention, the barrier layer may include metal foil.

In the composite container according to the present invention, the laminate may include an adhesive layer between the base layer and the metal foil and between the metal foil and the sealant layer.

In the composite container according to the invention, the barrier layer may include a vapor deposited layer.

In the composite container according to the present invention, the laminate may include at least the base layer, the vapor deposition layer, the printing layer, and the sealant layer in this order, and the vapor deposition layer may be a transparent vapor deposition film. .

In the composite container according to the present invention, the laminate may include a gas barrier coating film on the surface of the vapor deposited layer.

According to the present invention, it is possible to provide a composite container that has impact resistance and can reduce environmental load.

FIG. 1 is a schematic cross-sectional view showing an example of a laminate according to the present invention. FIG. 1 is a schematic cross-sectional view showing an example of a laminate according to the present invention. FIG. 1 is a schematic front view showing an example of an inner bag according to the present invention. FIG. 1 is a schematic perspective view showing an example of a composite container according to the present invention. FIG. 2 is a diagram showing the evaluation results of the laminates of Examples 1 and 2 and Comparative Examples 1 and 2.

<Laminated body>
The laminate according to the present invention includes at least a base layer and a sealant layer in this order. The laminate may further include a barrier layer located between the base material layer and the sealant layer and containing an inorganic substance. Moreover, the laminate may further include an adhesive layer, a printed layer, other layers, and the like. When the laminate includes two or more adhesive layers or other layers, they may have the same composition or different compositions.

The laminate according to the present invention will be explained with reference to the drawings. Examples of schematic cross-sectional views of the laminate according to the present invention are shown in FIGS. 1 and 2. In the laminate 10 shown in FIG. 1, the barrier layer 13 includes at least a metal foil 131. In the laminate 20 shown in FIG. 2, the barrier layer 23 includes at least a vapor deposited layer 231. The barrier layer may further include a gas barrier coating film.

The laminate 10 shown in FIG. Prepare in order. In the packaging bag including the laminate 10, the sealant layer 12 is located on the inner surface side.

The laminate 20 shown in FIG. 2 includes a base material layer 21, a vapor deposition layer 231 constituting the barrier layer 23, a gas barrier coating film 232 constituting the barrier layer 23, a printed layer 24, and an adhesive layer 25. , and sealant layer 22 in this order. In the packaging bag including the laminate 20, the sealant layer 22 is located on the inner surface side.

Each layer constituting the laminate will be described below.

[Base material layer]
The laminate according to the present invention has only one base material layer that constitutes the outer surface of the laminate. That is, only one plastic film constitutes the base layer. As long as there is only one plastic film in the laminate, the plastic film constituting the base layer may be composed of a single layer or a plurality of layers. When the plastic film constituting the base material layer includes a plurality of layers, the plastic film constituting the base material layer is, for example, a co-extrusion film produced by co-extrusion. By using only one plastic film to constitute the base layer, the cost of the laminate can be reduced.

The base material layer contains polyethylene terephthalate (hereinafter also referred to as PET) derived from biomass. Biomass-derived PET is PET that uses biomass-derived ethylene glycol as a diol unit and fossil fuel-derived terephthalic acid as a dicarboxylic acid unit. The base material layer may further include fossil fuel-derived PET, which has fossil fuel-derived ethylene glycol as a diol unit and fossil fuel-derived terephthalic acid as a dicarboxylic acid unit. It is sufficient if the following biomass degree can be achieved for the base material layer as a whole. In the present invention, since the base material layer contains PET derived from biomass, the amount of PET derived from fossil fuels can be reduced compared to the past, and the environmental load can be reduced.

In the present invention, the "biomass degree" (biomass-derived carbon concentration) of the base material layer is a value obtained by measuring the biomass-derived carbon content by radiocarbon (C14) measurement. Since carbon dioxide in the atmosphere contains C14 at a certain rate (105.5 pMC), the C14 content in plants that grow by taking in atmospheric carbon dioxide, such as corn, is also around 105.5 pMC. It is known. It is also known that fossil fuels contain almost no C14. Therefore, by measuring the proportion of C14 contained in all carbon atoms in PET, the proportion of carbon derived from biomass can be calculated. In the present invention, the biomass-derived carbon content P _bio can be determined as follows, where the C14 content in PET is P _C14 .
P _bio (%) = P _C14 /105.5×100

PET is made by polymerizing ethylene glycol containing 2 carbon atoms and terephthalic acid containing 8 carbon atoms at a molar ratio of 1:1, so if only biomass-derived ethylene glycol is used, the biomass in PET The content of carbon derived from P _bio is 20%. In the present invention, the content of biomass-derived carbon as determined by radiocarbon (C14) measurement is preferably 10% or more and 20% or less, and 10% or more and 19% of the total carbon in biomass-derived PET. It may be the following. If the content of biomass-derived carbon in biomass-derived PET is 10% or more, it is suitable as a carbon offset material. In addition, the content of biomass-derived carbon in fossil fuel-derived PET manufactured using fossil fuel-derived ethylene glycol and fossil fuel-derived dicarboxylic acid is 0%, and the biomass content of fossil fuel-derived PET is 0%. becomes 0%.

In the present invention, the biomass degree of the base material layer is 5% or more, preferably 10% or more, and more preferably 15% or more. If the biomass content of the base material layer is 5% or more, it is possible to reduce the amount of PET derived from fossil fuels and reduce the environmental load compared to the conventional method.

When the base layer is a stretched PET film, the PET film used for the base layer has a tensile strength in the MD direction, preferably 150 MPa or more and 300 MPa or less, more preferably 200 MPa or more and 300 MPa or less, and preferably in the TD direction. is 150 MPa or more and 300 MPa or less, more preferably 150 MPa or more and 300 MPa or less, and the tensile elongation is preferably 50% or more and 250% or less, more preferably 70% or more and 200% or less in the TD direction. It is preferably 50% or more and 250% or less, more preferably 60% or more and 200% or less. Tensile strength and tensile elongation can be measured according to JIS K 7127.

The base layer preferably has a thickness of 5 μm or more and 40 μm or less, more preferably 8 μm or more and 25 μm or less. When the thickness of the base layer is within the above range, it can be easily molded and can be suitably used as a packaging material.

[Sealant layer]
The sealant layer contains one or more resins selected from low density polyethylene, polyethylene such as linear low density polyethylene, and polypropylene. The sealant layer may be a single layer or multilayer. Further, the sealant layer is preferably made of an unstretched film.

The melting point of the material constituting the sealant layer is preferably 150°C or higher, more preferably 160°C or higher. By increasing the melting point of the sealant layer, it becomes possible to retort the packaging bag at a high temperature, thereby shortening the time required for retort treatment. Note that the melting point of the material constituting the sealant layer is lower than the melting point of the resin constituting the base material layer.

Preferably, the sealant layer includes a propylene-ethylene block copolymer. For example, the film constituting the sealant layer is an unstretched film containing a propylene/ethylene block copolymer as a main component. By using the propylene/ethylene block copolymer, the impact resistance of the sealant layer can be increased, and thereby the packaging bag can be prevented from being torn due to impact when dropped. Moreover, the puncture resistance of the laminate can be improved.

Moreover, the sealant layer may further contain a thermoplastic elastomer. By using a thermoplastic elastomer, the impact resistance and puncture resistance of the sealant layer can be further improved.

The thermoplastic elastomer is, for example, a hydrogenated styrene thermoplastic elastomer. The hydrogenated styrenic thermoplastic elastomer has a structure consisting of a polymer block A mainly composed of at least one vinyl aromatic compound and a polymer block B mainly composed of at least one hydrogenated conjugated diene compound. . Further, the thermoplastic elastomer may be an ethylene/α-olefin elastomer. Ethylene/α-olefin elastomer is a low-crystalline or amorphous copolymer elastomer, and is a random copolymer of 50 to 90% by mass of ethylene as the main component and α-olefin as a comonomer. be.

The content of the propylene/ethylene block copolymer in the sealant layer is, for example, 80% by mass or more, preferably 90% by mass or more.

A method for producing a propylene/ethylene block copolymer includes a method of polymerizing raw materials such as propylene and ethylene using a catalyst. As the catalyst, a Ziegler-Natta type catalyst, a metallocene catalyst, or the like can be used.

The thickness of the sealant layer is preferably 30 μm or more, more preferably 40 μm or more. Further, the thickness of the sealant layer is preferably 100 μm or less, more preferably 80 μm or less.

[Barrier layer]
Next, the barrier layer will be explained.

(metal foil)
As the metal foil constituting the barrier layer of the laminate shown in FIG. 1, conventionally known metal foils can be used. Aluminum foil is preferable from the viewpoint of gas barrier properties that block the transmission of oxygen gas, water vapor, etc., and light shielding properties that block the transmission of visible light, ultraviolet rays, etc. The thickness of the metal foil is, for example, 5 μm or more and 15 μm or less.

(vapor deposited layer)
The vapor deposited layer constituting the barrier layer of the laminate shown in FIG. 2 is a layer made of a vapor deposited film that can be formed by a conventionally known method. By providing the vapor deposited layer, it is possible to provide or improve gas barrier properties that prevent permeation of oxygen gas, water vapor, and the like. Note that the barrier layer may include two or more vapor deposited layers. When two or more vapor deposited layers are provided, they may have the same composition or different compositions.

The vapor deposited film is, for example, a transparent vapor deposited film made of an inorganic oxide. Examples of transparent vapor deposited films include silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), and titanium ( A vapor deposited film of an oxide such as Ti), lead (Pb), zirconium (Zr), or yttrium (Y) can be used. In particular, for packaging bags, it is preferable to include a vapor-deposited film of aluminum oxide or silicon oxide.

Inorganic oxides are expressed as, for example, MO _x such as SiO _x , _AlO expressed. The value range of X is 0 to 2 for silicon (Si), 0 to 1.5 for aluminum (Al), 0 to 1 for magnesium (Mg), 0 to 1 for calcium (Ca), Potassium (K) is 0 to 0.5, tin (Sn) is 0 to 2, sodium (Na) is 0 to 0.5, boron (B) is 0 to 1.5, titanium (Ti) can take a value in the range of 0 to 2, lead (Pb) can take a value in the range of 0 to 2, zirconium (Zr) can take a value in the range of 0 to 2, and yttrium (Y) can take a value in the range of 0 to 1.5. In the above, when X=0, it is a completely inorganic substance (pure substance) and is not transparent, and the upper limit of the range of X is a completely oxidized value. Silicon (Si) and aluminum (Al) are preferably used for the packaging material, with silicon (Si) in the range of 1.0 to 2.0 and aluminum (Al) in the range of 0.5 to 1.5. You can use the value of .

Although the thickness of the transparent vapor deposited film varies depending on the type of inorganic oxide used, it is desirable to arbitrarily select the thickness within the range of, for example, 50 Å or more and 2000 Å or less, preferably 100 Å or more and 1000 Å or less. For example, in the case of a vapor deposited film of aluminum oxide or silicon oxide, the film thickness is desirably 50 Å or more and 500 Å or less, more preferably 100 Å or more and 300 Å or less.

A vapor deposited film can be formed on a base material layer or the like using the following formation method. Examples of methods for forming the deposited film include physical vapor deposition methods (PVD methods) such as vacuum evaporation methods, sputtering methods, and ion plating methods, or plasma chemical vapor deposition methods and thermochemical methods. Examples include a chemical vapor deposition method (CVD method) such as a vapor phase growth method and a photochemical vapor deposition method.

(Gas barrier coating film)
If necessary, a gas barrier coating film may be provided on the vapor deposited layer. A gas barrier coating film is a coating film that functions as a layer that suppresses the permeation of oxygen gas, water vapor, and the like. The gas barrier coating film has a general formula R ¹ _n M(OR ² ) _m (wherein, R ¹ and R ² represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, and n represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M.) at least one alkoxide, a polyvinyl alcohol-based resin, and/or It is obtained by a gas barrier composition containing an ethylene/vinyl alcohol copolymer and polycondensed by a sol-gel method in the presence of a sol-gel method catalyst, acid, water, and an organic solvent.

As the alkoxide represented by the above general formula R ¹ _n M(OR ² ) _m , at least one of a partial hydrolyzate of an alkoxide and a condensate of hydrolysis of an alkoxide can be used. In addition, the partial hydrolyzate of the alkoxide described above does not necessarily have to have all the alkoxy groups hydrolyzed, and may be one in which one or more alkoxy groups have been hydrolyzed, or a mixture thereof. As the condensate of alkoxide hydrolysis, a dimer or more of partially hydrolyzed alkoxide, specifically a dimer to hexamer, is used.

In the alkoxide represented by the above general formula R ¹ _n M(OR ² ) _m , silicon, zirconium, titanium, aluminum, and the like can be used as the metal atom represented by M. In this embodiment, preferable metals include silicon, titanium, and the like. Furthermore, in the present invention, alkoxides can be used alone or in combination of two or more alkoxides of different metal atoms in the same solution.

Further, in the alkoxide represented by the above general formula R ¹ _n M (OR ² ) _m , specific examples of the organic group represented by R ¹ include, for example, a methyl group, an ethyl group, an n-propyl group, an i Examples include alkyl groups such as -propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, n-octyl group, and others. Further, in the alkoxide represented by the above general formula R ¹ _n M(OR ² ) _m , specific examples of the organic group represented by R ² include, for example, a methyl group, an ethyl group, an n-propyl group, an i -propyl group, n-butyl group, sec-butyl group, and others. Note that these alkyl groups in the same molecule may be the same or different.

When preparing the above gas barrier composition, for example, a silane coupling agent or the like may be added. As the silane coupling agent, known organoalkoxysilanes containing organic reactive groups can be used. In this embodiment, organoalkoxysilane having an epoxy group is particularly preferably used, and specifically, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β -(3,4-epoxycyclohexyl)ethyltrimethoxysilane and the like can be used. The above silane coupling agents may be used alone or in combination of two or more.

[Printing layer]
The printing layer contains letters, numbers, pictures, figures, symbols, patterns, etc. for decoration, display of contents, display of expiration date, display of manufacturer, seller, etc., and for giving a sense of beauty. This layer forms any desired printed pattern. The printing layer can be provided as necessary, and can be provided, for example, on the base layer or on the gas barrier coating film. The printing layer may be provided on the entire surface of the base material layer, or may be provided on a part of the base material layer. The printing layer can be formed using conventionally known pigments and dyes, and the forming method is not particularly limited.

As shown in FIG. 1, when the barrier layer includes metal foil, the printed layer is provided closer to the base layer than the barrier layer. This makes the printed layer visible from the base layer side. As shown in FIG. 2, when the vapor deposition layer of the barrier layer is a transparent vapor deposition film, the printing layer may be provided closer to the sealant layer than the barrier layer.

The printed layer preferably has a thickness of 0.1 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less, and still more preferably 1 μm or more and 3 μm or less.

(adhesive layer)
When adhering two layers by a dry lamination method, the adhesive layer can be formed by applying an adhesive to the surface of the layer to be laminated and drying it. Examples of adhesives include one-component or two-component curing or non-curing vinyl-based, (meth)acrylic-based, polyamide-based, polyester-based, polyether-based, polyurethane-based, epoxy-based, rubber-based, etc. Solvent-based, water-based, or emulsion-based adhesives can be used. As the two-component curing adhesive, a cured product of a polyol and an isocyanate compound can be used. Coating methods for the above laminating adhesive include, for example, a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a Fontaine method, a transfer roll coating method, and other methods. .

[Other layers]
The laminate according to the present invention may further include a thermoplastic resin layer or the like as another layer. As the thermoplastic resin, polyethylene resins, polypropylene resins, cyclic polyolefin resins, copolymer resins, modified resins, or mixtures (including alloys) of these resins as main components can be used. can.

<Method for manufacturing laminate>
The method for manufacturing the laminate according to the present invention is not particularly limited, and it can be manufactured using a conventionally known method such as a dry lamination method.

The laminate according to the present invention can be provided with surface functions such as chemical functions, electrical functions, magnetic functions, mechanical functions, friction/wear/lubrication functions, optical functions, thermal functions, and biocompatibility. It is also possible to perform secondary processing for this purpose. Examples of secondary processing include embossing, painting, adhesion, printing, metallization (plating, etc.), machining, surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.). Moreover, a molded product can also be manufactured by subjecting the laminate according to the present invention to lamination processing (dry lamination or extrusion lamination), bag making processing, and other post-processing processing.

<Packaging bag (inner bag)>
The packaging bag according to the present invention includes the above-mentioned laminate and can be suitably used for retort sterilization or boil sterilization. For example, the above laminate may be used and folded in half, or two laminates may be prepared, and the surface of the sealant layer of the front laminate and the surface of the sealant layer of the back laminate may be opposed to each other. Then, the peripheral edges are stacked, for example, side seal type, two side seal type, three side seal type, four side seal type, envelope pasting seal type, gasho pasting seal type (pillow seal type), pleated seal type, Various types of packaging bags can be manufactured by heat sealing using a heat sealing method such as a flat bottom seal type or a square bottom seal type. Furthermore, a gusset-type packaging bag can also be manufactured by heat-sealing the folded laminate with the folded laminate inserted between the front laminate and the back laminate. Note that not all of the laminates constituting the packaging bag may be the laminates described above according to the present invention. That is, at least a portion of the laminate forming the packaging bag may be a laminate having a base material layer containing PET derived from biomass, and the other portion of the laminate forming the packaging bag may be formed of PET derived from fossil fuels. It may be a laminate including a base material layer consisting of.

In the above, the heat sealing method can be performed by, for example, a known method such as bar sealing, rotating roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing, or the like.

The packaging bag can have gas barrier properties while exhibiting a high degree of biomass, and furthermore, can have heat resistance that can withstand retort sterilization. For this reason, packaging bags can be used for various products such as food and beverages, fruit juices, juices, drinking water, alcohol, cooked foods, seafood paste products, frozen foods, meat products, boiled foods, rice cakes, liquid soups, and seasonings. It can be suitably used as packaging for food and beverages, liquid detergents, cosmetics, chemical products, etc.

The packaging bag according to the present invention will be explained with reference to the drawings. An example of a schematic front view of a packaging bag according to the present invention is shown in FIG. In the example shown in FIG. 3, the packaging bag is a four-sided sealed bag.
In the packaging bag 50 shown in FIG. 3, the sealant layers of the front film 54 and the back film 55 made of the above-mentioned laminate are arranged to face each other, and three edges other than the upper part of the outer periphery are heat-sealed to seal the periphery. A portion 51 is formed. After filling the contents 58 from the upper opening, for example, after deaerating the contents, the upper end is heat-sealed to form the upper end seal part 52, so that the packaging bag 50 with the contents 58 sealed is sealed. can get. In the above example, the packaging bag 50 is constructed using two films, the front film 54 and the back film 55. However, it is also possible to construct the packaging bag 50 using one film. Good too.

Furthermore, the packaging bag 50 may be provided with an easy-to-open means 59 for opening the packaging bag 50 by tearing the front film 54 and the back film 55. For example, as shown in FIG. 3, the easy-opening means 59 may include a notch 591 formed in the peripheral seal portion 51 and serving as a tearing point. Furthermore, a half-cut line formed by laser processing, a cutter, or the like may be provided as an easy-to-open means 59 in a portion that becomes a path when the packaging bag 50 is torn.

The packaging bag 50 including the laminate may be housed in an outer box containing paper material. That is, the packaging bag 50 including the laminate described above may be used as the inner bag 50 accommodated in the outer box. Hereinafter, an outer box housing the inner bag 50 and a composite container including the outer box and the inner bag will be described.

FIG. 4 is a schematic perspective view showing an example of a composite container 70 according to the present invention. The composite container 70 includes an outer box 60 and an inner bag 50 housed in the outer box 60.

The outer box 60 includes a plurality of face plates 61 that are combined to define a storage space that accommodates the inner bag 50. In the example shown in FIG. 4, the plurality of face plates 61 are combined to form a rectangular parallelepiped-shaped outer box 60.

The face plate 61 includes at least paper material. As the paper material, paper derived from biomass can be used, for example, paper containing plants such as wood as raw materials can be used. Further, as the paper material, paper containing waste paper derived from biomass as a raw material may be used. The biomass degree of the paper material is, for example, 90% or more. Specifically, coated cardboard or the like can be used as the paper material. The basis weight of the paper material is, for example, 200 g/m ² or more and 500 g/m ² or less.

According to the composite container 70 shown in FIG. 4, by accommodating the inner bag 50 in the outer box 60, it is possible to suppress transmission of external impact to the inner bag 50. For example, when the composite container 70 is dropped and an impact is applied to the composite container 70, the outer box 60 can absorb the impact by elastically or inelastically deforming the outer box 60. Therefore, transmission of impact to the inner bag 50 can be suppressed. Therefore, even if the laminate forming the inner bag 50 includes only one plastic film, damage such as bag breakage due to impact can be suppressed from occurring to the inner bag 50. I can do it.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the description of the following examples unless it exceeds the gist thereof.

[Example 1]
As a base material layer, a biaxially stretched PET film (biomass content: 13%, thickness 12 μm) was prepared using fossil fuel-derived terephthalic acid and biomass-derived ethylene glycol (biomass polyester). Subsequently, a printed layer was formed by gravure printing on the surface of the PET film that would be located on the inner side when constructing the packaging bag. Moreover, aluminum foil (manufactured by Toyo Aluminum, thickness 7 μm) was prepared as a barrier layer. Further, as a sealant layer, an unstretched polypropylene film (manufactured by Toray Film Co., Ltd., ZK-99S, thickness 70 μm) was prepared.

Subsequently, a PET film, an aluminum foil, and an unstretched polypropylene film were laminated in this order by a dry lamination method to produce a laminate 10 shown in FIG. 1. The layer structure of this laminate 10 is expressed as follows.
Bio PET/Seal/DL/ALM/DL/CPP
"/" represents the boundary between layers. The leftmost layer is the layer that constitutes the outer surface of the laminate, and the rightmost layer is the layer that constitutes the inner surface of the laminate.
"Bio-PET" means PET derived from biomass. "Mark" means a printed layer. "DL" means adhesive layer containing adhesive. "ALM" means aluminum foil. "CPP" means unstretched polypropylene film.

The adhesive layer between the PET film and the aluminum foil contains a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., base agent: RU-40, curing agent: H-4). The adhesive layer between the aluminum foil and the unstretched polypropylene film contains a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., base material: RU-40, curing agent: H-4).

[Comparative example 1]
As the base material layer, a biaxially stretched PET film (biomass content: 0%, manufactured by Toyobo, E5102, thickness 12 μm) made using fossil fuel-derived terephthalic acid and fossil fuel-derived ethylene glycol was used. A laminate 10 shown in FIG. 1 was produced in the same manner as in Example 1 except for the following. The layer structure of the laminate 10 is expressed as follows.
Fossil PET/Seal/DL/ALM/DL/CPP
"Fossil PET" means PET derived from fossil fuels.

[Example 2]
As a base material layer, a biaxially stretched PET film (biomass content: 13%, thickness 12 μm) was prepared using fossil fuel-derived terephthalic acid and biomass-derived ethylene glycol (biomass polyester). Subsequently, a vapor-deposited layer of aluminum oxide having a thickness of 180 Å was formed on the surface of the PET film that would be located on the inner surface side when constructing the packaging bag. Subsequently, a gas barrier coating film having a thickness of 0.3 μm in a dry state was formed on the vapor deposited layer. Subsequently, a printed layer was formed on the gas barrier coating film by gravure printing. In this way, a PET film was obtained in which a vapor deposition layer, a gas barrier coating film, and a printing layer were formed on the inner surface side in this order.

Further, as a sealant layer, an unstretched polypropylene film (manufactured by Toray Film Co., Ltd., ZK-99S, thickness 70 μm) was prepared.

Subsequently, a PET film and an unstretched polypropylene film were laminated in this order by a dry lamination method to produce a laminate 20 shown in FIG. 2. The layer structure of this laminate 20 is expressed as follows.
Bio-PET/deposited layer/coated film/mark/DL/CPP

The adhesive layer between the PET film and the unstretched polypropylene film contains a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., base material: RU-40, curing agent: H-4).

[Comparative example 2]
As the base material layer, a biaxially stretched PET film (biomass content: 0%, manufactured by Toyobo, E5102, thickness 12 μm) made using fossil fuel-derived terephthalic acid and fossil fuel-derived ethylene glycol was used. A laminate 20 shown in FIG. 2 was produced in the same manner as in Example 2 except for the following. The layer structure of the laminate 20 is expressed as follows.
Fossil PET/deposited layer/coated film/mark/DL/CPP

(Evaluation of gas barrier properties)
The oxygen permeability of the laminates of Examples 1 and 2 and Comparative Examples 1 and 2 was measured using the MOCON method in an environment of 23° C. and 90% RH in accordance with JIS K7126-1. Further, the water vapor permeability of the laminates of Examples 1 and 2 and Comparative Examples 1 and 2 was measured using the MOCON method in an environment of 40° C. and 90% RH in accordance with JIS K7129B. The results are shown in Figure 5.

(Evaluation of seal strength)
Two laminates of Examples 1 and 2 and Comparative Examples 1 and 2 were each prepared, and the inner surfaces of the two laminates were partially heat-sealed. Thereafter, the seal strength between the laminates at a width of 15 mm was measured in accordance with JIS 1707 7.5 in an atmosphere at 23°C. The results are shown in Figure 5.

(Evaluation of heat resistance)
Four-side sealed bags were produced using the laminates of Examples 1 and 2 and Comparative Examples 1 and 2. The contents were filled with water. Subsequently, the four-sided sealed bag was subjected to retort sterilization treatment in which it was heated at 121° C. for 40 minutes. Thereafter, it was confirmed whether whitening was observed on the appearance of the four-sided sealed bag. The results are shown in FIG. In FIG. 5, "good" means that no whitening was visually observed. Moreover, "bad" means that whitening was visually confirmed.

(Evaluation of impact resistance)
Four-sided sealed bags were produced using the laminates of Examples 1 and 2 and Comparative Examples 1 and 2. The contents were filled with water. In addition, an outer box containing paper material was manufactured. Subsequently, the four-sided sealed bag was placed in the outer box to produce a composite container.

After that, the four-sided sealed bag containing water was stored overnight in a 3℃ environment in the outer box, and then the composite container, which was held so that the surface of the outer box was horizontal, was placed at a height of 120 cm. The four-sided sealed bag housed in the outer box was tested to see if it would break by dropping it from above. The results are shown in Figure 5. In FIG. 5, "good" means that the four-sided sealed bag did not break. Furthermore, "bad" means that the four-sided sealed bag has been torn.

10, 20 Laminate 11, 21 Base layer 12, 22 Sealant layer 13, 23 Barrier layer 131 Metal foil 231 Vapor deposited layer 232 Gas barrier coating film 14, 24 Print layer 15, 16, 25 Adhesive layer 50 Inner bag 60 Outside Box 70 Composite container

Claims (6)

An outer box containing paper material,
an inner bag containing a laminate and housed in the outer box,
Only one inner bag is housed in one outer box,
The inner bag is made of the laminate folded in two, or consists of two stacked laminates,
The laminate includes, in this order, a base material layer constituting the outer surface of the laminate, a printing layer, a barrier layer containing an inorganic substance, and a sealant layer,
The base material layer includes polyethylene terephthalate having biomass-derived ethylene glycol as a diol unit and fossil fuel-derived terephthalic acid as a dicarboxylic acid unit,
The base layer includes the stretched polyethylene terephthalate film,
There is one stretched plastic film in the laminate,
The barrier layer includes metal foil,
A composite container, wherein the sealant layer includes a propylene/ethylene block copolymer. The composite container according to claim 1, wherein the tensile strength of the film is 150 MPa or more and 300 MPa or less in the MD direction, and 150 MPa or more and 300 MPa or less in the TD direction. The composite container according to claim 1 or 2, wherein the sealant layer contains polypropylene. The composite container according to any one of claims 1 to 3, wherein the laminate includes an adhesive layer between the base layer and the metal foil and between the metal foil and the sealant layer. . An outer box containing paper material,
an inner bag containing a laminate and housed in the outer box,
Only one inner bag is housed in one outer box,
The inner bag is made of the laminate folded in two, or consists of two stacked laminates,
The laminate includes, in this order, a base material layer constituting the outer surface of the laminate, a barrier layer containing an inorganic substance, a printing layer, and a sealant layer,
The base material layer includes polyethylene terephthalate having biomass-derived ethylene glycol as a diol unit and fossil fuel-derived terephthalic acid as a dicarboxylic acid unit,
The base layer includes the stretched polyethylene terephthalate film,
There is one stretched plastic film in the laminate,
The barrier layer includes a vapor deposited layer,
A composite container, wherein the sealant layer includes a propylene/ethylene block copolymer. The vapor deposition layer is a transparent vapor deposition film,
The laminate includes a gas barrier coating film on the surface of the vapor deposition layer,
The gas barrier coating film has a general formula R ¹ nM(OR ² )m (wherein, R ¹ and R ² represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, and n represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M.) at least one alkoxide, a polyvinyl alcohol-based resin, and/or The composite container according to claim 5, comprising an ethylene/vinyl alcohol copolymer.

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