JP2024028382A - packaging bag - Google Patents

Abstract

The present invention provides a laminate that has excellent interlayer adhesion with a vapor-deposited film and high gas barrier properties. In a first aspect, the packaging bag of the present invention is a packaging bag made of a laminate including at least a base material, a vapor deposited film, and a sealant layer, the base material being at least a polyethylene resin layer. and a surface resin layer, the sealant layer is made of polyethylene resin, the surface resin layer of the base material includes a resin material having a melting point of 150° C. or higher, and the vapor deposited film is formed on the surface of the base material. It is provided on a resin layer, and the base material is characterized in that it has been subjected to a stretching process. [Selection diagram] Figure 1

Description

The present invention relates to packaging bags.

Conventionally, resin films made of polyester resins such as polyethylene terephthalate (hereinafter also referred to as polyester films) have excellent mechanical properties, chemical stability, heat resistance, and transparency, and are inexpensive, so they have been used for the production of packaging bags. used in

Such a polyester film is used as a base material or an intermediate layer, and is usually laminated with a polyethylene film as a sealant layer to form a laminate, which is then molded into a packaging bag.

The above-mentioned packaging bags obtained by molding a laminate of different types of resin films, that is, polyester film and polyethylene film, are difficult to separate into their respective layers, and are collected after use. The current situation is that such packaging bags are not suitable for recycling and are not actively recycled.

In view of this current situation, in order to improve the recyclability of packaging bags, we have applied stretched polyethylene film (stretched polyethylene film) to the base material instead of polyester film, and created new products made of the same material. The production of packaging bags using laminates (monomaterial packaging bags) is being considered.

Japanese Patent Application Publication No. 2005-053223

Recently, the present inventors attempted to form a vapor-deposited film on the surface of a stretched polyethylene film in order to compensate for the gas barrier properties deteriorated by changing the polyester film to a stretched polyethylene film, and found that the difference between the stretched polyethylene film and the deposited film A new problem was discovered in that the adhesion was not sufficient and it was not possible to obtain satisfactory gas barrier properties.

Surprisingly, the present inventors have discovered that by providing a surface resin layer containing a resin material with a melting point of 150° C. or higher on the surface of a stretched polyethylene film, a vapor deposited film formed on the surface resin layer. It has been found that the adhesion of the film is improved, and as a result, the gas barrier properties are significantly improved, and the above-mentioned problems can be solved.

The present invention has been made based on such knowledge, and the problem to be solved is to provide a monomaterial packaging container (packaging bag) that has high recyclability and has high gas barrier properties. It is.

In a first aspect, the packaging bag of the present invention is a packaging bag made of a laminate including at least a base material, a vapor deposited film, and a sealant layer,
The base material includes at least a polyethylene resin layer and a surface resin layer,
The sealant layer is made of polyethylene resin,
The surface resin layer of the base material includes a resin material having a melting point of 150° C. or higher,
The vapor deposited film is provided on the surface resin layer of the base material,
The base material is characterized in that it has been subjected to a stretching process.

In a second aspect, the packaging bag of the present invention is a packaging bag made of a laminate including at least a base material, an intermediate layer, and a sealant layer,
The intermediate layer includes a polyethylene resin layer, a surface resin layer, and a vapor deposited film provided on the surface resin layer,
The base material and the sealant layer are both made of polyethylene resin,
The surface resin layer of the intermediate layer includes a resin material having a melting point of 150° C. or higher,
The polyethylene resin layer and the surface resin layer of the intermediate layer are characterized in that they have been subjected to a stretching process.

In a third aspect, the packaging bag of the present invention is a packaging bag made of a laminate including at least a base material, a vapor deposited film, and a sealant layer,
The sealant layer includes a surface resin layer and a polyethylene resin layer,
The base material is made of polyethylene resin,
The surface resin layer of the sealant layer contains a resin material having a melting point of 150° C. or higher,
The vapor deposition film is provided on a surface resin layer of the sealant layer.

In one embodiment, the surface resin layer includes a resin material having a melting point of 150°C or more and 265°C or less.

In one embodiment, the melting point difference between the polyethylene resin and the resin material included in the surface resin layer and having a melting point of 150°C or higher is 20 to 80°C.

In one embodiment, the resin material of the surface resin layer is made of a polymer having a polar group.

In one embodiment, the resin material of the surface resin layer is ethylene vinyl alcohol copolymer, polyvinyl alcohol, polyester, nylon 6, nylon 6,6, nylon 6-nylon 6,6 copolymer, MXD nylon, and amorphous nylon. One or more resin materials selected from:

In one embodiment, the polyethylene resin layer has a multilayer structure.

In one embodiment, the polyethylene resin layer includes at least one layer containing a compatibilizer.

In one embodiment, the surface resin layer is provided so as to be in contact with the layer containing the compatibilizer of the polyethylene resin layer.

In one embodiment, the laminate further includes a barrier coat layer provided on the deposited film.

In one embodiment, the content of polyethylene resin in the entire laminate is 80% by mass or more.

According to the present invention, it is possible to provide a monomaterial packaging container (packaging bag) having high recyclability and a packaging bag having high gas barrier properties.

FIG. 1 is a front view showing an embodiment of the packaging bag of the present invention. FIG. 1 is a perspective view showing an embodiment of a packaging bag of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of a laminate according to a first aspect, which is included in a packaging bag of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of a laminate according to a first aspect, which is included in a packaging bag of the present invention. FIG. 1 is a schematic cross-sectional view showing one embodiment of a vapor deposition apparatus. FIG. 1 is a schematic cross-sectional view showing one embodiment of a vapor deposition apparatus. It is a schematic sectional view showing one embodiment of the layered product concerning the 2nd aspect with which the packaging bag of the present invention is provided. It is a schematic sectional view showing one embodiment of the layered product concerning the 2nd aspect with which the packaging bag of the present invention is provided. It is a schematic sectional view showing one embodiment of the layered product concerning the 2nd aspect with which the packaging bag of the present invention is provided. It is a schematic sectional view showing one embodiment of the layered product concerning the 3rd aspect with which the packaging bag of the present invention is provided. It is a schematic sectional view showing one embodiment of the layered product concerning the 3rd aspect with which the packaging bag of the present invention is provided.

(packaging bag)
The form of the packaging bag is not particularly limited, and it is preferable to change it appropriately depending on the contents to be filled. For example, it may be a standing pouch type, a side seal type, a two side seal type, a three side seal type, a four side seal type, or an envelope. There are various types of packaging bags, such as pasted seal type, gassho pasted seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, and gusset type.
Moreover, the content to be filled is not particularly limited, and the content may be a liquid, powder, or gel. Moreover, it may be food or non-food.

In one embodiment, the packaging bag 10 of the present invention is a packaging bag in which two laminates are bonded together, as shown in FIG. 1 (hatched areas are heat-sealed areas).

A packaging bag having the form shown in FIG. 1 can be produced by preparing two laminates as described below, stacking the laminates so that the sealant layers face each other, and heat-sealing three sides.

In one embodiment, the packaging container of the present invention is a standing pouch-type packaging bag 20 (hereinafter simply referred to as a standing pouch 20), as shown in FIG. and a bottom (bottom sheet).
The body (side sheet) of the standing pouch 20 is made of a laminate described below.
Further, the bottom portion (bottom sheet) may also be made of a laminate described below. With such a configuration, the gas barrier properties of the standing pouch 20 can be further improved. Moreover, its recyclability can also be improved.

The body (side sheet) of the standing pouch 20 as shown in FIG. 2 can be formed by bag making so that the sealant layer of the laminate becomes the innermost layer.
In another embodiment, two laminates are prepared, stacked one on top of the other with the sealant layers facing each other, and folded into a V-shape from both ends of the stacked laminate, with the sealant layer on the outside. The body (side sheet) of the standing pouch 20 can be formed by inserting the two laminates and heat-sealing them. According to such a manufacturing method, a stand-up pouch having a body with side gussets can be obtained.
Moreover, the bottom part (bottom sheet) of the standing pouch 20 can be formed by inserting a laminate between the bag-formed body parts (side sheets) and heat-sealing them. More specifically, the laminate can be formed by folding the laminate into a V-shape so that the sealant layer is on the outside, inserting it between bag-formed side sheets, and heat-sealing.

Moreover, the packaging bag 10 may be provided with an easy-to-open means 31, as shown in FIG.
Examples of the easy-opening means 31 include, as shown in FIG. 1, a notch 32 that serves as a starting point for tearing, and a half-cut line 33 formed by laser processing, a cutter, etc. as a tearing path.

Moreover, the packaging container may be a stand pouch 20 provided with a pouring nozzle part 41, as shown in FIG.
Furthermore, from the viewpoint of ease of opening, the stand pouch 20 may include a curved portion 42 curved inward, as shown in FIG.
Furthermore, a cutout portion 43 formed by a laser beam or the like may be provided.

Hereinafter, the laminate that constitutes the packaging bag of the present invention will be explained.

(Laminated body according to the first aspect)
In the first aspect, the laminate 50 includes a base material 51, a deposited film 52, and a sealant layer 53, as shown in FIG. 3, and the base material 51 includes a polyethylene resin layer 54 and a surface resin layer. 55. The deposited film 52 is provided adjacent to the surface resin layer 55 of the base material 51 .
The polyethylene resin layer and the sealant layer of the base material of the laminate contain the same resin, that is, polyethylene resin, and the laminate having such a structure can be used as a laminate for producing a monomaterial packaging container. It can be suitably used as a body.

The content of polyethylene resin relative to the total solid content contained in the laminate constituting the packaging bag is preferably 80% by mass or more, more preferably 90% by mass or more. This makes it possible to obtain a laminate that can be suitably used for producing monomaterial packaging containers (packaging bags).

In one embodiment, the base material 51 can further include an adhesive resin layer 56 between the polyethylene resin layer 54 and the surface resin layer 55, as shown in FIG.

Furthermore, in one embodiment, the laminate 50 includes a barrier coat layer between the deposited film 52 and the sealant layer 53 (not shown).

Additionally, in one embodiment, laminate 50 includes an adhesive layer between any layers (not shown).

Each layer included in the laminate according to the first aspect will be described below.

(Base material)
The base material includes at least a polyethylene resin layer and a surface resin layer. In one embodiment, the base material includes an adhesive resin layer between the polyethylene resin layer and the surface resin layer.

The ratio of the thickness of the surface resin layer to the total thickness of the base material is preferably 2% or more and 20% or less, more preferably 4% or more and 15% or less.
By setting the ratio of the thickness of the surface resin layer to the total thickness of the base material to be 2% or more, the adhesion of the deposited film can be further improved, and the gas barrier properties can be further improved.
Further, by setting the ratio of the thickness of the surface resin layer to the total thickness of the base material to be 20% or less, a laminate that can be suitably used for producing a monomaterial packaging container can be obtained. Furthermore, the film formability and processing suitability of the base material can be further improved.

(Polyethylene resin layer)
The polyethylene resin layer is made of polyethylene resin.
As polyethylene resins, high-density polyethylene resins (HDPE), medium-density polyethylene resins (MDPE), low-density polyethylene resins (LDPE), linear low-density polyethylene resins (LLDPE), and very low-density polyethylene resins (VLDPE) are used. can do.
Moreover, a copolymer of ethylene and other monomers can also be used as the polyethylene resin.
Furthermore, as the polyethylene resin, a biomass-derived polyethylene resin or a mechanically recycled or chemically recycled polyethylene resin can also be used.

Here, as the high-density polyethylene resin, a polyethylene resin with a density of 0.945 g/cm ³ or more can be used, and as the medium-density polyethylene resin, a polyethylene resin with a density of 0.925 g/cm ³ or more can be used. As the low density polyethylene resin, a polyethylene resin having a density of 0.900 ^{g/cm 3 or more and less than 0.925 g/cm 3 can be} used, and a linear low density polyethylene resin can be used. As the polyethylene resin, polyethylene resin with a density of 0.900 g/cm ³ or more and less than 0.925 g/cm ³ can be used, and as the ultra-low density polyethylene resin, polyethylene resin with a density of less than 0.900 g/cm ³ can be used. Resin can be used.

The content of polyethylene resin in the polyethylene resin layer is preferably 70% by mass or more, more preferably 80% by mass or more. This allows the laminate to be used more favorably in the production of monomaterial packaging containers.

In one embodiment, the polyethylene resin layer may include at least one layer containing a compatibilizer.
Since the polyethylene resin layer contains a compatibilizer, when a packaging container made using a laminate is heated and melted and recycled, the resin material with a melting point of 150°C or higher contained in the surface resin layer and the polyethylene resin layer The polyethylene resin contained in the polyethylene resin is uniformly mixed with the polyethylene resin, and the deterioration of its physical properties can be effectively prevented. Further, it is possible to effectively prevent the transparency from decreasing.
Note that when the polyethylene resin layer has a multilayer structure, the compatibilizing agent is preferably contained in a layer that is in contact with the surface resin layer of the polyethylene resin layer. The above effects can be further improved by containing a compatibilizer in a layer of the polyethylene resin layer that is in contact with the surface resin layer.

Conventionally known compatibilizers can be appropriately selected and used, but from the viewpoint of recyclability, unsaturated carboxylic acid-modified polyolefin resins are preferred, and maleic anhydride-modified polyethylene resins are particularly preferred.

The content of the compatibilizer in the layer containing the compatibilizer is preferably 5% by mass or more and 30% by mass or less.
By setting the content of the compatibilizer in the polyethylene resin layer to 5% by mass or more, the above effects can be further improved.
By controlling the content of the compatibilizer in the polyethylene resin layer to 30% by mass or less, the strength and heat resistance of the base material can be improved.

As long as the characteristics of the present invention are not impaired, the polyethylene resin layer may contain resin materials other than polyethylene resin, such as polyolefin resins such as polypropylene resins, (meth)acrylic resins, vinyl resins, cellulose resins, and polyamide resins. Examples include resins, polyester resins, and ionomer resins.
Note that, from the viewpoint of its recyclability, it is particularly preferable that the polyethylene resin layer does not contain any resin other than polyethylene resin.

In addition, the polyethylene resin layer may contain additives within a range that does not impair the characteristics of the present invention, such as a crosslinking agent, an antioxidant, an anti-blocking agent, a slip agent, an ultraviolet absorber, and a light stabilizer. agents, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.

The polyethylene resin layer included in the base material may have a single layer structure or a multilayer structure.

In a polyethylene resin layer having a multilayer structure, the densities of the polyethylene resins constituting each layer may be different, that is, the polyethylene resin layer may be provided with a density gradient.
By providing a density gradient in the polyethylene resin layer, its strength, heat resistance and stretching suitability are significantly improved.

In a polyethylene resin layer provided with a density gradient, if the density difference between each layer is large, there is a risk that delamination (delamination) at the interface will occur. Therefore, the density difference between each layer is preferably 0.04 g/cm ³ or less, more preferably 0.02 g/cm ³ or less.

Below, embodiments of a polyethylene resin layer provided with a density gradient will be illustrated. Note that the configuration of the polyethylene resin layer is not limited to these.

In one embodiment, the polyethylene resin layer provided with a density gradient consists of three layers: a layer containing high-density polyethylene resin, a layer containing medium-density polyethylene resin, and a layer containing high-density polyethylene resin.
By forming the polyethylene resin layer into a three-layer structure with a density gradient as described above, strength, heat resistance, and stretching suitability are significantly improved. Further, it is possible to effectively prevent curling in the base material.

In one embodiment, the polyethylene resin layer provided with a density gradient includes a layer containing high-density polyethylene, a layer containing medium-density polyethylene resin, and at least one of a low-density polyethylene resin and a linear low-density polyethylene resin. It consists of five layers: a layer containing a medium-density polyethylene resin, and a layer containing a high-density polyethylene resin.
By forming the polyethylene resin layer into a five-layer structure with a density gradient as described above, strength, heat resistance, and stretching suitability are significantly improved. Further, it is possible to effectively prevent curling in the base material.
A polyethylene resin layer having such a structure can be stably produced by the following inflation method.
Specifically, from the outside, a high-density polyethylene resin, a medium-density polyethylene resin, and at least one of a low-density polyethylene resin and a linear low-density polyethylene resin are coextruded into a tube shape,
Next, layers containing at least one of the low-density polyethylene resin and the linear low-density polyethylene resin can be produced by pressing them together using a rubber roll or the like.
By manufacturing using such a method, the number of defective products during manufacturing can be significantly reduced, and ultimately production efficiency can be improved.

In one embodiment, the density-graded polyethylene resin layer includes a layer comprising a high-density polyethylene resin, a layer comprising a blend resin of a high-density polyethylene resin and a medium-density polyethylene resin, and a layer comprising a blend resin of a low-density polyethylene resin and a linear It consists of seven layers: a layer containing at least one of low-density polyethylene resins, a layer containing a blend resin of high-density polyethylene resin and medium-density polyethylene resin, and a layer containing high-density polyethylene resin.
By forming the polyethylene resin layer into a five-layer structure with a density gradient as described above, strength, heat resistance, and stretching suitability are significantly improved. Further, it is possible to effectively prevent curling in the base material. Furthermore, it is possible to effectively prevent delamination from occurring in the base material.
Moreover, the polyethylene resin layer having such a structure can be stably produced by the above-described inflation method.

The thickness of the polyethylene resin layer is preferably 10 μm or more and 50 μm or less, more preferably 10 μm or more and 40 μm or less.
By setting the thickness of the polyethylene resin layer to 10 μm or more, the strength and heat resistance of the base material can be further improved.
Further, by setting the thickness of the polyethylene resin layer to 50 μm or less, the film formability and processability of the base material can be further improved.

The polyethylene resin layer may have a printing layer on its surface, and the image formed on the printing layer is not particularly limited, and may include letters, patterns, symbols, and combinations thereof.
The printing layer can be formed on the base material using biomass-derived ink. Thereby, environmental load can be reduced.
The method for forming the printed layer is not particularly limited, and conventionally known printing methods such as gravure printing, offset printing, and flexographic printing can be used.

(Surface resin layer)
The base material included in the laminate includes a surface resin layer containing a resin material having a melting point of 150° C. or higher (hereinafter referred to as a high melting point resin material in some cases) on a polyethylene resin layer.

The melting point of the high melting point resin material is more preferably 160°C or higher.
By setting the melting point of the high melting point resin material to 160° C. or higher, the adhesion of the deposited film can be further improved, and the gas barrier properties can be further improved. Moreover, when a sealant layer is laminated, the adhesion with the sealant layer can be improved, and the lamination strength of a packaging container made from this laminate can be further improved.

The melting point of the high melting point resin material is preferably 265°C or lower, more preferably 260°C or lower, and even more preferably 250°C or lower. By setting the melting point of the high melting point resin material to 265° C. or lower, the film forming properties of the base material can be improved.

The difference between the melting point of the high melting point resin material contained in the surface resin layer and the melting point of the polyethylene contained in the polyethylene resin layer is preferably 20 to 80°C, more preferably 20 to 60°C.
When the difference between the melting point of the high melting point resin material included in the surface resin layer and the melting point of the polyethylene included in the polyethylene resin layer is 20°C or more, the adhesion of the vapor deposited film can be further improved, and the vapor deposited film It is possible to further improve the gas barrier properties of the base material formed with the . Moreover, when a sealant layer is laminated, the adhesion with the sealant layer can be improved, and the lamination strength of a packaging container made from this laminate can be further improved.
Furthermore, since the difference between the melting point of the high melting point resin material included in the surface resin layer and the melting point of the polyethylene included in the polyethylene resin layer is 80°C or less, the film formability of the base material can be further improved. .

In one embodiment, the high melting point resin material consists of a polymer having polar groups. When the high melting point resin material is made of a polymer having a polar group, it is possible to further improve the adhesion with the deposited film.

In the present invention, a polar group refers to a group containing one or more heteroatoms, such as an ester group, an epoxy group, a hydroxyl group, an amino group, an amide group, a carboxyl group, a carbonyl group, a carboxylic acid anhydride group, and a sulfone group. , a thiol group and a halogen group.
Among these, from the viewpoint of the lamination strength of the packaging container, hydroxyl groups, ester groups, amino groups, amide groups, carboxyl groups and carbonyl groups are preferred, and hydroxyl groups are more preferred.

Examples of the high melting point resin material include vinyl resin, polyamide, polyimide, polyester, (meth)acrylic resin, cellulose resin, polyolefin resin, and ionomer resin.

In the present invention, resin materials having a melting point of 150°C or higher and having polar groups are particularly preferred, such as ethylene vinyl alcohol copolymer, polyvinyl alcohol, nylon 6, nylon 6,6, nylon 6-nylon 6,6 copolymer. Amide resins such as nylon, MXD nylon, and amorphous nylon are preferred, and ethylene vinyl alcohol copolymers and amide resins are particularly preferred.
By using such a resin material, the adhesion of the vapor deposited film formed on the surface resin layer can be significantly improved, and the gas barrier properties can be effectively improved.

The content of the high melting point resin material in the surface resin layer is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. By setting the content of the high melting point resin material in the surface resin layer to 70% by mass or more, the adhesion of the vapor deposited film formed on the surface resin layer can be significantly improved, and the base material on which the vapor deposited film is formed can be improved. can effectively improve the gas barrier properties of

The surface resin layer may contain resin materials other than high melting point resin materials within a range that does not impair the characteristics of the present invention.
Note that from the viewpoint of adhesion to the deposited film, the surface resin layer preferably does not contain any resin material other than the high melting point resin material.

In addition, the surface resin layer may contain additives within a range that does not impair the characteristics of the present invention, such as a crosslinking agent, an antioxidant, an anti-blocking agent, a slip agent, an ultraviolet absorber, a light stabilizer, etc. agents, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.

The thickness of the surface resin layer is preferably 0.1 μm or more and 5 μm or less, more preferably 0.1 μm or more and 4 μm or less.
By setting the thickness of the surface resin layer to 0.1 μm or more, the adhesion of the vapor deposited film can be further improved, and the gas barrier properties of the base material on which the vapor deposited film is formed can be further improved. Moreover, when a sealant layer is laminated, the adhesion with the sealant layer can be improved, and the lamination strength of a packaging container made from this laminate can be further improved.
Moreover, by setting the thickness of the surface resin layer to 5 μm or less, the base material can be suitably used for producing monomaterial packaging containers. Furthermore, the film formability and processability of the base material can be further improved.

Further, the surface resin layer included in the base material may be subjected to surface treatment. Thereby, adhesion between adjacent layers can be improved.
The surface treatment method is not particularly limited, and includes physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and/or nitrogen gas, glow discharge treatment, and oxidation using chemicals. Examples include chemical treatments such as treatment.

The thickness of the surface resin layer is preferably 0.1 μm or more and 5 μm or less, more preferably 0.1 μm or more and 4 μm or less.
By setting the thickness of the surface resin layer to 0.1 μm or more, the adhesion of the vapor deposited film can be further improved, and the gas barrier properties of the base material on which the vapor deposited film is formed can be further improved. Moreover, when a sealant layer is laminated, the adhesion with the sealant layer can be improved, and the lamination strength of a packaging container made from this laminate can be further improved.
Moreover, by setting the thickness of the surface resin layer to 5 μm or less, the base material can be suitably used for producing monomaterial packaging containers. Furthermore, the film formability and processability of the base material can be further improved.

Further, the surface resin layer included in the base material may be subjected to surface treatment. Thereby, adhesion between adjacent layers can be improved.
The surface treatment method is not particularly limited, and includes physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and/or nitrogen gas, glow discharge treatment, and oxidation using chemicals. Examples include chemical treatments such as treatment.

(adhesive resin layer)
In one embodiment, the base material can include an adhesive resin layer between the polyethylene resin layer and the surface resin layer, thereby improving the adhesion between these layers.

The adhesive resin layer can be formed by using adhesive resins such as polyether, polyester, silicone resin, epoxy resin, polyurethane, vinyl resin, phenol resin, and polyolefin.
Among the above, polyolefins and acid-modified products thereof are preferred, and polyethylene and acid-modified products thereof are particularly preferred, since the laminate can be configured to be more suitable for monomaterial packaging containers.
As the adhesive polyethylene, commercially available ones can be used, and for example, Admer series manufactured by Mitsui Chemicals, Inc. can be used.

The thickness of the adhesive resin layer is not particularly limited, but can be, for example, 1 μm or more and 15 μm or less. By setting the thickness of the adhesive resin layer to 1 μm or more, the adhesion between the polyethylene resin layer and the surface resin layer can be further improved. By setting the thickness of the adhesive layer to 15 μm or less, the processability of the base material can be improved.

The base material is subjected to a stretching treatment, and the stretching treatment may be uniaxial stretching or biaxial stretching.
The stretching ratio of the base material in the longitudinal direction (MD direction) and the transverse direction (TD direction) is preferably 2 times or more and 15 times or less, and preferably 5 times or more and 13 times or less.
By setting the stretching ratio to 2 times or more, the strength and heat resistance of the base material can be further improved. Moreover, the suitability for printing onto a base material can be improved.
Further, from the viewpoint of the breaking limit of the base material, the stretching ratio is preferably 15 times or less.

In one embodiment, the base material is a co-pressed film, which can be produced by forming a resin film using a T-die method or an inflation method, and then stretching the resin film.
By forming the film by the inflation method, the resin film can be stretched at the same time.

(deposited film)
The laminate includes a deposited film on and adjacent to the surface resin layer. In the laminate, the vapor deposited film and the surface resin layer have high adhesion, and have extremely high gas barrier properties, specifically, oxygen barrier properties and water vapor barrier properties.
Furthermore, since the laminate includes a vapor-deposited film, a packaging container made using the laminate can suppress a decrease in mass of the contents filled therein.

The deposited film contains silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), and lead. It can be a vapor-deposited film of one or more inorganic substances or inorganic oxides such as (Pb), zirconium (Zr), and yttrium (Y). The deposited film can have a structure of two or more layers, and may be made of the same material or different materials.
Among the above, the deposited film is preferably composed of aluminum, aluminum oxide (alumina), or silicon oxide (silica) from the viewpoint of adhesion with the surface resin layer and gas barrier properties.

The surface of the deposited film is preferably subjected to the above surface treatment. Thereby, adhesion between adjacent layers can be improved.

Further, the thickness of the deposited film is preferably 1 nm or more and 150 nm or less, more preferably 5 nm or more and 60 nm or less, and even more preferably 10 nm or more and 40 nm or less.
By setting the thickness of the deposited film to 1 nm or more, the oxygen barrier properties and water vapor barrier properties of the laminate can be further improved.
Furthermore, by setting the thickness of the deposited film to 150 nm or less, a laminate can be obtained that can be suitably used for producing monomaterial packaging containers. Furthermore, generation of cracks in the deposited film can be prevented.

Conventionally known methods can be used to form the deposited film, such as physical vapor deposition (PVD) such as vacuum evaporation, sputtering, and ion plating, or plasma chemical vapor deposition (PVD). Examples include chemical vapor deposition methods (CVD methods) such as phase growth methods, thermal chemical vapor deposition methods, and photochemical vapor deposition methods.
An embodiment of a method for forming a vapor deposited film will be described below, but the method for forming a vapor deposited film is not limited to these.

A vacuum film forming apparatus with plasma assist can be used as the apparatus used in the method of forming a vapor deposited film by the PVD method.
An embodiment of a method for forming a deposited film using a vacuum film forming apparatus with plasma assist will be described below.
In one embodiment, the vacuum film forming apparatus includes a vacuum container A, a base material 10, an unwinding section B, a film forming drum C, a winding section D, a transport roll E, an evaporation source, as shown in FIGS. F, a reaction gas supply section G, an anti-deposition box H, a vapor deposition material I, and a plasma gun J.
Note that FIG. 5 is a schematic sectional view of the vacuum film forming apparatus in the XZ plane direction, and FIG. 6 is a schematic sectional view of the vacuum film forming apparatus in the XY plane direction.
As shown in FIG. 5, a base material 10 wound up using the film forming drum C method is placed in the upper part of the vacuum container A with its surface resin layer surface facing downward. An electrically grounded dust-proof box H is arranged below the drum C. The evaporation source F is arranged on the bottom of the dust-proof box H. The film-forming drum C is placed in the vacuum container A so that the surface resin layer surface of the base material 10 wound up on the film-forming drum C is located at a position facing the upper surface of the evaporation source F with a fixed interval. is placed.
Moreover, a conveyance roll E is arranged between the unwinding part B and the film-forming drum C, and between the film-forming drum C and the winding part D.
Note that the vacuum container is connected to a vacuum pump (not shown).
The evaporation source F is for holding the evaporation material I and is equipped with a heating device (not shown).
The reaction gas supply section G is a section that supplies a reaction gas (oxygen, nitrogen, helium, argon, a mixed gas thereof, etc.) that reacts with the evaporated deposition material.
The evaporation material I that has been heated and evaporated from the evaporation source F is irradiated onto the surface resin layer of the base material 10, and at the same time, plasma is irradiated from the plasma gun J toward the surface resin layer to complete the evaporation process. A membrane is formed.
Details of this forming method are disclosed in JP-A-2011-214089.

As a plasma generator used in plasma chemical vapor deposition, a generator for high frequency plasma, pulsed wave plasma, microwave plasma, etc. can be used. Further, an apparatus having two or more film forming chambers may be used. It is preferable that the apparatus is equipped with a vacuum pump and can maintain each film forming chamber in a vacuum.
The degree of vacuum in each film forming chamber is preferably 1×10 to 1×10 ⁻⁶ Pa.
An embodiment of a method for forming a deposited film using a plasma generator will be described below.
First, the base material is sent to a film forming chamber and conveyed onto a cooling/electrode drum via an auxiliary roll at a predetermined speed.
Next, a mixed gas composition containing a film-forming monomer gas containing an inorganic oxide, oxygen gas, an inert gas, etc. is supplied from the gas supply device into the film-forming chamber, and plasma is generated by glow discharge onto the surface resin layer. is generated and irradiated with this to form a deposited film containing an inorganic oxide on the surface resin layer.
Details of this forming method are disclosed in JP-A-2012-076292.

As an apparatus used in the method for forming a vapor deposited film, a continuous vapor deposition film forming apparatus including a plasma pretreatment chamber and a film forming chamber can be used.
An embodiment of a method for forming a deposited film using the apparatus will be described below.
First, in the plasma pretreatment chamber, a surface resin layer of a base material is irradiated with plasma from a plasma supply nozzle. Next, in a film forming chamber, a vapor deposition film is formed on the plasma-treated surface resin layer.
Details of this formation method are disclosed in International Publication WO2019/087960 pamphlet.

(barrier coat layer)
The laminate may further include a barrier coat layer on the deposited film. Thereby, the oxygen barrier properties and water vapor barrier properties of the laminate can be improved.

In one embodiment, the barrier coat layer is made of polyamide resins such as ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol, polyacrylonitrile, nylon 6, nylon 6,6 and polymethaxylylene adipamide (MXD6), polyester It includes gas barrier resins such as resins, polyurethane resins, and (meth)acrylic resins.

The content of the gas barrier resin in the barrier coat layer is preferably 50% by mass or more and 95% by mass or less, more preferably 75% by mass or more and 90% by mass or less. By setting the content of the gas barrier resin in the barrier coat layer to 50% by mass or more, oxygen barrier properties and water vapor barrier properties can be further improved.

The thickness of the barrier coat layer is preferably 0.01 μm or more and 10 μm or less, more preferably 0.1 μm or more and 5 μm or less.
By setting the thickness of the barrier coat layer to 0.01 μm or more, the oxygen barrier properties and water vapor barrier properties of the laminate can be further improved. By setting the thickness of the barrier coat layer to 10 μm or less, the processability of the laminate can be improved. Moreover, the recyclability of a packaging container produced using a laminate of a base material and a sealant layer made of polyethylene resin can be improved.

The barrier coat layer can be formed by dissolving or dispersing the above material in water or an appropriate solvent, applying the solution, and drying the solution. The barrier coat layer can also be formed by applying and drying a commercially available barrier coat agent.

In another embodiment, the barrier coat layer is a metal alkoxide obtained by polycondensing a mixture of a metal alkoxide and a water-soluble polymer by a sol-gel method in the presence of a sol-gel method catalyst, water, an organic solvent, etc. It is a gas barrier coating film containing at least one resin composition such as a hydrolyzate of or a hydrolyzed condensate of a metal alkoxide.
By providing such a barrier coat layer on the vapor deposited film, it is possible to effectively prevent the occurrence of cracks in the vapor deposited film.

In one embodiment, the metal alkoxide is represented by the following general formula.
R ¹ _n M(OR ² ) _m
(However, in the formula, R ¹ and R ² each represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, and m represents an integer of 1 or more. , n+m represents the valence of M.)

As the metal atom M, silicon, zirconium, titanium, aluminum, etc. can be used, for example.
Examples of the organic group represented by R ¹ and R ² include alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, and i-butyl group. I can do it.

Examples of metal alkoxides satisfying the above general formula include tetramethoxysilane (Si(OCH ₃ ) ₄ ), tetraethoxysilane (mass%) Si(OC ₂ H ₅ ) ₄ ), and tetrapropoxysilane (Si(OC ₃ H ₇ ) ₄ ), tetrabutoxysilane (Si(OC ₄ H ₉ ) ₄ ), and the like.

Moreover, it is preferable that a silane coupling agent is used together with the metal alkoxide.
As the silane coupling agent, known organoalkoxysilanes containing organic reactive groups can be used.

As the water-soluble polymer, polyvinyl alcohol and ethylene-vinyl alcohol copolymer are preferred, and from the viewpoints of oxygen barrier properties, water vapor barrier properties, water resistance, and weather resistance, it is preferable to use these in combination.

The thickness of the gas barrier coating film is preferably 0.01 μm or more and 10 μm or less, more preferably 0.1 μm or more and 5 μm or less.
By setting the thickness of the gas barrier coating film to 0.01 μm or more, the oxygen barrier properties and water vapor barrier properties of the laminate can be improved. Moreover, generation of cracks in the deposited film can be prevented.
By setting the thickness of the gas barrier coating film to 10 μm or less, it is possible to obtain a laminate that can be suitably used for producing monomaterial packaging containers.

The gas barrier coating film is prepared by applying a composition containing the above-mentioned materials by conventionally known means such as roll coating with a gravure roll coater, spray coating, spin coating, dipping, brush, barcode, applicator, etc. It can be formed by polycondensing products by a sol-gel method.
As the sol-gel method catalyst, acid or amine compounds are suitable.

The composition may further contain an acid. Acids are used as catalysts in the sol-gel process, mainly for the hydrolysis of alkoxides, silane coupling agents, and the like.
As the acid, mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid, and organic acids such as acetic acid and tartaric acid are used.

Further, the above composition may contain an organic solvent. As the organic solvent, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butanol, etc. can be used.

An embodiment of a method for forming a gas barrier coating film will be described below.
First, a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and if necessary a silane coupling agent are mixed to prepare a composition. A polycondensation reaction gradually proceeds in the composition.
Next, the composition is applied onto the deposited film by the conventionally known method described above and dried. By this drying, the polycondensation reaction of the alkoxide and the water-soluble polymer (and the silane coupling agent if the composition includes the silane coupling agent) further proceeds, and a composite polymer layer is formed.
Finally, a gas barrier coating film can be formed by heating.

(Sealant layer)
In one embodiment, the sealant layer comprises the same resin as the polyethylene resin layer of the substrate, ie, a polyethylene resin. A laminate having such a configuration can be suitably used as a laminate for producing a monomaterial packaging container.
As polyethylene resins, high-density polyethylene resins (HDPE), medium-density polyethylene resins (MDPE), low-density polyethylene resins (LDPE), linear low-density polyethylene resins (LLDPE), and very low-density polyethylene resins (VLDPE) are used. can do.
Moreover, a copolymer of ethylene and other monomers can also be used as the polyethylene resin.
Furthermore, as the polyethylene resin, a biomass-derived polyethylene resin or a mechanically recycled or chemically recycled polyethylene resin can also be used.

The content of polyethylene resin in the sealant layer is preferably 80% by mass or more, more preferably 90% by mass or more. This makes it possible to obtain a laminate that can be suitably used for producing monomaterial packaging containers.

As long as the characteristics of the present invention are not impaired, the sealant layer may contain resin materials other than polyethylene resin, such as polyolefin resins such as polypropylene resins, (meth)acrylic resins, vinyl resins, cellulose resins, and polyamide resins. , polyester resins and ionomer resins.
Note that, from the viewpoint of its recyclability, it is particularly preferable that the sealant layer does not contain any resin other than polyethylene resin.

The sealant layer can contain the above-mentioned additives within a range that does not impair the characteristics of the present invention.

The sealant layer may have a single layer structure or a multilayer structure.

The thickness of the sealant layer is preferably 20 μm or more and 100 μm or less, more preferably 30 μm or more and 70 μm or less.
By setting the thickness of the sealant layer to 20 μm or more, the laminate strength of the packaging container can be further improved.
Further, by setting the thickness of the sealant layer to 100 μm or less, the moldability of the laminate can be improved, and the packaging container can be manufactured more easily.

The sealant layer is formed by laminating a resin film made of the above resin material such as polyethylene resin with a vapor deposited film provided on the surface vapor deposited film or a barrier coat layer via a conventionally known adhesive or the like. can do.
Further, the sealant layer can be formed by melt-extruding the resin material onto the vapor deposited film provided on the surface vapor deposited film or onto the barrier coat layer.
Further, when the laminate is used for producing a laminate tube or the like, the laminate 50 further includes a sealant layer 53 on the surface of the base material 51 on which the vapor deposited film is not formed (not shown).

(Adhesive layer)
The laminate can include an adhesive layer between arbitrary layers.
The adhesive layer includes at least one type of adhesive, and may be a one-component curing type, a two-component curing type, or a non-curing type adhesive. Further, the adhesive may be a solvent-free adhesive or a solvent-based adhesive, but from the viewpoint of environmental load, a solvent-free adhesive can be preferably used.
Examples of solvent-free adhesives include polyether adhesives, polyester adhesives, silicone adhesives, epoxy adhesives, and urethane adhesives. Among these, two-component curable urethane adhesives adhesives can be preferably used.
Examples of solvent-based adhesives include rubber adhesives, vinyl adhesives, silicone adhesives, epoxy adhesives, phenolic adhesives, and olefin adhesives.

The thickness of the adhesive layer is preferably 1 μm or more and 15 μm or less, more preferably 3 μm or more and 10 μm or less. By setting the thickness of the adhesive layer to 1 μm or more, the adhesion between the layers can be improved. Further, by setting the thickness of the adhesive layer to 15 μm or less, the recyclability of the packaging bag can be improved.

(Laminated body according to second aspect)
As shown in FIG. 7, the laminate 60 includes a base material 61, an intermediate layer 62, and a sealant layer 63, and the intermediate layer 62 includes a vapor deposited film 64, a surface resin layer 65, and a polyethylene resin layer 66. Equipped with.
The intermediate polyethylene resin layer, the base material, and the sealant layer of the laminate contain the same resin, that is, polyethylene resin, and the laminate having such a structure is suitable for manufacturing monomaterial packaging containers. It can be suitably used as a laminate for.

The content of polyethylene resin relative to the total solid content contained in the laminate constituting the packaging bag is preferably 80% by mass or more, more preferably 90% by mass or more. This makes it possible to obtain a laminate that can be suitably used for producing monomaterial packaging containers (packaging bags).

Although FIG. 7 shows a configuration in which the vapor deposited film 64 and the base material 61 are adjacent to each other, the present invention is not limited to this, and as shown in FIG. It may be something.

From the viewpoint of heat-sealability of the packaging bag of the present invention produced by the barrier laminate 60, the vapor-deposited film 14 is preferably provided adjacent to the base material 51, as shown in FIG.

In one embodiment, the intermediate layer 62 can further include an adhesive resin layer 67 between the surface resin layer 65 and the polyethylene resin layer 66, as shown in FIG.

Further, in one embodiment, the stack 60 includes a barrier coat layer adjacent to the deposited film 64 (not shown).

Furthermore, in one embodiment, the laminate 60 includes an adhesive layer (not shown) between arbitrary layers, for example, between the base material 61 and the intermediate layer 62 or between the intermediate layer 62 and the sealant layer 63. ).

Each layer included in the laminate according to the second aspect will be described below.

(Base material)
The base material includes the same resin as the polyethylene resin layer and the sealant layer of the intermediate layer, ie, polyethylene resin. A laminate having such a configuration can be suitably used as a laminate for producing a monomaterial packaging container.
As polyethylene resins, high-density polyethylene resins (HDPE), medium-density polyethylene resins (MDPE), low-density polyethylene resins (LDPE), linear low-density polyethylene resins (LLDPE), and very low-density polyethylene resins (VLDPE) are used. can do.
Moreover, a copolymer of ethylene and other monomers can also be used as the polyethylene resin.
Furthermore, as the polyethylene resin, a biomass-derived polyethylene resin or a mechanically recycled or chemically recycled polyethylene resin can also be used.

The content of polyethylene resin in the base material is preferably 80% by mass or more, more preferably 90% by mass or more. This makes it possible to obtain a laminate that can be suitably used for producing monomaterial packaging containers.

As long as the characteristics of the present invention are not impaired, the base material may contain resin materials other than polyethylene resin, such as polyolefin resins such as polypropylene resins, (meth)acrylic resins, vinyl resins, cellulose resins, and polyamide resins. , polyester resins and ionomer resins.
Note that, from the viewpoint of its recyclability, it is particularly preferable that the base material does not contain any resin other than polyethylene resin.

The base material can contain the above-mentioned additives within a range that does not impair the characteristics of the present invention.

The base material may have a single layer structure or a multilayer structure.

In a base material having a multilayer structure, the densities of the polyethylene resins constituting each layer may be different, that is, the base material may be provided with a density gradient.
By providing a density gradient in the substrate, its strength, heat resistance and stretchability are significantly improved.

In a base material provided with a density gradient, if the density difference between each layer is large, there is a risk that delamination (delamination) at the interface will occur. Therefore, the density difference between each layer is preferably 0.04 g/cm ³ or less, more preferably 0.02 g/cm ³ or less.

The specific structure of the base material provided with a concentration gradient is the same as that of the polyethylene resin layer provided with a concentration gradient shown in the first aspect, and the description thereof will be omitted here.

In one embodiment, the base material is subjected to a stretching treatment, and the stretching treatment may be uniaxial stretching or biaxial stretching.
The stretching ratio of the base material in the longitudinal direction (MD direction) and the transverse direction (TD direction) is preferably 2 times or more and 15 times or less, and preferably 5 times or more and 13 times or less.
By setting the stretching ratio to 2 times or more, the strength and heat resistance of the base material can be further improved. Moreover, the suitability for printing onto a base material can be improved.
Further, from the viewpoint of the breaking limit of the base material, the stretching ratio is preferably 15 times or less.

The base material may have a printing layer on its surface, and the image formed on the printing layer is not particularly limited, and may include letters, patterns, symbols, and combinations thereof.
Print layer formation can be performed using biomass-derived ink. Thereby, environmental load can be reduced.
The method for forming the printed layer is not particularly limited, and conventionally known printing methods such as gravure printing, offset printing, and flexographic printing can be used.

Moreover, it is preferable that the base material is surface-treated. Thereby, adhesion between adjacent layers can be improved.
The surface treatment method is not particularly limited, and includes physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and/or nitrogen gas, glow discharge treatment, and oxidation using chemicals. Examples include chemical treatments such as treatment.
Alternatively, an anchor coat layer may be formed on the surface of the base material using a conventionally known anchor coat agent.

The thickness of the base material is preferably 9 μm or more and 50 μm or less, more preferably 12 μm or more and 30 μm or less. By setting the thickness of the base material within the above numerical range, the printability, strength, and heat resistance of the base material can be further improved.

(middle class)
The intermediate layer includes a vapor deposited film, a surface resin layer, and a polyethylene resin layer. In one embodiment, an adhesive resin layer is provided between the surface resin layer and the polyethylene resin layer.
The intermediate layer may be provided so that the surface on which the vapor deposited film is formed is on the base material side or may be provided on the sealant layer side. From the viewpoint of heat-sealability of the packaging bag of the invention, it is preferable that the intermediate layer is provided such that the vapor-deposited film forming surface is on the base material side.

The surface resin layer, the polyethylene resin layer, and the adhesive resin layer are subjected to a stretching treatment, and the stretching treatment may be uniaxial stretching or biaxial stretching.
The stretching ratio in the machine direction (MD direction) and the transverse direction (TD direction) is preferably 2 times or more and 15 times or less, and preferably 5 times or more and 13 times or less.
By setting the stretching ratio to 2 times or more, the strength and heat resistance of the intermediate layer can be further improved. Furthermore, suitability for printing on the intermediate layer can be improved.
Further, from the viewpoint of the breaking limit, the stretching ratio is preferably 15 times or less.

In one embodiment, the surface resin layer and the polyethylene resin layer included in the intermediate layer are co-pressed films, which are formed using a T-die method or an inflation method to form a resin film, and then stretched. It can be made.
By forming the film by the inflation method, the resin film can be stretched at the same time.

(Polyethylene resin layer)
The configuration of the polyethylene resin layer is the same as that included in the laminate of the first embodiment, and will not be described here.

(Surface resin layer)
The structure of the surface resin layer is the same as that included in the laminate of the first embodiment, and the description thereof will be omitted here.

(adhesive resin layer)
The configuration of the adhesive resin layer is the same as that included in the laminate of the first embodiment, and will not be described here.

(deposited film)
The configuration of the deposited film is the same as that included in the laminate of the first embodiment, and will not be described here.

(barrier coat layer)
The structure of the barrier coat layer is the same as that included in the laminate of the first embodiment, and the description thereof will be omitted here.

(Sealant layer)
The structure of the sealant layer is the same as that included in the laminate of the first embodiment, and the description thereof will be omitted here.

(Adhesive layer)
The structure of the adhesive layer is the same as that included in the laminate of the first embodiment, and the description thereof will be omitted here.

(Laminated body according to third aspect)
As shown in FIG. 11, the laminate 70 includes a base material 71, a deposited film 72, and a sealant layer 73, and the sealant layer 73 includes a surface resin layer 74 and a polyethylene resin layer 75.
The polyethylene resin layer of the sealant layer included in the laminate and the base material contain the same resin, that is, polyethylene resin, and the laminate having such a structure can be used as a laminate for producing a monomaterial packaging container. It can be suitably used as a body.

The content of polyethylene resin relative to the total solid content contained in the laminate constituting the packaging bag is preferably 80% by mass or more, more preferably 90% by mass or more. This makes it possible to obtain a laminate that can be suitably used for producing monomaterial packaging containers (packaging bags).

In one embodiment, the sealant layer 73 can further include an adhesive resin layer 76 between the surface resin layer 74 and the polyethylene resin layer 75, as shown in FIG.

Further, in one embodiment, the stack 70 includes a barrier coat layer adjacent to the deposited film 72 (not shown).

Furthermore, in one embodiment, the laminate 70 includes an adhesive layer between arbitrary layers, for example, between the deposited film 72 and the sealant layer 73 (not shown).

Each layer included in the laminate according to the third aspect will be described below.

(Base material)
The structure of the base material is the same as that included in the laminate of the second embodiment, and the description thereof will be omitted here.

(deposited film)
The configuration of the deposited film is the same as that included in the laminates of the first aspect and the second aspect, and will not be described here.

(Sealant layer)
The sealant layer includes a surface resin layer and a polyethylene resin layer. In one embodiment, an adhesive resin layer is provided between the surface resin layer and the polyethylene resin layer.

In one embodiment, the sealant layer is a co-pressed film, and can be produced by forming a film using a T-die method, an inflation method, or the like.

From the viewpoint of heat sealability, the sealant layer is preferably composed of an unstretched film.

(Polyethylene resin layer)
The configuration of the polyethylene resin layer is the same as that included in the laminate of the first embodiment, and will not be described here.

(Surface resin layer)
The structure of the surface resin layer is the same as that included in the laminate of the first embodiment, and the description thereof will be omitted here.

(adhesive resin layer)
The configuration of the adhesive resin layer is the same as that included in the laminate of the first embodiment, and will not be described here.

(barrier coat layer)
The structure of the barrier coat layer is the same as that included in the laminate of the first embodiment, and the description thereof will be omitted here.

(Adhesive layer)
The structure of the adhesive layer is the same as that included in the laminate of the first embodiment, and the description thereof will be omitted here.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples.

Example 1-1
Ethylene vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., EVAL E171B, melting point: 165°C, density: 1.14 g/cm ³ ),
Adhesive resin (manufactured by Mitsui Chemicals, maleic anhydride modified polyethylene, Admer NF557, density 0.920 g/cm ³ ),
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C),
A film was formed by coextrusion using an inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) using a stretching device to prepare a base material.
In the base material thus obtained, the thickness of the surface resin layer made of ethylene vinyl alcohol copolymer is 2 μm, the thickness of the adhesive resin layer is 3 μm, and the polyethylene resin layer made of medium density polyethylene. The thickness was 20 μm.

An aluminum vapor deposition film with a thickness of 30 nm was formed on the surface of the surface resin layer of the base material by a PVD method under a pressure of 3.0×10 ⁻² Pa.

A first linear low density polyethylene (manufactured by Prime Polymer Co., Ltd., SP2520, density: 0.925 g/cm ³ , melting point: 122°C), a second linear low density polyethylene (manufactured by Prime Polymer Co., Ltd., SP1520, (density 0.913, melting point 116°C) was formed into a multilayer extrusion film using an inflation molding method to produce unstretched polyethylene films of a first linear low density polyethylene film of 20 μm and a second linear low density polyethylene film of 20 μm. .
The first linear low-density polyethylene side of this unstretched polyethylene film was applied with a two-part curable urethane adhesive (manufactured by Rock Paint Co., Ltd., Ru-77T/H) onto the aluminum vapor-deposited film of the base material formed above. -7) to obtain a laminate.
The polyethylene content in the laminate is summarized in Table 1. The contents of polyethylene in the laminates and laminates obtained in the following examples and comparative examples are also summarized in Table 1.

Example 1-2
The base material was prepared in the same manner as in Example 1-1, except that the ethylene vinyl alcohol copolymer was changed to polyamide (manufactured by Ube Industries, Ltd., 5033, melting point: 196°C, density: 1.14 g/cm ³ ). The material was made.
In the base material thus obtained, the thickness of the surface resin layer made of polyamide is 2 μm, the thickness of the adhesive resin layer is 3 μm, and the thickness of the polyethylene resin layer made of medium density polyethylene is 20 μm. Met.

A laminate was produced in the same manner as in Example 1-1, except that the base material was changed to the base material produced as described above.

Example 1-3
Ethylene vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., EVAL E171B, melting point: 165°C, density: 1.14 g/cm ³ ),
Adhesive resin (manufactured by Mitsui Chemicals, maleic anhydride modified polyethylene, Admer NF557, density 0.920 g/cm ³ ),
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C) and compatibilizer (manufactured by Dow Chemical, maleic anhydride polyethylene, Retain 3000, density: 0.87 g/cm ³ ) A blend resin containing in a ratio of 8:2 on a mass basis,
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C),
A film was formed by coextrusion using an inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) using a stretching device to prepare a base material.
In the base material thus obtained, the thickness of the surface resin layer made of ethylene vinyl alcohol copolymer is 2 μm, the thickness of the adhesive resin layer is 3 μm, and the thickness of the second polyethylene layer made of blend resin is 2 μm. The thickness of the resin layer was 10 μm, and the thickness of the first polyethylene resin layer made of medium density polyethylene was 10 μm.

A laminate was produced in the same manner as in Example 1-1, except that the base material was changed to the base material produced as described above.

Example 1-4
The base material was prepared in the same manner as in Example 1-3, except that the ethylene vinyl alcohol copolymer was changed to polyamide (manufactured by Ube Industries, Ltd., 5033, melting point: 196°C, density: 1.14 g/cm ³ ). The material was made.
In the base material thus obtained, the thickness of the surface resin layer made of polyamide is 2 μm, the thickness of the adhesive resin layer is 3 μm, and the thickness of the second polyethylene resin layer made of blend resin. was 10 μm, and the thickness of the first polyethylene resin layer made of medium density polyethylene was 10 μm.

A laminate was produced in the same manner as in Example 1-1, except that the base material was changed to the base material produced as described above.

Comparative example 1-1
A single layer of medium-density polyethylene (Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C) was formed by extrusion using an inflation method, and then stretched 5 times in the longitudinal direction (MD direction) using a stretching device. This was stretched to produce a 25 μm stretched polyethylene film.

A laminate was produced in the same manner as in Example 1-1, except that the base material was changed to the stretched polyethylene film produced as described above.

Comparative example 1-2
A biaxially stretched polyester film (manufactured by Toyobo Co., Ltd., E5100) having a thickness of 12 μm was prepared.

A laminate was produced in the same manner as in Example 1-1 except that the base material was changed to the above polyester film.

Example 2-1
A laminate was produced in the same manner as in Example 1-1, except that the aluminum vapor deposited film was changed to a 20 nm thick aluminum oxide (alumina) vapor deposited film formed by the PVD method.

Example 2-2
A laminate was produced in the same manner as in Example 1-2, except that the aluminum vapor deposited film was changed to a 20 nm thick aluminum oxide (alumina) vapor deposited film formed by the PVD method.

Example 2-3
A laminate was produced in the same manner as in Example 1-3, except that the aluminum vapor deposited film was changed to a 20 nm thick aluminum oxide (alumina) vapor deposited film formed by the PVD method.

Example 2-4
A laminate was produced in the same manner as in Example 1-4, except that the aluminum vapor deposited film was changed to a 20 nm thick aluminum oxide (alumina) vapor deposited film formed by the PVD method.

Comparative example 2-1
A laminate was produced in the same manner as Comparative Example 1-1, except that the aluminum vapor deposited film was changed to a 20 nm thick aluminum oxide (alumina) vapor deposited film formed by the PVD method.

Comparative example 2-2
A laminate was produced in the same manner as Comparative Example 1-2, except that the aluminum vapor deposited film was changed to a 20 nm thick aluminum oxide (alumina) vapor deposited film formed by the PVD method.

Example 3-1
A laminate was produced in the same manner as in Example 1-1, except that the aluminum vapor-deposited film was replaced with a 20 nm thick silicon oxide (silica) vapor-deposited film formed by the CVD method.

Example 3-2
A laminate was produced in the same manner as in Example 1-2, except that the aluminum vapor-deposited film was changed to a 20 nm thick silicon oxide (silica) vapor-deposited film formed by the CVD method.

Example 3-3
A laminate was produced in the same manner as in Example 1-3, except that the aluminum vapor-deposited film was changed to a 20 nm thick silicon oxide (silica) vapor-deposited film formed by the CVD method.

Example 3-4
A laminate was produced in the same manner as in Example 1-4, except that the aluminum vapor-deposited film was changed to a 20 nm thick silicon oxide (silica) vapor-deposited film formed by the CVD method.

Comparative example 3-1
A laminate was produced in the same manner as Comparative Example 1-1, except that the aluminum vapor-deposited film was changed to a 20 nm thick silicon oxide (silica) vapor-deposited film formed by the CVD method.

Comparative example 3-2
A laminate was produced in the same manner as Comparative Example 1-2, except that the aluminum vapor deposited film was changed to a 20 nm thick silicon oxide (silica) vapor deposited film formed by the CVD method.

Example 4-1
A single layer of medium density polyethylene (Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C) was formed by extrusion using the inflation method, and then stretched 5 times in the longitudinal direction (MD direction) using a stretching device. Thus, a base material having a thickness of 25 μm was produced.

Ethylene vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., EVAL E171B, melting point: 165°C, density: 1.14 g/cm ³ ),
Adhesive resin (manufactured by Mitsui Chemicals, maleic anhydride modified polyethylene, Admer NF557, density 0.920 g/cm ³ ),
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C),
was coextruded into a film using an inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) using a stretching device to produce an intermediate layer.
In the intermediate layer thus obtained, the surface resin layer made of ethylene vinyl alcohol copolymer has a thickness of 2 μm, the adhesive resin layer has a thickness of 3 μm, and the polyethylene resin layer made of medium density polyethylene. The thickness was 20 μm.

An aluminum vapor deposition film with a thickness of 30 nm was formed on the surface of the surface resin layer of the intermediate layer by the PVD method at a pressure of 3.0×10 ⁻² Pa.

The base material and the surface on which the intermediate layer was formed were laminated via a two-component curable urethane adhesive (Ru-77T/H-7, manufactured by Rock Paint Co., Ltd.).

A single layer of linear low-density polyethylene (manufactured by Prime Polymer Co., Ltd., SP2520, density: 0.925 g/cm ³ , melting point: 122°C) was formed by extrusion using the T-die method to form an unstretched polyethylene film with a thickness of 40 μm. Created.
This unstretched polyethylene film was laminated onto the non-deposited surface of the intermediate layer via a two-component curable urethane adhesive (Ru-77T/H-7, manufactured by Rock Paint Co., Ltd.) to obtain a laminate. .
Table 2 summarizes the polyethylene content in the laminate. The contents of polyethylene in the laminates and laminates obtained in the following examples and comparative examples are also summarized in Table 2.

Example 4-2
High-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g/cm ³ , melting point: 135°C),
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C),
High-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g/cm ³ , melting point: 135°C),
A film was formed by coextrusion using an inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) using a stretching device to prepare a base material.
In the base material thus obtained, the thickness of the layer made of high-density polyethylene is 5 μm, the thickness of the layer made of medium-density polyethylene is 15 μm, and the thickness of the layer made of high-density polyethylene is 5 μm. was 5 μm.

A laminate was produced in the same manner as in Example 4-1, except that the base material was changed to the three-layer structure base material produced as described above.

Example 4-3
High-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g/cm ³ , melting point: 135°C),
High-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g/cm ³ , melting point: 135°C) and medium-density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C). , a blend resin containing 4:6 on a mass basis,
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C),
Ultra-low density polyethylene (manufactured by Dow Chemical, Affinity EG810G, density: 0.870 g/cm ³ , melting point: 55°C),
was formed into a tubular shape by an inflation molding method, comprising a layer made of high-density polyethylene, a layer made of blended resin, a layer made of medium-density polyethylene, and a layer made of ultra-low-density polyethylene. The film was extruded and the inner layers made of ultra-low density polyethylene were pressed together using a rubber roll.
The film obtained in this way has a layer composed of high-density polyethylene, a layer composed of blended resin, a layer composed of medium-density polyethylene, a layer composed of ultra-low-density polyethylene, and a layer composed of medium-density polyethylene. layer, a layer made of blended resin, and a layer made of high-density polyethylene.

The film obtained as described above was stretched 5 times in the longitudinal direction (MD direction) using a stretching device to produce a base material.
In the film obtained in this way, the thickness of the layer composed of high density polyethylene is 2.5 μm, the thickness of the layer composed of blend resin is 2.5 μm, and the thickness of the layer composed of medium density polyethylene is 6 μm. The thickness of the layer made of ultra-low density polyethylene is 2.5 μm, the thickness of the layer made of medium density polyethylene is 6.25 μm, and the thickness of the layer made of blend resin is 2.5 μm. The thickness of the layer made of high-density polyethylene was 2.5 μm.

A laminate was produced in the same manner as in Example 4-1, except that the base material was changed to a base material with a seven-layer structure produced as described above.

Example 4-4
The intermediate was prepared in the same manner as in Example 4-1, except that the ethylene vinyl alcohol copolymer was changed to polyamide (manufactured by Ube Industries, Ltd., 5033, melting point: 196°C, density: 1.14 g/cm ³ ). A layer was created.
In the intermediate layer thus obtained, the thickness of the surface resin layer made of polyamide is 2 μm, the thickness of the adhesive resin layer is 3 μm, and the thickness of the polyethylene resin layer made of medium density polyethylene is 20 μm. Met.

A laminate was produced in the same manner as in Example 4-1, except that the intermediate layer was changed to the intermediate layer produced as described above.

Example 4-5
Ethylene vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., EVAL E171B, melting point: 183°C, density: 1.14 g/cm ³ ),
Adhesive resin (manufactured by Mitsui Chemicals, Admer NF557),
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C) and compatibilizer (manufactured by Dow Chemical, maleic anhydride polyethylene, Retain 3000, density: 0.87 g/cm ³ ) A blend resin containing in a ratio of 8:2 on a mass basis,
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C),
was coextruded into a film using an inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) using a stretching device to produce an intermediate layer.
In the intermediate layer thus obtained, the thickness of the surface resin layer made of ethylene vinyl alcohol copolymer is 2 μm, the thickness of the adhesive resin layer is 3 μm, and the thickness of the second polyethylene layer made of blend resin is 2 μm. The thickness of the resin layer was 10 μm, and the thickness of the first polyethylene resin layer made of medium density polyethylene was 10 μm.

A laminate was produced in the same manner as in Example 4-1, except that the intermediate layer was changed to the intermediate layer produced as described above.

Example 4-6
The intermediate was prepared in the same manner as in Example 4-5, except that the ethylene vinyl alcohol copolymer was changed to polyamide (manufactured by Ube Industries, Ltd., 5033, melting point: 196°C, density: 1.14 g/cm ³ ). A layer was created.
In the intermediate layer thus obtained, the thickness of the surface resin layer made of polyamide is 2 μm, the thickness of the adhesive resin layer is 3 μm, and the thickness of the second polyethylene resin layer made of blend resin. was 10 μm, and the thickness of the first polyethylene resin layer made of medium density polyethylene was 10 μm.

A laminate was produced in the same manner as in Example 4-1, except that the intermediate layer was changed to the intermediate layer produced as described above.

Comparative example 4-1
After a single layer of medium density polyethylene (Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C) was formed by extrusion using an inflation method, it was stretched 5 times in the longitudinal direction (MD direction) using a stretching device. This was stretched to produce a 25 μm stretched polyethylene film.

A laminate was produced in the same manner as in Example 4-1, except that the intermediate layer was changed to the stretched polyethylene film produced as described above.

Comparative example 4-2
A biaxially stretched polyester film (manufactured by Toyobo Co., Ltd., E5100) having a thickness of 12 μm was prepared.

A laminate was produced in the same manner as in Example 4-1 except that the intermediate layer was changed to the above polyester film.

Example 5-1
A single layer of medium density polyethylene (Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C) was formed by extrusion using the inflation method, and then stretched 5 times in the longitudinal direction (MD direction) using a stretching device. Thus, a base material having a thickness of 25 μm was produced.

Ethylene vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., EVAL E171B, melting point: 165°C, density: 1.14 g/cm ³ ),
Adhesive resin (manufactured by Mitsui Chemicals, maleic anhydride modified polyethylene, Admer NF557, density 0.920 g/cm ³ ),
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C),
A sealant layer having a thickness of 40 μm was obtained by coextrusion film formation using the T-die method.
In the sealant layer thus obtained, the thickness of the surface resin layer made of ethylene vinyl alcohol copolymer is 2 μm, the thickness of the adhesive resin layer is 3 μm, and the polyethylene resin layer made of medium density polyethylene. The thickness was 35 μm.

An aluminum vapor deposition film with a thickness of 30 nm was formed on the surface of the surface resin layer of the sealant layer by the PVD method at a pressure of 3.0×10 ⁻² Pa.

The base material and the vapor deposited film forming surface of the sealant layer were laminated via a two-component curing urethane adhesive (Ru-77T/H-7, manufactured by Rock Paint Co., Ltd.) to obtain a laminate.
The polyethylene content in the laminate is summarized in Table 3. Further, the contents of polyethylene in the laminates and laminates obtained in the following Examples and Comparative Examples are also summarized in Table 3.

Example 5-2
High-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g/cm ³ , melting point: 135°C),
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C),
High-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g/cm ³ , melting point: 135°C),
A film was formed by coextrusion using an inflation molding method, and then stretched 5 times in the longitudinal direction (MD direction) using a stretching device to prepare a base material.
In the base material thus obtained, the thickness of the layer made of high-density polyethylene is 5 μm, the thickness of the layer made of medium-density polyethylene is 15 μm, and the thickness of the layer made of high-density polyethylene is 5 μm. was 5 μm.

A laminate was produced in the same manner as in Example 5-1, except that the base material was changed to the three-layer structure base material produced as described above.

Example 5-3
High-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g/cm ³ , melting point: 135°C),
High-density polyethylene (manufactured by ExxonMobil, HTA108, density: 0.961 g/cm ³ , melting point: 135°C) and medium-density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C). , a blend resin containing 4:6 on a mass basis,
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C),
Ultra-low density polyethylene (manufactured by Dow Chemical, Affinity EG810G, density: 0.870 g/cm ³ , melting point: 55°C),
was formed into a tubular shape by an inflation molding method, comprising a layer made of high-density polyethylene, a layer made of blended resin, a layer made of medium-density polyethylene, and a layer made of ultra-low-density polyethylene. The film was extruded and the inner layers made of ultra-low density polyethylene were pressed together using a rubber roll.
The film obtained in this way has a layer composed of high-density polyethylene, a layer composed of blended resin, a layer composed of medium-density polyethylene, a layer composed of ultra-low-density polyethylene, and a layer composed of medium-density polyethylene. layer, a layer made of blended resin, and a layer made of high-density polyethylene.

The film obtained as described above was stretched 5 times in the longitudinal direction (MD direction) using a stretching device to produce a base material.
In the film obtained in this way, the thickness of the layer composed of high density polyethylene is 2.5 μm, the thickness of the layer composed of blend resin is 2.5 μm, and the thickness of the layer composed of medium density polyethylene is 6 μm. The thickness of the layer made of ultra-low density polyethylene is 2.5 μm, the thickness of the layer made of medium density polyethylene is 6.25 μm, and the thickness of the layer made of blend resin is 2.5 μm. The thickness of the layer made of high-density polyethylene was 2.5 μm.

A laminate was produced in the same manner as in Example 5-1, except that the base material was changed to a base material with a seven-layer structure produced as described above.

Example 5-4
A sealant was prepared in the same manner as in Example 5-1, except that the ethylene vinyl alcohol copolymer was changed to polyamide (manufactured by Ube Industries, Ltd., 5033, melting point: 196°C, density: 1.14 g/cm ³ ). A layer was created.
In the sealant layer thus obtained, the thickness of the surface resin layer made of polyamide is 2 μm, the thickness of the adhesive resin layer is 3 μm, and the thickness of the polyethylene resin layer made of medium density polyethylene is 35 μm. Met.

A laminate was produced in the same manner as in Example 5-1, except that the sealant layer was changed to the sealant layer produced as described above.

Example 5-5
Ethylene vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., EVAL E171B, melting point: 183°C, density: 1.14 g/cm ³ ),
Adhesive resin (manufactured by Mitsui Chemicals, Admer NF557),
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C) and compatibilizer (manufactured by Dow Chemical, maleic anhydride polyethylene, Retain 3000, density: 0.87 g/cm ³ ) A blend resin containing in a ratio of 8:2 on a mass basis,
Medium density polyethylene (manufactured by Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129°C),
A sealant layer was prepared by co-extrusion using the T-die method.
In the sealant layer thus obtained, the thickness of the surface resin layer made of ethylene vinyl alcohol copolymer is 2 μm, the thickness of the adhesive resin layer is 3 μm, and the thickness of the second polyethylene layer made of blend resin is 2 μm. The thickness of the resin layer was 10 μm, and the thickness of the first polyethylene resin layer made of medium density polyethylene was 10 μm.

A laminate was produced in the same manner as in Example 5-1, except that the sealant layer was changed to the sealant layer produced as described above.

Example 5-6
A sealant was prepared in the same manner as in Example 1-5, except that the ethylene vinyl alcohol copolymer was changed to polyamide (manufactured by Ube Industries, Ltd., 5033, melting point: 196°C, density: 1.14 g/cm ³ ). A layer was created.
In the sealant layer thus obtained, the thickness of the surface resin layer made of polyamide is 2 μm, the thickness of the adhesive resin layer is 3 μm, and the thickness of the second polyethylene resin layer made of blend resin. was 10 μm, and the thickness of the first polyethylene resin layer made of medium density polyethylene was 10 μm.

A laminate was produced in the same manner as in Example 5-1, except that the sealant layer was changed to the sealant layer produced as described above.

Comparative example 5-1
A single layer of medium density polyethylene (Dow Chemical, Elite 5538, density: 0.941 g/cm ³ , melting point: 129° C.) was formed by extrusion using an inflation molding method to produce a 40 μm unstretched polyethylene film.

A laminate was produced in the same manner as in Example 5-1, except that the sealant layer was changed to the unstretched polyethylene film produced as described above.

<<Gas barrier evaluation>>
The oxygen permeability (cc/m ² ·day · atm) and water vapor permeability (g/m ² ·day) of the laminates and laminates obtained in the Examples and Comparative Examples were measured by the following method. The results are summarized in Tables 1 to 3.

[Oxygen permeability]
Using an oxygen permeability measuring device (MOCON, OX-TRAN2/20), set the test piece so that the base material side faces the oxygen supply side, and test at 23°C and relative humidity according to JIS K 7126. Oxygen permeability was measured in a 90% RH environment.
[Water vapor permeability]
Using a water vapor permeability measuring device (manufactured by MOCON, PERMATRAN-w 3/33), set the test piece so that the base material side is on the water vapor supply side, and heat it at 40°C in accordance with JIS K 7129. Water vapor permeability was measured in an environment with relative humidity of 90% RH.

<<Laminate strength test>>
Samples obtained by cutting the laminates and laminates into strips of 15 mm width obtained in the above Examples and Comparative Examples were tested using a tensile tester (Tensilon Universal Material Tester, manufactured by Orientec Co., Ltd.) according to JIS K6854. -2, the laminate strength (N/15 mm) between the vapor deposited film and the surface resin layer (example) and between the vapor deposited film and the polyethylene film or polyester film (comparative example) was measured at a peeling speed of 50 mm/ Measurement was performed using 90° peeling (T-peel method) at min. The measurement results are summarized in Tables 1 to 3.

10: Packaging bag, 20: Standing pouch, 31: Easy opening means, 32: Notch part, 33: Half cut line, 41: Extraction nozzle part, 42: Curved part, 43: Cutting part, 50: First aspect 51: Base material, 52: Deposited film, 53: Sealant layer, 54: Polyethylene resin layer, 55: Surface resin layer, 56: Adhesive resin layer, 60: Laminate according to the second aspect, 61: base material, 62: intermediate layer, 63: sealant layer, 64: vapor deposited film, 65: surface resin layer, 66: polyethylene resin layer, 67: adhesive resin layer, 70: laminate according to the third embodiment, 71: Base material, 72: Deposited film, 73: Sealant layer, 74: Surface resin layer, 75: Polyethylene resin layer, 76: Adhesive resin layer

Claims (10)

A packaging bag made of a laminate including at least a base material, an intermediate layer, and a sealant layer,
The intermediate layer includes a polyethylene resin layer, a surface resin layer, and a vapor deposited film provided on the surface resin layer,
The base material and the sealant layer are both made of polyethylene resin,
The surface resin layer of the intermediate layer includes a resin material having a melting point of 150° C. or higher,
The polyethylene resin layer and the surface resin layer of the intermediate layer are subjected to a stretching treatment, and the content of polyethylene resin in the entire laminate is 80% by mass or more.
packaging bag. A packaging bag made of a laminate including at least a base material, a vapor deposited film, and a sealant layer,
The sealant layer includes a surface resin layer and a polyethylene resin layer,
The base material is made of polyethylene resin,
The surface resin layer of the sealant layer contains a resin material having a melting point of 150° C. or higher,
The vapor deposited film is provided on the surface resin layer of the sealant layer, and the content of polyethylene resin in the entire laminate is 80% by mass or more,
packaging bag. The packaging bag according to claim 1 or 2, wherein the surface resin layer contains a resin material having a melting point of 150°C or more and 265°C or less. The packaging bag according to any one of claims 1 to 3, wherein a difference in melting point between the polyethylene resin and a resin material having a melting point of 150°C or higher contained in the surface resin layer is 20 to 80°C. The packaging bag according to any one of claims 1 to 4, wherein the resin material of the surface resin layer is made of a polymer having a polar group. The resin material of the surface resin layer is selected from ethylene vinyl alcohol copolymer, polyvinyl alcohol, polyester, nylon 6, nylon 6,6, nylon 6-nylon 6,6 copolymer, MXD nylon, and amorphous nylon. The packaging bag according to any one of claims 1 to 5, which is made of the above resin material. The packaging bag according to any one of claims 1 to 6, wherein the polyethylene resin layer has a multilayer structure. The packaging bag according to claim 7, wherein the polyethylene resin layer includes at least one layer containing a compatibilizer. The packaging bag according to claim 8, wherein the surface resin layer is provided so as to be in contact with a layer containing a compatibilizer of the polyethylene resin layer. The packaging bag according to any one of claims 1 to 9, wherein in the laminate, a barrier coat layer is further provided on the vapor-deposited film.