JP7782155B2 - Laminated film, packaging bag, and packaging body - Google Patents

Description

The present invention relates to a laminated film, a packaging bag, and a package.

Packaging materials used to package packaged items are required to have the ability to prevent deterioration of the packaged items. For example, a known packaging material is a packaging bag made by bonding together a pair of laminated films. Such packaging bags are required to have excellent sealing properties to prevent deterioration of the packaged items.

Examples of packaged items include food products. When food products containing sulfur-containing amino acids, such as meat products and egg products, are sterilized by boiling or retort, a distinctive odor can be generated. This odor is caused by sulfur compounds such as hydrogen sulfide that are generated by hydrolysis of the sulfur-containing amino acids. Patent Documents 1 and 2 propose providing a layer containing a polyvalent metal compound in the packaging bag to reduce this retort odor.

JP 2014-61682 A JP 2017-94533 A

However, the above-described conventional techniques have the following problems.
The packaged items are diverse and contain various components. Certain components may react with components constituting each layer of the laminated film forming the packaging bag, affecting the laminate strength. For example, the layer formed from the polyvalent metal compound in Patent Document 1 may affect the laminate strength between the layers of the laminated film depending on the components contained in the packaged item.

The present invention was made in consideration of the above-mentioned problems, and provides a laminated film, packaging bag, and package that can reduce retort odor and has good laminate strength.

In order to achieve the above object, the present invention employs the following means.
That is, the laminated film of the present invention comprises a predetermined layer, an adhesive layer containing an adhesive component and polyvalent metal particles or polyvalent metal compound particles mixed with the adhesive component, and a sealant layer laminated in this order, wherein the ratio of the maximum diameter of the aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles to the minimum diameter of the aggregates is 14.0 or less, the adhesive layer contains 0.5% by mass or more and 10% by mass or less of the polyvalent metal particles or the polyvalent metal compound particles, the average particle diameter of the polyvalent metal particles or the polyvalent metal compound particles is 5 nm or more and 100 nm or less, and the average aggregate diameter of the aggregates is 150 nm or less .

Furthermore, in the laminate film according to the present invention, the average aggregate diameter of the aggregates may be 150 nm or less.

Furthermore, in the laminated film according to the present invention, there may be 60 or more aggregates having a size that is 10 to 200% of the average particle diameter.

Furthermore, the laminated film of the present invention may not have aggregates with a diameter of 3.0 μm or more.

Furthermore, in the laminated film according to the present invention, the distance between aggregates, which is the average value of the distance between adjacent aggregates having a diameter similar to the average aggregate diameter, may be 3.0 μm or less.

In addition, in the laminate film according to the present invention, the specified layer may be a substrate film having a barrier layer.

In addition, in the laminate film according to the present invention, the base film may have a nylon layer.

Furthermore, in the laminate film according to the present invention, the average particle diameter of the polyvalent metal particles or the polyvalent metal compound particles may be 10 nm or more and 45 nm or less.

In the laminate film according to the present invention, the polyvalent metal particles or the polyvalent metal compound particles may have a specific surface area of 1 m ² /g or more.

In addition, in the laminate film according to the present invention, the adhesive layer may further contain a dispersant that disperses the polyvalent metal particles or the polyvalent metal compound particles in the adhesive component.

Furthermore, in the laminated film according to the present invention, the adhesive component may be a cured product of a two-component curing adhesive.

The packaging bag according to the present invention is a packaging bag formed by laminating films, and the films include any one of the laminated films described above.

The packaging body according to the present invention comprises the packaging bag described above and an item to be packaged contained within the packaging bag.

Furthermore, in the package according to the present invention, the packaged item may contain a sulfur compound.

The laminated film, packaging bag, and packaging body of the present invention can reduce retort odor and have good laminate strength.

1 is a schematic cross-sectional view showing an example of a laminated film according to a first embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing an example of a laminated film according to a second embodiment of the present invention. FIG. 10 is a schematic cross-sectional view showing an example of a laminated film according to a third embodiment of the present invention. FIG. 10 is a schematic front view showing an example of a packaging bag and a package according to a fourth embodiment of the present invention. FIG. 10 is a schematic perspective view showing a method for manufacturing a packaging bag according to a fourth embodiment of the present invention. FIG. 10 is a schematic perspective view showing an example of a packaging bag and a package according to a fifth embodiment of the present invention. 10 is an example of an image observed by SEM in Example 2. 10 is an example of an image observed by SEM in Comparative Example 5.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In all drawings, even if the embodiments are different, the same or corresponding components are given the same reference numerals, and common explanations will be omitted. Positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings unless otherwise specified.
Hereinafter, when multiple preferred numerical ranges are exemplified within a specific numerical range, the combinations of the upper and lower limit values are not limited to the exemplified combinations as long as they are included in the maximum preferred numerical range, unless otherwise specified. For example, when x1<x2<x3<x4 is assumed and "x1 or more and x4 or less" and "x2 or more and x3 or less" are exemplified as preferred ranges of the quantity X, each numerical range such as "more than x1 but less than x4,""x2 or more and x4 or less," and "x3 or more and x4 or less" are also preferred ranges.

[First embodiment]
A laminated film according to a first embodiment of the present invention will be described.
FIG. 1 is a schematic cross-sectional view showing an example of a laminated film according to a first embodiment of the present invention.

The laminate film 50 of this embodiment shown in FIG. 1 includes a base film (predetermined layer) 10, an adhesive layer 20, and a sealant layer 30. The base film 10, adhesive layer 20, and sealant layer 30 in the laminate film 50 are laminated in this order. The base film 10, adhesive layer 20, and sealant layer 30 each have optical transparency that allows visible light to pass through. Therefore, the laminate film 50 has a light-transmitting portion that transmits visible light in the thickness direction (the vertical direction in the figure). In the example shown in FIG. 1, the light-transmitting portion is the entire laminate film 50. Note that the laminate film 50 does not necessarily have a light-transmitting portion.
The light-transmitting portion of the laminate film 50 has a haze of 30% or less as measured in accordance with the haze measurement method specified in JIS-K-7136. Hereinafter, the haze specified in JIS-K-7136 will be simply referred to as "haze."

The base film 10 has a resin layer 12 and a barrier layer 14. Note that the base film 10 does not necessarily have to have the barrier layer 14.

The resin layer 12 is made of, for example, a resin film.
Examples of resin films include polyester films made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc.; polyolefin films made of polyethylene, polypropylene, etc.; polystyrene films; polyamide films made of polyamides such as 66-nylon; polycarbonate films; polyacrylonitrile films; polyimide films; and engineering plastic films made of other engineering plastics.
The resin film constituting the resin layer 12 may be one of the above-mentioned types used alone or a combination of two or more types.
For example, the resin layer 12 may be formed by laminating a plurality of resin films of the same type.
The resin film may be either a stretched film or an unstretched film. The resin film may be a multilayer film in which at least one stretched film and at least one unstretched film are laminated together.
The resin layer 12 may have a film that is optionally biaxially stretched, which can improve the mechanical strength and dimensional stability.

In particular, from the viewpoint of achieving both strength and flexibility, the resin layer 12 preferably includes one or both of a polyester film and a biaxially oriented polypropylene film.
Particularly from the viewpoint of improving strength and reducing costs, the resin layer 12 more preferably includes one or both of a polypropylene film and a polyethylene terephthalate film.
It is more preferable that the resin layer 12 contains a nylon film, particularly from the viewpoint of improving strength. Nylon film has excellent flexibility and is therefore less likely to develop pinholes. Therefore, when a package is formed using a packaging bag using the laminated film 50, it is possible to prevent pinholes from developing in the laminated film 50, which would cause deterioration of the packaged item. This effect is particularly useful when the packaged item is food.

The thickness of the resin layer 12 is not particularly limited and can be determined depending on the application or required properties. The thickness of the resin layer 12 may be, for example, 3 μm or more and 100 μm or less, and more preferably 6 μm or more and 50 μm or less.
The resin layer 12 may contain an appropriate additive, such as at least one selected from the group consisting of a filler, an antistatic agent, a plasticizer, a lubricant, and an antioxidant.

The surface 12a of the resin layer 12 is the surface that forms the outer surface of the laminated film 50 when forming a packaging bag.
The surface 12b of the resin layer 12 is the surface opposite to the surface 12a in the thickness direction, and is the surface to be bonded to the barrier layer 14 described later.
The laminated film 50 may be subjected to an appropriate surface treatment. For example, the surface 12b may be subjected to an appropriate surface treatment to improve the adhesion of the barrier layer 14. Examples of the surface treatment include at least one treatment selected from chemical treatment, solvent treatment, corona treatment, plasma treatment, and ozone treatment.

The barrier layer 14 is a layer that has a barrier property against at least oxygen and water vapor. The barrier layer 14 is laminated on the surface 12b of the resin layer 12.
The number of layers in the barrier layer 14 is not particularly limited as long as it includes at least one layer having a barrier property.
For example, examples of the barrier layer 14 that is made of a single layer include a vapor-deposited layer made of an inorganic material, and a barrier film made of a resin having barrier properties.
For example, when the barrier layer 14 is made up of multiple layers, it may be a barrier film in which the surface of a resin film or the like is coated with an inorganic substance having barrier properties.
Examples of inorganic substances that can be used for the barrier layer 14 include silica, aluminum, silicon, etc. When the barrier layer 14 is formed as a single layer, such inorganic substances may be vapor-deposited on the surface of the resin layer 12.
Examples of barrier films that can be used for the barrier layer 14 include nylon-based barrier films and ethylene vinyl alcohol-based barrier films. When the barrier layer 14 is formed as a single layer, such a barrier film may be laminated on the resin layer 12 by extrusion lamination, dry lamination, wet coating, or the like.
For example, when a barrier film coated with an inorganic substance is used as the barrier layer 14, the inorganic substance may be silica, aluminum, silicon, etc. In this case, the barrier film may be laminated on the resin layer 12 by dry lamination or the like.
The barrier layer 14 may be formed of one of the above-exemplified materials alone or in combination of two or more thereof.

There is no particular limitation on the thickness of the barrier layer 14. For example, when the barrier layer 14 is made of a vapor-deposited layer, the thickness may be 5 nm or more and 100 nm or less.
The barrier layer 14 can be formed by, for example, vacuum deposition, sputtering, ion plating, plasma chemical vapor deposition (CVD), dry lamination, extrusion lamination, or the like.

The adhesive layer 20 is a layer that bonds the barrier layer 14 to a sealant layer 30, which will be described later.
The adhesive layer 20 contains an adhesive component and polyvalent metal particles or polyvalent metal compound particles mixed in the adhesive component.

Examples of adhesive components include cured products of urethane adhesives, polyester adhesives, polyamide adhesives, epoxy adhesives, and isocyanate adhesives.
The adhesive component in the adhesive layer 20 is preferably formed from a two-component curing adhesive, since this makes it easier to prevent the polyvalent metal particles or polyvalent metal compound particles described below from deteriorating.
This effect of inhibiting deterioration tends to be even more pronounced when a two-component curing urethane adhesive is used, and therefore, among two-component curing adhesives, it is particularly preferable to use a urethane adhesive.

The polyvalent metal particles are particles formed of a metal that generates polyvalent ions (hereinafter referred to as a polyvalent metal). The polyvalent metal compound particles are particles formed of a compound of a polyvalent metal.
The polyvalent metal particles or polyvalent metal compound particles are used for the purpose of capturing substances that cause retort odors (hereinafter sometimes referred to as odor-causing substances), such as sulfur compounds, within the adhesive layer 20. Examples of sulfur compounds that cause odors include hydrogen sulfide, mercaptan, sulfur dioxide, and sulfur trioxide.
Although the principle by which polyvalent metal particles and polyvalent metal compound particles can capture odor-causing substances has not been theoretically elucidated, their effectiveness in reducing odor-causing substances can be confirmed experimentally.
The polyvalent metal particles and polyvalent metal compound particles mixed in the adhesive layer 20 are not particularly limited as long as they have the effect of capturing compounds that cause retort odor and can exist stably inside the adhesive component of the adhesive layer 20.

Examples of polyvalent metal particles that may be used include particles of alkaline earth metals such as beryllium, magnesium, and calcium; particles of transition metals such as titanium, zirconium, chromium, manganese, iron, cobalt, nickel, copper, and zinc; and aluminum particles.
The polyvalent metal particles may have an oxide film formed on the surface or may be coated so that they can be more stably present inside the adhesive layer 20 .

Examples of polyvalent metal compound particles include particles of polyvalent metal oxides, hydroxides, carbonates, organic acid salts (e.g., acetates), inorganic acid salts, etc. Examples of polyvalent metal compound particles that may be used include particles of ammonium complexes of polyvalent metal oxides, secondary to quaternary amine complexes of polyvalent metal oxides, or carbonates or organic acid salts thereof.
It is more preferable to use polyvalent metal compound particles, as they are more likely to be present stably inside the adhesive layer 20 .
From the viewpoints of stability in the adhesive component and ease of production, it is more preferable to use particles of zinc compounds, aluminum compounds, magnesium compounds, etc. As the polyvalent metal compound particles, from the viewpoints of ease of handling and cost, it is particularly preferable to use particles of zinc oxide, aluminum oxide, magnesium oxide, etc.

For simplicity, the polyvalent metal particles or polyvalent metal compound particles mixed in the adhesive component may be referred to as "additive particles" below.
In the adhesive layer 20, one or more types of additive particles may be mixed into the adhesive component.

The content of the additive particles in the adhesive layer 20 is not particularly limited.
The higher the content of additive particles, the greater the amount of odor-causing substances captured, making it easier to suppress retort odor. On the other hand, if the content of additive particles is too high, the lamination strength of the adhesive layer 20 may be easily reduced, and the transparency of the laminate film 50 may be reduced.
For example, in order to easily achieve both the laminate strength of the adhesive layer 20 and the transparency of the laminated film, as well as the effect of reducing retort odor, the content of additive particles in the adhesive layer 20 is more preferably 0.5% by mass or more and 10% by mass or less, and even more preferably 1.5% by mass or more and 5% by mass or less.
If the content of additive particles is less than 1% by mass, the effect of suppressing retort odor may be too low.
If the content of the additive particles exceeds 10% by mass, the lamination strength of the adhesive layer 20 may become too low, or the transparency of the laminated film may become too low.

It is more preferable that the distribution of the additive particles in the adhesive layer 20 is less biased. For example, if the distribution of the additive particles is concentrated in a specific area due to aggregation or the like, unevenness in the transparency of the laminate film 50 is likely to occur. The bias in the distribution of the additive particles in the adhesive layer 20 can also cause a decrease in haze and a decrease in laminate strength.
In particular, when large aggregates of additive particles are formed in the adhesive layer 20, granular unevenness becomes noticeable. In particular, when granular unevenness is closely arranged, streaks are formed and become even more noticeable. For example, when the laminated film 50 is used in a packaging bag and the light-transmitting portion allows the contents of the packaging bag to be visible from the outside, it is preferable that granular unevenness and streaks are not visible.

For example, from the viewpoint of improving the lamination strength of adhesive layer 20, the ratio of the maximum diameter of the aggregates to the minimum diameter of the aggregates is preferably 14.0 or less. Also, the average aggregate diameter of the aggregates is preferably 150 nm or less.
The diameter of the aggregates is measured by cutting the laminated film 50 with a microtome and observing the cross section with an SEM. Five consecutive 10 μm images are taken along the adhesive layer 20 at a magnification of 10,000 times. The maximum length of the diameters (major axes) of the aggregates contained in the five images is defined as the "maximum diameter of the aggregate." The minimum length of the diameters of the aggregates contained in the five images is defined as the "minimum diameter of the aggregate." The "maximum diameter of the aggregate" divided by the "minimum diameter of the aggregate" is the "magnification of the maximum diameter of the aggregate to the minimum diameter of the aggregate." The "average aggregate diameter of the aggregates" is the sum of all the diameters (major axes) of the aggregates contained in the five images divided by the number of aggregates.
Here, the term "aggregate" is used in a broad sense and refers to an apparent mass when observed in the thickness direction using a microscope, etc. It is not particularly distinguished whether the apparent mass is formed by the aggregation phenomenon of additive particles or whether it appears as a mass due to a high distribution density in a certain region when viewed in the thickness direction.

For example, the additive particles are believed to trap odor-causing substances that permeate the adhesive layer 20 by adsorbing them.
In order for the additive particles to efficiently capture odor-causing substances, the larger the specific surface area of the additive particles, the more preferable. Here, the specific surface area represents the surface area per unit mass of the additive particles. For example, the specific surface area of the additive particles may be 1 m ² /g or more, and more preferably 5 m ² /g or more.
If the specific surface area is large, the particle size of the additive particles becomes too small, and for example, they become more likely to scatter into the environment, so care must be taken when handling them. From the viewpoint of making the additive particles easier to handle in the manufacturing process, the specific surface area of the additive particles may be 100 m ² /g or less, and more preferably 50 m ² /g.

If the average particle size of the additive particles as primary particles is too large, aggregates exceeding 3.0 μm are likely to be formed, so it is preferable that the average particle size of the additive particles is small. However, if the average particle size of the additive particles is small to a certain extent, the maximum size of the aggregates will change depending on the mixing method in the production process, and the correlation between the average particle size and the maximum size of the aggregates will be weak.
Hereinafter, unless otherwise specified, the average particle size of the primary particles of additive particles will be simply referred to as the average particle size of additive particles. The average particle size is calculated from the equivalent circle diameter obtained from an image of the powder magnified 50,000 to 200,000 times using a transmission electron microscope (TEM), using the following general formula: Average particle size = Sum of equivalent circle diameters of measured particles / Number of measured particles (the number of measured particles is at least 100 or more).
The average particle size of the additive particles is not particularly limited, but may be, for example, 5 nm or more and 100 nm or less, more preferably 10 nm or more and 60 nm or less, and even more preferably 20 nm or more and 45 nm or less.
For example, if the average particle size of the additive particles is less than 5 nm, the production cost may increase and handling during the production process may become difficult.
For example, if the average particle size of the additive particles exceeds 100 nm, the specific surface area will be small, which may reduce the effect of capturing odor-causing substances.

In order to reduce the size of the agglomerates of additive particles in the adhesive component, the adhesive layer 20 may contain 1 part by mass or more and 50 parts by mass or less of a dispersant per 100 parts by mass of additive particles.
The type of dispersant is not particularly limited as long as it can disperse additive particles in the liquid adhesive component used to form the adhesive component.
Examples of dispersants include (poly)ester salts, polyether phosphate esters, alkyl sulfate salts, alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylsulfosuccinates, alkyldiphenyletherdisulfonates, alkylphosphate salts, aromatic phosphate esters, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, polyoxyethylene alkyl esters, alkylallyl sulfate salts, polyoxyethylene alkyl phosphate esters, sorbitan alkyl esters, glycerin fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, polyethylene glycol fatty acid esters, polyoxyethylene sorbitan alkyl esters, polyoxyethylene alkylallyl ethers, polyoxyethylene derivatives, polyoxyethylene sorbitol fatty acid esters, polyoxy fatty acid esters, polyoxyethylene alkylamines, vinyl chloride-vinyl acetate copolymers, etc. These dispersants may be used alone or in combination of two or more.

The lamination strength of the adhesive layer 20 is measured in accordance with JIS Z 0238:1998 using a Tensilon tensile tester by a T-peel method (crosshead speed: 300 mm/min).
The lamination strength of the adhesive layer 20 may be, for example, 6 N/15 mm width or more, and more preferably 7 N/15 mm width or more.

The thickness of the adhesive layer 20 is not particularly limited as long as it provides good lamination strength when the laminated film 50 is formed into a packaging bag and has a good effect of reducing odor-causing substances.
The thickness of the adhesive layer 20 may be, for example, 0.01 μm or more and 5 μm or less, and more preferably 0.03 μm or more and 3 μm or less.
If the thickness of the adhesive layer 20 is less than 0.01 μm, the laminate strength may decrease and the amount of odor-causing substances captured may be too small.
If the thickness of the adhesive layer 20 exceeds 5 μm, the laminated film 50 may become too thick.

The sealant layer 30 is a layer for bonding the laminate film 50 to another laminate film by heat fusion. The sealant layer 30 is not particularly limited as long as it can be melted by heat and mutually fused with the sealant layer of another laminate film.
Examples of materials for the sealant layer 30 include resins such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-methacrylic acid copolymer, and ethylene-propylene copolymer. The resin used for the sealant layer 30 may be any one of the exemplified resins used alone or a combination of two or more thereof.
For example, when the laminated film 50 is used to form a package that is to be sterilized by boiling or retort, it is more preferable that the sealant layer 30 contains unstretched polypropylene resin in order to maintain sufficient adhesion.

The sealant layer 30 may be formed by laminating a resin composition onto the adhesive layer 20 through extrusion lamination to form a film, or by laminating a film-formed sheet onto the adhesive layer 20 .
The thickness of the sealant layer 30 may be, for example, 10 μm or more and 150 μm or less, and more preferably 30 μm or more and 80 μm or less.

Next, an example of a method for manufacturing the laminated film 50 will be described.
First, a substrate film 10 is prepared in which a barrier layer 14 is laminated on a resin film on which a resin layer 12 is to be formed.
Thereafter, the adhesive layer 20 and the sealant layer 30 are laminated in this order on the barrier layer 14 of the base film 10 .
As a lamination method, for example, dry lamination may be used.
For example, a coating liquid is prepared by mixing additive particles with an adhesive that will form the adhesive component of the adhesive layer 20 after hardening, and the coating liquid is applied to the surface of the barrier layer 14 of the base film 10 using a dry lamination machine, followed by drying, and the resin film that forms the sealant layer 30 and the base film 10 are thermocompressed together using a heated roll.
The method for applying the coating liquid is not particularly limited. For example, the coating liquid can be applied using a coater such as a roll coater, a reverse roll coater, a gravure coater, a microgravure coater, a knife coater, a bar coater, a wire bar coater, a die coater, a dip coater, or a spin coater.
As a lamination method, a non-sol laminator can be used, and a coating liquid containing non-sol adhesive additive particles can also be used as the adhesive component of the adhesive layer 20.

When preparing the coating liquid, it is more preferable to mix the additive particles with the adhesive that forms the adhesive component and stir the mixture sufficiently so that the size of the additive particle aggregates is 3.0 μm or less. By stirring, the additive particles are dispersed in the coating liquid.
In order to reduce the size of the additive particle aggregates, it is more preferable to add a dispersant to the coating liquid. The dispersant may be added directly to the adhesive together with the additive particles. However, it is more preferable to prepare a coating liquid by dispersing the additive particles and the dispersant in a solvent to form a particle dispersion, and then mixing and stirring the particle dispersion with the adhesive. In this case, the dispersion of the additive particles in the coating liquid is promoted.
It is more preferable to subject the additive particles to a physical defibration treatment for pulverizing the additive particles while they are mixed with the dispersant and the solvent, which promotes pulverization and dispersion of the additive particles in the coating liquid.
Examples of physical defibration treatments include mechanical treatments such as high-pressure homogenizers, ultra-high-pressure homogenizers, ball mills, roll mills, cutter mills, planetary mills, jet mills, attritors, grinders, juicer mixers, homomixers, ultrasonic homogenizers, nanogenizers, and underwater counter-collision.

By carrying out a dispersion treatment to disperse the finely divided additive particles in the coating liquid using one or more of the above-mentioned means, it is possible to suppress the growth of aggregates in the coating liquid.
By carrying out the dispersion treatment, the occurrence of precipitation in the coating liquid is also suppressed, so that the additive particles can be efficiently dispersed in the coating liquid.
Once the coating liquid is prepared, it is more preferable to perform a filtration treatment before coating.

The laminated film 50 includes a barrier layer 14 that provides a barrier against oxygen and water vapor, thereby preventing oxygen and water vapor that have permeated the resin layer 12 from permeating through the adhesive layer 20 and sealant layer 30. This prevents oxygen, water vapor, and the like from penetrating into the packaging bag. As a result, in a package in which the packaged item is placed in a packaging bag formed from the laminated film 50, deterioration of the packaged item due to at least one of oxygen and water vapor can be prevented. Deterioration of polyvalent metal particles or polyvalent metal compound particles due to at least one of oxygen and water vapor penetrating from the outside can also be prevented.

The laminate film 50 has an adhesive layer 20 containing polyvalent metal particles or polyvalent metal compound particles between the base film 10 and the sealant layer 30, and is therefore able to adsorb odor-causing substances such as sulfur compounds that have permeated into the adhesive layer 20 through the sealant layer 30. Therefore, in a package in which an item is placed in a packaging bag formed from the laminate film 50, odor-causing substances such as sulfur compounds derived from the packaged item are captured by the polyvalent metal particles or polyvalent metal compound particles as they permeate the adhesive layer 20. As a result, the retort odor in the packaged item can be reduced.
The inclusion of polyvalent metal particles or polyvalent metal compound particles prevents a decrease in the laminate strength of the adhesive layer 20. The polyvalent metal particles or polyvalent metal compound particles are mixed into the adhesive component of the adhesive layer 20, which also prevents the polyvalent metal particles or polyvalent metal compound particles from reacting with components such as acetic acid and amino acids contained in the packaged goods and causing deterioration. This makes it difficult for the effect of reducing odor-causing substances and the laminate strength to decrease over time.

As described above, the laminated film 50 of this embodiment can reduce retort odor and provide a laminated film with good laminate strength.

Second Embodiment
A laminated film according to a second embodiment of the present invention will now be described.
FIG. 2 is a schematic cross-sectional view showing an example of a laminated film according to a second embodiment of the present invention.

The laminated film 60 of this embodiment shown in FIG. 2 includes a base film (predetermined layer) 10A instead of the base film 10 in the laminated film 50 of the first embodiment.
The base film 10A includes an adhesive layer 16 and an intermediate layer 18 in this order between a barrier layer 14 and an adhesive layer 20. The following mainly describes the differences from the first embodiment.

The adhesive layer 16 is a layer that bonds the barrier layer 14 and the intermediate layer 18 together.
The adhesive layer 16 is made of one or more materials selected from the materials exemplified as the adhesive component of the adhesive layer 20. The adhesive layer 16 may be made of the same material as the adhesive layer 20 in the laminated film 60, or may be made of a different material.
The adhesive layer 16 may or may not contain additive particles.
When the adhesive layer 16 contains additive particles, the laminated film 60 is an example of a film having a plurality of adhesive layers containing additive particles.

When the adhesive layer 16 contains additive particles, the type, content, specific surface area, layer thickness, and average particle size of the additive particles in the adhesive layer 16 are not particularly limited.
For example, it is more preferable that the type, content, specific surface area, layer thickness, and average particle diameter of the additive particles in the adhesive layer 16 be the same type and in the same suitable numerical range as those exemplified for the adhesive layer 20 in the laminated film 50.
The same applies to the type, content, specific surface area, layer thickness, and average particle diameter of the adhesive layer 20 in the laminated film 60 .

When the adhesive layer 16 contains additive particles, the maximum diameter and distribution of the additive particle aggregates in the laminated film 60 are not particularly limited.
It is more preferable that the maximum diameter of the additive particle aggregates in the adhesive layers 20 and 16 in the laminate film 60 is within the preferred range of that in the adhesive layer 20 in the laminate film 50 .
It is more preferable that the distribution of the additive particle aggregates in the laminate film 60 in each of the adhesive layers 20 and 16 in the laminate film 60 be in the preferred range of that in the adhesive layer 20 in the laminate film 50 .

The intermediate layer 18 is a resin layer disposed between the barrier layer 14 and the sealant layer 30. The intermediate layer 18 is adhered to the barrier layer 14 via an adhesive layer 16 and to the sealant layer 30 via an adhesive layer 20.
The material of the intermediate layer 18 is not particularly limited.
The type of intermediate layer 18 can be appropriately selected depending on the application of the laminate film 60. For example, if a resin film excellent in at least one of oxygen barrier properties, water vapor barrier properties, mechanical strength, bending resistance, puncture resistance, impact resistance, abrasion resistance, cold resistance, heat resistance, chemical resistance, and light-blocking resistance is selected, the laminate film 60 will have improved properties.
For example, suitable materials for the intermediate layer 18 include films of nylon, polyethylene terephthalate, polyamide, polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polyvinyl alcohol, ethylene-propylene copolymer, and saponified ethylene-vinyl acetate copolymer, or resin films having a vapor-deposited layer.
For example, by using nylon as the intermediate layer 18, flexibility is improved, and pinholes can be prevented from occurring even when a large external force is applied. Therefore, when a package is formed using a packaging bag using the laminated film 50, pinholes can be prevented from occurring in the laminated film 60, which would cause deterioration of the packaged item. This effect is particularly useful when the packaged item is food.

The laminated film 60 of this embodiment can be manufactured in the same manner as the laminated film 50, except that instead of the base film 10, a base film 10A is formed by laminating an adhesive layer 16 and an intermediate layer 18 on a barrier layer 14.
In particular, when the adhesive layer 16 contains additive particles, the adhesive layer 16 can be manufactured in the same manner as the adhesive layer 20 in the first embodiment.

The laminated film 60 of this embodiment has the same configuration as the laminated film 50 of the first embodiment, except that the adhesive layer 16 and the intermediate layer 18 are laminated between the barrier layer 14 and the adhesive layer 20, and therefore can provide a laminated film that can reduce retort odor and has good laminate strength.
In particular, since the laminated film 60 includes the intermediate layer 18 , the properties of the laminated film 60 can be improved depending on the properties of the intermediate layer 18 .
Furthermore, when the adhesive layer 16 contains polyvalent metal particles or polyvalent metal compound particles, there are two layers that capture odor-causing substances, which can improve the effect of reducing odor-causing substances.

[Third embodiment]
A laminated film according to a third embodiment of the present invention will now be described.
FIG. 3 is a schematic cross-sectional view showing an example of a laminated film according to a third embodiment of the present invention.

The laminate film 70 of this embodiment shown in Figure 3 includes a base film (predetermined layer) 10B instead of the base film 10A in the laminate film 70 of the second embodiment. The laminate film 70 includes a resin layer 12, an adhesive layer 16, an intermediate layer 18, an adhesive layer 16B, and an intermediate layer 18B, which are laminated in this order. The following description will focus on the differences from the second embodiment.

The adhesive layer 16 is a layer that bonds the resin layer 12 and the intermediate layer 18. The adhesive layer 16B is a layer that bonds the intermediate layer 18 and the intermediate layer 18B.
The adhesive layers 16, 16B are made of one or more of the materials exemplified as the adhesive component in the adhesive layer 20. The adhesive layers 16, 16B may be made of the same material as the adhesive layer 20 in the laminated film 70, or may be made of a different material.
The adhesive layers 16 and 16B may or may not contain additive particles.
When the adhesive layers 16 and 16B contain additive particles, the laminated film 70 is an example of a film having a plurality of adhesive layers containing additive particles.

When the adhesive layer 16, 16B contains additive particles, the type, content, specific surface area, layer thickness, and average particle size of the additive particles in the adhesive layer 16, 16B are not particularly limited.
For example, it is more preferable that the type, content, specific surface area, layer thickness, and average particle diameter of the additive particles in adhesive layers 16, 16B be the same type and suitable numerical range as those exemplified for adhesive layer 20 in laminated film 50.
The same applies to the type, content, specific surface area, layer thickness, and average particle diameter of the adhesive layer 20 in the laminated film 70 .

When additive particles are contained in the adhesive layers 16, 16B, the maximum diameter and distribution of the additive particle aggregates in the laminated film 70 are not particularly limited.
It is more preferable that the maximum diameter of the additive particle aggregates in the adhesive layers 16 and 16B in the laminate film 70 is within the preferred range of that of the adhesive layer 20 in the laminate film 50 .
It is more preferable that the distribution of the additive particle aggregates in the laminate film 70 in each of the adhesive layers 16 and 16B in the laminate film 70 be in the preferred range of that in the adhesive layer 20 in the laminate film 50 .

The intermediate layer 18 is a resin layer disposed between the resin layer 12 and the intermediate layer 18B. The intermediate layer 18 is adhered to the resin layer 12 via the adhesive layer 16 and to the intermediate layer 18B via the adhesive layer 16B.
The material of the intermediate layer 18 is not particularly limited.
The type of intermediate layer 18 can be appropriately selected depending on the application of the laminate film 70. For example, if a resin film excellent in at least one of oxygen barrier properties, water vapor barrier properties, mechanical strength, bending resistance, puncture resistance, impact resistance, abrasion resistance, cold resistance, heat resistance, chemical resistance, and light-blocking resistance is selected, the laminate film 70 will have improved properties.
For example, suitable materials for the intermediate layer 18 include films of nylon, polyethylene terephthalate, polyamide, polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polyvinyl alcohol, ethylene-propylene copolymer, and saponified ethylene-vinyl acetate copolymer, or resin films having a vapor-deposited layer.
For example, by using nylon as the intermediate layer 18, flexibility is improved, and the occurrence of pinholes can be suppressed even when a large external force is applied. Therefore, when a package is formed using a packaging bag using the laminated film 70, it is possible to suppress the occurrence of pinholes in the laminated film 70, which would cause deterioration of the packaged item. This effect is particularly useful when the packaged item is food.

The intermediate layer 18B is a layer disposed between the intermediate layer 18 and the sealant layer 30. The intermediate layer 18B is adhered to the intermediate layer 18 via the adhesive layer 16B and to the sealant layer 30 via the adhesive layer 20.
For example, aluminum film foil can be used as the intermediate layers 18, 18B. Aluminum film foil has the properties of being impermeable to gases and liquids and blocking light. Therefore, when a package is formed using a packaging bag using the laminated film 70, deterioration of the packaged item can be suppressed. Furthermore, since it does not allow odors to escape, it can suppress the loss of aroma and deterioration of flavor. This effect is particularly useful when the packaged item is food.

The laminated film 70 of this embodiment can reduce retort odor and provide a laminated film with good laminate strength.

[Fourth embodiment]
A packaging bag and a packaging body according to a fourth embodiment of the present invention will be described.
FIG. 4 is a schematic front view showing an example of a packaging bag and a package according to a fourth embodiment of the present invention.

As shown in FIG. 4 , the packaging body 200 of this embodiment includes the packaging bag 100 of this embodiment and an item 110 to be packaged housed inside the packaging bag 100 .
The packaging bag 100 includes a sealed portion 101 formed by bonding together the peripheral edges of a pair of laminated films 50 cut into a substantially rectangular shape, and a containing portion 102 formed between the pair of laminated films 50 surrounded by the sealed portion 101. That is, the side edges, bottom edge, and top edge of the packaging bag 100 are sealed by the sealed portion 101.
The storage section 102 forms a storage space sandwiched between a pair of laminated films 50 and surrounded by the seal section 101, and stores a packaged item 110 such as food.
For example, the package 200 may be a retort food product in which the packaged item 110 made of food is heat-sterilized and sealed in the packaging bag 100.

The pair of laminated films 50 are formed by cutting the laminated film 50 of the first embodiment to an appropriate size.
The pair of laminated films 50 are overlapped with each other so that the sealant layers 30 face each other. Each sealant layer 30 is heat-sealed at the outer periphery of the pair of laminated films 50. This forms a seal portion 101.

The packaging bag 100 is equipped with opening means 120. For example, the opening means 120 has a pair of easy-to-open processed portions 124 formed in the seal portion 101 at the side end portion, and a half-cut line 121 between the pair of easy-to-open processed portions 124, which serves as a cutting path for opening the bag.
The easy-open processed portion 124 is not particularly limited as long as it has a configuration that allows the packaging bag 100 to be easily opened. For example, the easy-open processed portion 124 may be formed by a group of scars consisting of a collection of fine recesses formed on the surface of the sealed portion 101. For example, the easy-open processed portion 124 may be a notch that penetrates the edge of the sealed portion 101 in the thickness direction. The shape of the notch is not particularly limited, and may be, for example, a V-shaped, U-shaped, I-shaped, or the like notch.
For example, the half-cut line 121 can be formed by laser processing.

A method for manufacturing the packaging bag 100 and the package 200 will be described.
FIG. 5 is a schematic perspective view showing a method for manufacturing a packaging bag according to a fourth embodiment of the present invention.

A pair of laminated films 50 cut to fit the outer shape of the packaging bag 100 are prepared.
Thereafter, as shown in FIG. 5, the sealant layers 30 of the laminated films 50 are placed opposite each other, and the sealant layers 30 at the bottom and side edges of the laminated films 50 are heat-sealed together.
As a result, a seal portion 101 is formed at the bottom end and the side end portions. A storage portion 102 is formed inside each laminate film 50 surrounded by the seal portion 101 in a U-shape.
An opening communicating with the storage section 102 is formed at the upper end of the packaging bag 100 .
Thereafter, the packaged item 110 is filled into the unsealed packaging bag 100 from the upper end thereof. Thereafter, the sealant layers 30 of the laminated films 50 facing each other at the upper end are heat-sealed to form a sealed portion 101 at the upper end as well. In this manner, a package 200 as shown in FIG. 4 can be manufactured.

In the packaging bag 100 of this embodiment, the storage section 102 is formed by the same laminated film 50 as in the first embodiment.
Each laminated film 50 has a barrier layer 14, which prevents oxygen and water vapor from penetrating from the outside to the inside, and prevents deterioration of the components and packaged items 110 inside the barrier layer 14 caused by oxygen and water vapor.
Each laminate film 50 contains polyvalent metal particles or polyvalent metal compound particles in the adhesive layer 20 on the inner side (packaged item side) of the barrier layer 14. This allows the film 50 to adsorb, for a long period of time, substances that cause retort odor, such as sulfur compounds, that are generated from the packaged item 110. This allows the packaging bag 100 to prevent substances that cause retort odor, which accumulate inside the packaged item 110 in the storage section 102, from accumulating on the packaged item 110 within the storage section 102.
As a result, the retort odor that occurs when the package 200 is opened can be reduced.
Depending on the type of packaged item 110, it may contain components (deterioration-causing components) that alter the polyvalent metal particles or polyvalent metal compound particles and deteriorate the retort odor capturing function. For example, acids such as acetic acid contained in various foods tend to alter the polyvalent metal particles or polyvalent metal compound particles.
In this embodiment, the polyvalent metal particles or polyvalent metal compound particles are mixed into the adhesive component and covered with the adhesive component, and therefore, for example, chemical reactions between the polyvalent metal particles or polyvalent metal compound particles and components that cause deterioration are suppressed, and therefore the polyvalent metal particles or polyvalent metal compound particles are less likely to deteriorate.

As described above, the packaging bag 100 and packaging body 200 of this embodiment include the laminate film 50 of the first embodiment, and therefore, like the first embodiment, can provide a packaging bag and packaging body that can reduce retort odor and have good laminate strength. Note that the same effect can be achieved by using the laminate film 60 of the second embodiment or the laminate film 70 of the third embodiment instead of the laminate film 50.

Fifth Embodiment
A packaging bag and a packaging body according to a fifth embodiment of the present invention will be described.
FIG. 6 is a schematic perspective view showing an example of a packaging bag and a package according to a fifth embodiment of the present invention.

As shown in FIG. 6, a packaging body 210 of this embodiment includes a packaging bag 150 and an article 110 to be packaged, which is the same as that of the fourth embodiment.
The packaging bag 150 is a standing pouch including a pair of laminate films 50 and a bottom tape adhered to the lower end of each laminate film 50. The bottom tape 152 is made of a laminate film having the same layer structure as the laminate film 50.

The packaging bag 150 and packaging body 210 of this embodiment are configured in the same manner as the packaging bag 100 and packaging body 200 of the fourth embodiment, except that they are formed into the shape of a standing pouch by including a bottom tape 152.
The packaging body 210 can be manufactured by manufacturing a packaging bag 150 with an opening at the top end using a well-known standing pouch manufacturing method using a pair of laminated films 50 and a bottom tape 152, then filling the top end with the packaged item 110 and sealing the top end to form the sealed portion 101.

The packaging bag 150 and packaging body 210 of this embodiment include a laminate film 50, just like the fourth embodiment, and therefore have the same effect as the fourth embodiment. Note that the same effect can be achieved even if the laminate film 60 of the second embodiment or the laminate film 70 of the third embodiment is used instead of the laminate film 50.

In the above-described embodiments, the laminated films 50 and 60 are entirely light-transmitting portions.
However, a light-transmitting portion may be formed in part of the laminated films 50, 60 by providing a printed layer in an appropriate portion of the laminated films 50, 60 to form a light-shielding portion in part of the laminated films 50, 60.
For example, when the packaging bag 100 is formed by a pair of laminated films 50 as in the fourth embodiment, one or both of the pair of laminated films 50 may be formed with a light-shielding portion made of a printed layer.
For example, in the laminated films 50 and 60 , the printed layer may be provided between the resin layer 12 and the barrier layer 14 .
The printing layer is a layer composed of ink made by adding various pigments, plasticizers, desiccants, stabilizers, etc. to a binder resin such as a urethane-based, acrylic-based, nitrocellulose-based, or rubber-based resin. This printing layer can display characters, pictures, etc. As the printing method, known printing methods such as offset printing, gravure printing, flexographic printing, silk screen printing, and inkjet printing can be used.
The surface 12b of the resin layer 12 on which the printed layer is formed may be subjected to a corona treatment or ozone treatment as a pretreatment in advance, in order to improve the adhesion between the printed layer and the resin layer 12.

The layer configuration of the laminate film in the first and second embodiments is an example. For example, the laminate film may have any layer or thin film between the adhesive layer 20 and the sealant layer 30, or between the resin layer 12 and the barrier layer 14, as long as the functionality of the laminate film is not significantly impaired.

In the above description of the second embodiment, an example was described in which polyvalent metal particles or polyvalent metal compound particles are contained in the adhesive layer 20 of the laminate film 60, and an example was described in which polyvalent metal particles or polyvalent metal compound particles are contained in both the adhesive layers 20 and 16 of the laminate film 60. However, the polyvalent metal particles or polyvalent metal compound particles may also be contained only in the adhesive layer 16.

In the above description of the second embodiment, an example was described in which there was one intermediate layer. However, the laminated film may include two or more intermediate layers.

The resin layer 12, the adhesive layer 16, the intermediate layer 18, the adhesive layer 16, the aluminum-containing barrier layer 14, the adhesive layer 20, and the sealant layer 30 may be laminated in this order.
The resin layer 12, the adhesive layer 16, the aluminum-containing barrier layer 14, the adhesive layer 20, and the sealant layer 30 may be laminated in this order.
The barrier layer 14, adhesive layer 16, intermediate layer 18, adhesive layer 20, and sealant layer 30 may be laminated in this order.
The resin layer 12, the adhesive layer 16, the intermediate layer 18, the adhesive layer 20, and the sealant layer 30 may be laminated in this order.
The intermediate layer 18, the adhesive layer 20, and the sealant layer 30 may be laminated in this order.
The resin layer 12, the adhesive layer 20, and the sealant layer 30 may be laminated in this order.
The intermediate layer 18, the barrier layer 14, the adhesive layer 20, and the sealant layer 30 may be laminated in this order.

The sealant layer 30 may have the same configuration as the resin layer 12.

The light-blocking property may be imparted by light-blocking printing.
The solid print layer may be provided on the resin layer 12 or the barrier layer 14. For example, when the resin layer 12, the adhesive layer 16, the intermediate layer 18, the adhesive layer 20, and the sealant layer 30 are laminated in this order, the solid print layer provided on the resin layer 12 is disposed between the resin layer 12 and the adhesive layer 16.
For example, when the resin layer 12, the barrier layer 14, the adhesive layer 16, the intermediate layer 18, the adhesive layer 20, and the sealant layer 30 are laminated in this order, the solid print layer provided on the barrier layer 14 is positioned between the barrier layer 14 and the adhesive layer 16.

In the fourth embodiment, an example has been described in which the packaging bag 100 and the packaging body 200 are formed using a pair of laminated films 50 .
However, as shown in FIGS. 4 and 5, instead of the pair of laminated films 50, a pair of laminated films 60, 70 may be used to form the packaging bag 100A and the package 200A.
The packaging bag 100A and the packaging body 200A can be manufactured in the same manner as the packaging bag 100 and the packaging body 200, except that a pair of laminated films 60 is used instead of the pair of laminated films 50.
The packaging bag 100A and the package 200A include a pair of laminated films 60, and therefore have the same function as the laminated film 60.

In the fourth embodiment, an example has been described in which the packaging bag 150 and the packaging body 210 are formed using a pair of laminated films 50 .
However, as shown in FIG. 6, instead of the pair of laminated films 50, a pair of laminated films 60, 70 may be used to form a packaging bag 150A and a packaging body 210A.
The packaging bag 150A and the packaging body 210A can be manufactured in the same manner as the packaging bag 150 and the packaging body 210, except that a pair of laminated films 60 is used instead of the pair of laminated films 50.
The packaging bag 150A and the packaging body 210A include a pair of laminated films 60, and therefore have the same function as the laminated film 60.

In the fourth and fifth embodiments, examples have been described in which a packaging bag and a packaging body are formed using a pair of laminate films 50. However, as long as the laminate film 50 is used in a portion of the outer periphery of the packaging bag and the packaging body, the laminate film in the other outer periphery may have a layer structure different from that of the laminate film 50.
For example, if the retort odor can be suppressed by the polyvalent metal particles or polyvalent metal compound particles contained in one laminate film 50, the other laminate films do not need to contain polyvalent metal particles or polyvalent metal compound particles.

In the fourth and fifth embodiments described above, the packaging bag has been described as a four-sided bag and a standing pouch, but the shape of the packaging bag is not limited to these and may have other well-known bag shapes.
For example, the shape of the packaging bag may be a two-sided bag, a three-sided bag, or a palm-shaped bag.
For example, the packaging bag may be provided with a synthetic resin zipper that can be repeatedly sealed by fitting a stopper or a strip-shaped protrusion into a strip-shaped groove.

The packaging bag may have one or more functions, such as retort packaging, boiling packaging, or microwave packaging.

In the fourth and fifth embodiments described above, the packaged item 110 was described as a food product, but the packaged item 110 is not limited to food products.

The packaged item 110 may be curry, oden, noodle soup, seasoning, pasta sauce, side dish, soup, rice pot mix, or pet food.

Next, Examples 1 to 31 of the present invention will be described together with Comparative Examples 1 to 20. The configurations of Examples 1 to 22 and Comparative Examples 1 to 14 correspond to the second embodiment of the present invention. The configurations of Examples 23 to 31 and Comparative Examples 15 to 20 correspond to the third embodiment of the present invention.
First, a summary will be given of the particle dispersions used in the production of the laminate films of Examples 1 to 31 and Comparative Examples 1 to 20. Each particle dispersion was used to produce an adhesive containing polyvalent metal compound particles.
The compositions of the particle dispersions and the dispersion treatments used in producing the laminated films of Examples 1 to 31 and Comparative Examples 1 to 20 are shown in Table 1 below.

[Particle dispersion liquid 11Aa]
As shown in Table 1, particle dispersion liquid 11Aa was prepared by dispersing fine particles of zinc oxide (ZnO), which is a polyvalent metal oxide (hereinafter referred to as zinc oxide particles), in ethyl acetate.
Particle dispersion 11Aa was prepared as follows.
First, zinc oxide particles were added to ethyl acetate as a solvent to form a mixed solution. FINEX-30 (trade name; manufactured by Sakai Chemical Industry Co., Ltd.) with an average particle size of 35 nm was used as the zinc oxide particles. The amount of FINEX (registered trademark)-30 added was such that the solids concentration of the mixed solution became 30% by mass.
Thereafter, a dispersant A containing a polyester acid amidoamine salt, an alkylcyclohexane, and propylene glycol monomethyl ether acetate was added to the mixture. Dispersant A is a dispersant whose main component is an amidoamine acid, which is a high molecular weight polyester acid.
The amount of dispersant A added was 5 parts by mass, assuming that the solid content of the zinc oxide particles in the mixed liquid was 100 parts by mass.
This mixture was subjected to a dispersion treatment using a planetary ball mill (described as "bead mill" in Table 1).
As a result, a particle dispersion liquid 11Aa in which zinc oxide particles were dispersed in a solvent was prepared.

[Particle dispersion liquid 11Ba]
Particle dispersion liquid 11Ba was prepared in the same manner as particle dispersion liquid 11Aa, except that the amount of dispersant added was 40 parts by mass.

[Particle dispersion liquid 11Ca]
Particle dispersion liquid 11Ca was prepared in the same manner as particle dispersion liquid 11Aa, except that the amount of dispersant added was 20 parts by mass.

[Particle dispersion liquid 12Aa, 12Ba]
Particle dispersion 12Aa was prepared in the same manner as particle dispersion 11Aa, except that dispersant B containing a phosphate ester was used instead of dispersant A. Dispersant B is a polyether phosphate ester compound-based dispersant.
Particle dispersion liquid 12Ba was prepared in the same manner as particle dispersion liquid 12Aa, except that the amount of dispersant added was 40 parts by mass.

[Particle dispersion liquid 13Aa, 13Ba]
Particle dispersion 13Aa was prepared in the same manner as particle dispersion 11Aa, except that dispersant C, which contained a vinyl chloride-vinyl acetate copolymer, acetone, and methanol, was used instead of dispersant A. Dispersant C is a dispersant whose main component is a vinyl chloride-vinyl acetate copolymer resin.
Particle dispersion liquid 13Ba was prepared in the same manner as particle dispersion liquid 13Aa, except that the amount of dispersant added was 40 parts by mass.

[Particle dispersion liquid 14Aa, 14Ba, 14Ca]
Particle dispersion 14Aa was prepared in the same manner as particle dispersion 11Aa, except that FINEX (registered trademark)-50 (trade name; manufactured by Sakai Chemical Industry Co., Ltd.), which are zinc oxide particles having an average primary particle diameter of 20 nm, was used instead of FINEX-30 (registered trademark) having an average primary particle diameter of 35 nm.
Particle dispersion liquid 14Ba was prepared in the same manner as particle dispersion liquid 14Aa, except that the amount of dispersant added was 40 parts by mass.
Particle dispersion liquid 14Ca was prepared in the same manner as particle dispersion liquid 14Aa, except that the amount of dispersant added was 20 parts by mass.

[Particle dispersion liquid 15Aa, 15Ba]
Particle dispersion 15Aa was prepared in the same manner as particle dispersion 11Aa, except that FINEX (registered trademark)-20, which is zinc oxide particles having an average particle size of 60 nm as primary particles, was used instead of FINEX (registered trademark)-30.
Particle dispersion liquid 15Ba was prepared in the same manner as particle dispersion liquid 15Aa, except that the amount of dispersant added was 40 parts by mass.

[Particle dispersions 100a, 200a, 300a, and 400a]
Particle dispersion 100a was prepared in the same manner as particle dispersion 11Aa, except that no dispersant was added.
Particle dispersion 200a was prepared in the same manner as particle dispersion 100a, except that aluminum oxide (AlO) particles (hereinafter referred to as aluminum oxide particles) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. were used instead of zinc oxide particles. The average particle diameter of the aluminum oxide particles was 45 nm.
Particle dispersion 300a was prepared in the same manner as particle dispersion 100a, except that magnesium oxide (MgO) particles (hereinafter referred to as magnesium oxide particles) manufactured by Stream Chemicals were used instead of zinc oxide particles. The magnesium oxide particles had an average particle size of 20 nm.
Particle dispersion 400a was prepared in the same manner as particle dispersion 100a, except that FINEX®-50 was used instead of FINEX®-30.

[Particle dispersion liquid 11Ab, 11Bb, 11Cb]
Particle dispersion liquid 11Ab was prepared in the same manner as particle dispersion liquid 11Aa, except that the dispersion treatment using a planetary ball mill was not performed and the mixed liquid was stirred for 10 minutes using a stirring blade (described as "stirring only" in [Table 1]).
Particle dispersion liquid 11Bb was prepared in the same manner as particle dispersion liquid 11Ab, except that the amount of dispersant added was 40 parts by mass.
Particle dispersion liquid 11Cb was prepared in the same manner as particle dispersion liquid 11Ab, except that the amount of dispersant added was 20 parts by mass.

[Particle dispersion liquid 14Ab, 14Bb]
Particle dispersion 14Ab was prepared in the same manner as particle dispersion 14Aa, except that the dispersion treatment using a planetary ball mill was not carried out and the mixture was stirred for 10 minutes using a stirring blade.
Particle dispersion liquid 14Bb was prepared in the same manner as particle dispersion liquid 14Ab, except that the amount of dispersant added was 40 parts by mass.

[Particle dispersion liquid 100b, 200b, 300b, 400b]
Particle dispersion 100b was prepared in the same manner as particle dispersion 100a, except that the dispersion treatment using a planetary ball mill was not carried out and the mixture was stirred for 10 minutes using a stirring blade.
Particle dispersion liquid 200b was prepared in the same manner as particle dispersion liquid 200a, except that the dispersion treatment using a planetary ball mill was not performed and the mixture was stirred for 10 minutes using a stirring blade.
Particle dispersion 300b was prepared in the same manner as particle dispersion 300a, except that the dispersion treatment using a planetary ball mill was not performed and the mixture was stirred for 10 minutes using a stirring blade.
Particle dispersion 400b was prepared in the same manner as particle dispersion 400a, except that the dispersion treatment using a planetary ball mill was not carried out and the mixture was stirred for 10 minutes using a stirring blade.

Table 2 below shows the manufacturing conditions and evaluation results for Examples 1 to 31 and Comparative Examples 1 to 20.

[Example 1]
In Example 1, Toyobo Ester (registered trademark) film E5100 (product name; manufactured by Toyobo Co., Ltd.), which is a biaxially stretched polyethylene terephthalate film, was used as the resin layer 12. The E5100 had a thickness of 12 μm, a length of 500 m, and a width of 600 mm.
One surface 12b of the resin layer 12 was subjected to a corona treatment, and a barrier layer 14 made of SiOx was formed on the corona-treated surface 12b using a vacuum deposition machine.
Specifically, a deposition material containing a mixture of metal silicon powder and silicon dioxide powder was prepared, and deposition was performed using a vacuum deposition machine to form a deposition layer on the surface 12b with an element ratio of O/Si of 1.5 (x = 1.5). The barrier layer 14 had a thickness of 50 nm.
Thereafter, a two-component curing polyurethane adhesive A626/A50 (product name: manufactured by Mitsui Chemicals, Inc.) was applied onto the barrier layer 14 using a dry lamination machine, and a 15 μm-thick nylon film, Emblem (registered trademark) ON (product name: manufactured by Unitika Ltd.), was laminated thereon, thereby forming an adhesive layer 16 and an intermediate layer 18.

Using the particle dispersion liquid 11Aa, a coating liquid for forming the adhesive layer 20 was prepared as follows.
The two-component curing polyurethane adhesives A626 and A50 were mixed at a mass ratio of 8:1 and diluted with ethyl acetate to form an adhesive with a solids concentration of 30 mass%. Particle dispersion 11Aa was then added to the adhesive, and the ratio of the solids of the zinc oxide particles to the total mass of the solids of the adhesive and the zinc oxide particles was adjusted to 1.5 mass%.
For simplicity, the "ratio of the solid content of the polyvalent metal compound particles to the total mass of the solid content of the adhesive and the solid content of the polyvalent metal compound particles" will be referred to as the "particle amount in the coating liquid." In Table 2, this is referred to as the "particle amount."
Thereafter, the mixture of the adhesive and the particle dispersion liquid 11Aa was stirred for 30 minutes using a stirring blade. Thereafter, the mixture was filtered through a membrane filter with a pore size of 3 μm to obtain the coating liquid 11Aa used in Example 1. Since the zinc oxide particles were less likely to aggregate in the particle dispersion liquid 11Aa that had been subjected to the dispersion treatment, most of the zinc oxide particles in the mixture passed through the membrane filter.

Thereafter, the coating liquid 11Aa was applied onto the intermediate layer 18 using a dry lamination machine, and the resulting sealant layer 30 was laminated with a polyolefin-based unstretched co-extruded film having a thickness of 80 μm.
In this way, a laminated film 60 having the laminated structure shown in Fig. 2 was obtained. That is, this laminated film 60 had, in this order, a sealant layer 30 made of a polyolefin-based unstretched co-extruded film, an adhesive layer 20 containing zinc oxide particles, an intermediate layer 18 made of a nylon film, an adhesive layer 16 not containing zinc oxide particles, a barrier layer 14, and a resin layer 12.
The amount of zinc oxide particles in the adhesive layer 20 was 1.5% by mass, the same as the amount of particles in the coating liquid.

Thereafter, the laminated film 60 of Example 1 was attached so that the sealant layers 30 faced each other, thereby producing the packaging bag 100A of Example 1, which was a three-sided bag as shown in FIG.
Thereafter, the packaged item 110 was placed in the packaging bag 100A and sealed, thereby producing the package 200A of Example 1.
The packaged item 110 used was an aqueous cysteine solution containing 0.03% by mass of cysteine.

[Examples 2 to 22]
As shown in Table 2, in Examples 2 to 22, the laminated film 60, packaging bag 100A, and packaging body 200A were produced in the same manner as in Example 1, except that the coating liquid shown in each column was used instead of coating liquid 11Aa.
The particle amount of zinc oxide particles in coating liquid 11Aa is 1.5 mass%, while the particle amount of zinc oxide particles in coating liquid 11Aa+ is 9.5 mass%, the particle amount of zinc oxide particles in coating liquid 11Aa- is 0.8 mass%, and the particle amount of zinc oxide particles in coating liquid 11Aa++ is 11 mass%.
The particle amount of zinc oxide particles in Coating Liquid 11Ca is 3.0% by mass, whereas the particle amount of zinc oxide particles in Coating Liquid 11Ca+ is 5.0% by mass.
The particle amount of zinc oxide particles in Coating Liquid 14Ca is 3.0% by mass, whereas the particle amount of zinc oxide particles in Coating Liquid 14Ca+ is 5.0% by mass.
The particle amount of zinc oxide particles in Coating Liquid 100a is 1.5% by mass, whereas the particle amount of zinc oxide particles in Coating Liquid 100a+ is 9.5% by mass.

[Example 23]
In Example 23, Toyobo Ester (registered trademark) film E5100 (product name; manufactured by Toyobo Co., Ltd.), which is a biaxially stretched polyethylene terephthalate film, was used as the resin layer 12. E5100 had a thickness of 12 μm, a length of 500 m, and a width of 600 mm.
A two-component curing polyurethane adhesive A525/A52 (trade name: manufactured by Mitsui Chemicals, Inc.) was applied onto the resin layer 12 using a dry lamination machine, and a 15 μm thick nylon film, Emblem (registered trademark) ON (trade name: manufactured by Unitika Ltd.), was laminated on top of the resin layer 12 as an intermediate layer 18. In this way, an adhesive layer 16 and an intermediate layer 18 were formed.

Next, adhesive was applied again to the intermediate layer 18 in the same manner, and a 7 μm thick aluminum film foil was laminated on top as intermediate layer 18B. This formed adhesive layer 16B and intermediate layer 18B.

Using the particle dispersion liquid 11Aa, a coating liquid for forming the adhesive layer 20 was prepared as follows.
The two-component curing polyurethane adhesives A525 and A52 were mixed at a mass ratio of 8:1 and diluted with ethyl acetate to form an adhesive with a solids concentration of 30 mass %. Particle dispersion 11Aa was then added to the adhesive, and the ratio of the solids of the zinc oxide particles to the total mass of the solids of the adhesive and the zinc oxide particles was adjusted to 1.5 mass %.
For simplicity, the "ratio of the solid content of the polyvalent metal compound particles to the total mass of the solid content of the adhesive and the solid content of the polyvalent metal compound particles" will be referred to as the "particle amount in the coating liquid." In Table 2, this is referred to as the "particle amount."
Thereafter, the mixture of the adhesive and the particle dispersion 11Aa was stirred for 30 minutes using a stirring blade. Thereafter, the mixture was filtered through a membrane filter with a pore size of 3 μm to obtain Coating Solution 11Aa used in Example 19. Since the zinc oxide particles were less likely to aggregate in the particle dispersion 11Aa that had been subjected to the dispersion treatment, most of the zinc oxide particles in the mixture passed through the membrane filter.

Thereafter, the coating liquid 11Aa was applied onto the intermediate layer 18B using a dry lamination machine, and the resulting film was laminated with a polyolefin-based unstretched co-extruded film having a thickness of 80 μm to form a sealant layer 30.
In this way, a laminated film 70 having the laminated structure shown in Fig. 3 was obtained. That is, this laminated film 70 had, in this order, a sealant layer 30 made of a polyolefin-based unstretched co-extruded film, an adhesive layer 20 containing zinc oxide particles, an intermediate layer 18B made of aluminum foil, an adhesive layer 16B not containing zinc oxide particles, an intermediate layer 18 made of a nylon film, an adhesive layer 16 not containing zinc oxide particles, and a resin layer 12.
The amount of zinc oxide particles in the adhesive layer 20 was 1.5% by mass, the same as the amount of particles in the coating liquid.

Thereafter, the laminated film 70 of Example 1 was attached so that the sealant layers 30 faced each other, thereby producing the packaging bag 100A of Example 1, which was a three-sided bag as shown in FIG.
Thereafter, the packaged item 110 was placed in the packaging bag 100A and sealed, thereby producing the package 200A of Example 1.
The packaged item 110 used was an aqueous cysteine solution containing 0.03% by mass of cysteine.

[Examples 24 to 31]
As shown in Table 2, in Examples 24 to 31, the laminated film 70, packaging bag 100A, and packaging body 200A were produced in the same manner as in Example 23, except that the coating liquid shown in each column was used instead of coating liquid 11Aa.

[Comparative Examples 1 to 14]
In Comparative Example 1, the laminated film 60, packaging bag 100A, and packaging body 200A of Comparative Example 1 were produced in the same manner as in Example 1, except that the adhesive layer was formed using only a polyurethane-based adhesive without using polyvalent metal particles or polyvalent metal compound particles.
In Comparative Example 2, except that Coating Liquid 100bN (particle amount of zinc oxide particles: 1.5 mass%) was used instead of Coating Liquid 100a, a laminated film 60, a packaging bag 100A, and a package 200A of Comparative Example 2 were produced in the same manner as in Example 9. Coating Liquid 100bN was formed in the same manner as Coating Liquid 100a, except that the adhesive and particle dispersion liquid 100b were stirred for 30 minutes and then not filtered with a membrane filter.
In Comparative Examples 3 to 14, the same stirring process as in Comparative Example 2 was carried out except that the coating liquids described in the respective columns were used, and the laminated film 60, packaging bag 100A, and packaging body 200A were produced.
The particle amount of zinc oxide particles in coating liquid 100bN is 1.5 mass%, while the particle amount of zinc oxide particles in coating liquid 100bP is 3.0 mass%, and the particle amount of zinc oxide particles in coating liquid 100b+ is 9.5 mass%.
The particle amount of aluminum oxide particles in coating liquid 200b is 1.5 mass %, whereas the particle amount of aluminum oxide particles in coating liquid 200b+ is 9.5 mass %.
The particle amount of magnesium oxide particles in coating liquid 300b is 1.5 mass %, whereas the particle amount of magnesium oxide particles in coating liquid 300b+ is 9.5 mass %.

[Comparative Examples 15 to 20]
In Comparative Example 15, the laminated film 70, packaging bag 100A, and package 200A of Comparative Example 16 were produced in the same manner as in Example 23, except that coating solution 11Ab (particle amount of zinc oxide particles: 1.5 mass%) was used instead of coating solution 11Aa. Coating solution 11Ab was formed in the same manner as coating solution 11Aa, except that the adhesive and particle dispersion solution 11Ab were stirred for 30 minutes and then not filtered with a membrane filter.
In Comparative Examples 16 to 20, the stirring treatment was carried out in the same manner as in Example 23, except that the coating liquids described in the respective columns were used, and laminated films 70, packaging bags 100A, and packaging bodies 200A were produced.

[Evaluation method]
To evaluate each example and each comparative example, SEM images were observed, and hydrogen sulfide (H ₂ S) concentration and laminate strength were measured.

For SEM image observation results, the laminated film was cut with a microtome and the cross section was observed with an SEM. Five consecutive 10 μm images were taken along the adhesive layer 20 at 10,000x magnification. The maximum length (maximum diameter of the aggregate) of the diameters (major axis) of the aggregates contained in the five images was recorded in the "Maximum Aggregate Diameter" column of Table 2. The minimum length (minimum diameter of the aggregate) of the diameters of the aggregates contained in the five images was recorded in the "Minimum Aggregate Diameter" column of Table 2. The "maximum diameter of the aggregate" divided by the "minimum diameter of the aggregate" (magnification of the maximum diameter of the aggregate relative to the minimum diameter of the aggregate) was recorded in the "Magnification" column of Table 2. The sum of all the diameters (major axis) of the aggregates contained in the five images was divided by the number of aggregates (average aggregate diameter of the aggregates) and recorded in the "Average Aggregate Diameter" column of Table 2. Of the aggregates contained in the five photographs, the number of aggregates with a size that is 10 to 200% of the average particle diameter is recorded in the "Number of Aggregates 1" column of [Table 2]. Of the aggregates contained in the five photographs, the number of aggregates with a diameter (major axis) of 3 μm or more is recorded in the "Number of Aggregates 2" column of [Table 2]. For aggregates contained in the five photographs that have a diameter similar to the average aggregate diameter (10% to 200% of the average aggregate diameter), the average value of the distance between adjacent aggregates is recorded in the "Distance between Aggregates" column of [Table 2].

For measuring the concentration of hydrogen sulfide, the packages containing the aqueous cysteine solutions of the examples and comparative examples were used as test samples.
The packages of each test sample were subjected to a retort treatment by heating at 120°C for 60 minutes. After the retort treatment, the packages were stored in a refrigerator for one week. After this, the aqueous solution in each package was sampled, and the hydrogen sulfide concentration was determined by the methylene blue method (wavelength: 668 nm). A calibration curve prepared in advance was used to calculate the hydrogen sulfide concentration. The measurement results of the hydrogen sulfide concentration are shown in Table 2.

The test samples used for measuring the laminate strength were packaging bags corresponding to the respective Examples and Comparative Examples before the retort treatment and packaging bags after the retort treatment.
The corresponding packaging bags before retort treatment were aged at 45°C for 4 days. After this, the laminate strength between the nylon layer and the sealant layer was measured in accordance with JIS Z 0238:1998. Specifically, the laminate strength of each test sample was measured using a Tensilon universal material testing machine (trade name; manufactured by A&D Co., Ltd.) by the T-peel method (crosshead speed: 300 mm/min). The measurement results are shown in the "Laminate strength before treatment" column in Table 2.
Using test samples of packaging bags after retort treatment, the laminate strength (N/15 mm width) was measured in the same manner as for the corresponding packaging bags before retort treatment. The measurement results are shown in the "Laminate Strength After Treatment" column in Table 2. However, in Table 2, (N/15 mm width) is simply expressed as (N).

[Evaluation results]
As shown in Table 2, in the laminate films of Examples 1 to 31, the "magnification" in the adhesive layer 20 was 2.86 to 13.33. The "average aggregate diameter" was 25 nm to 110 nm. The "number of aggregates 1" was 60 to 5,000, and the "number of aggregates 2" was 0. The "distance between aggregates" was 0.3 to 2.7 μm.

Furthermore, the laminate films of Examples 1 to 19 and 21 to 30 had a laminate strength of 8 N/15 mm width or more after retort treatment. Furthermore, the laminate films of Examples 20 and 31 had a laminate strength of 6 N/15 mm width or more after retort treatment.

In Examples 1 to 31, the "magnification ratio" was 2.86 to 13.33. In Comparative Examples 2 to 20, the "magnification ratio" was 77.78 to 180.00. In Comparative Examples 2 to 20, the results were poor in both the retort odor adsorption effect and the laminate strength after retort processing. Therefore, it can be seen that a "magnification ratio" of 14.0 times or less improves the retort odor adsorption effect while also improving the laminate strength after retort processing. This is thought to be because in Examples 1 to 31, there are no large agglomerates, so large interfaces are not formed, and therefore the laminate strength is less likely to deteriorate.

In Examples 1 to 31, the "average aggregate diameter" was 25 nm to 110 nm. In Comparative Examples 2 to 20, the "average aggregate diameter" was 2000 nm (2.0 μm) to 3500 nm (3.5 μm). In Comparative Examples 2 to 20, the results were poor in both the retort odor adsorption effect and the laminate strength after retort treatment. Since a smaller aggregate diameter increases the surface area and improves the adsorption effect, it can be seen that an "average aggregate diameter" of 150 nm or less improves the retort odor adsorption effect and also improves the laminate strength after retort treatment.

In Examples 1 to 31, the "inter-aggregate distance" was 0.3 μm to 2.7 μm. In Comparative Examples 2 to 20, the "inter-aggregate distance" was 15 μm to 40 μm. In Comparative Examples 2 to 20, the results were poor in both the retort odor adsorption effect and the laminate strength after retort processing. When the inter-aggregate distance was small, the number of agglomerates was large. In other words, the size of each agglomerate was small, which increased the surface area, enhanced the adsorption effect, and prevented the formation of large interfaces, making it less likely for laminate strength to deteriorate. Therefore, it was found that an "inter-aggregate distance" of 3.0 μm or less improved the retort odor adsorption effect and achieved good laminate strength after retort processing.

Comparing Example 1, Example 19, and Example 20, the "number of aggregates 1" in Example 20, which has a particle amount of 11% by mass, is 500, the "number of aggregates 1" in Example 1, which has a particle amount of 1.5% by mass, is 80, and the "number of aggregates 1" in Example 19, which has a particle amount of 0.8% by mass, is 65. Comparing Example 2 and Example 3, the "number of aggregates 1" in Example 3, which has a particle amount of 5.0% by mass, is 250, and the "number of aggregates 1" in Example 2, which has a particle amount of 3.0% by mass, is 150. Comparing Example 9 and Example 11, the "number of aggregates 1" in Example 11, which has a particle amount of 9.5% by mass, is 200, and the "number of aggregates 1" in Example 9, which has a particle amount of 1.5% by mass, is 60. Comparing Example 13 and Example 14, the "number of aggregates 1" in Example 14, in which the particle amount is 5.0% by mass, is 300, while the "number of aggregates 1" in Example 13, in which the particle amount is 3.0% by mass, is 200.
That is, it can be seen that the greater the amount of additive particles, the greater the number of "aggregate number 1".

In Examples 1 to 31, the "aggregate number 1," which is the number of aggregates having a size that is 10 to 200% of the average particle size, was 60 or more, whereas in Comparative Examples 1 to 20, the maximum was 0 to 10. When the "aggregate number 1" was 60 or more, dispersibility was increased and retort odor was more easily adsorbed.
That is, it is considered preferable that there are 60 or more aggregates each having a size of 10 to 200% of the average particle size.

In Examples 1 to 31, the "number of aggregates 2," which is the number of aggregates with a diameter (major axis) of 3 μm or more, was 0, whereas in Comparative Examples 1 to 20, the number of "number of aggregates 2" was at least 0 to 2. If no aggregates with a diameter (major axis) of 3 μm or more were present, the cohesive strength of the adhesive layer film was unlikely to decrease.
That is, it is considered preferable that no aggregates having a diameter (major axis) of 3 μm or more exist.

Comparing Example 1, Example 19, and Example 20, the hydrogen sulfide concentration in Example 20, which has a particle amount of 11 mass%, is 0.0 mg/L, the hydrogen sulfide concentration in Example 1, which has a particle amount of 1.5 mass%, is 0.03 mg/L, and the hydrogen sulfide concentration in Example 19, which has a particle amount of 0.8 mass%, is 0.2 mg/L. Comparing Example 2 and Example 3, the hydrogen sulfide concentration in Example 3, which has a particle amount of 5.0 mass%, is 0.01 mg/L, and the hydrogen sulfide concentration in Example 2, which has a particle amount of 3.0 mass%, is 0.02 mg/L. Comparing Example 9 and Example 11, the hydrogen sulfide concentration in Example 11, which has a particle amount of 9.5 mass%, is 0.01 mg/L, and the hydrogen sulfide concentration in Example 9, which has a particle amount of 1.5 mass%, is 0.03 mg/L. Comparing Example 13 and Example 14, the hydrogen sulfide concentration in Example 14, in which the particle amount was 5.0 mass%, was 0.01 mg/L, and the hydrogen sulfide concentration in Example 13, in which the particle amount was 3.0 mass%, was 0.02 mg/L.
That is, it can be seen that the greater the particle amount of additive particles, the greater the adsorption effect on retort odor. A particle amount of 0.5% by mass or more is sufficient to adsorb retort odor, but a particle amount of 1.0% by mass or more is considered preferable.

Comparing Example 1 and Example 20, the laminate strength after retort treatment in Example 1, in which the particle amount is 1.5% by mass, is 8 N/15 mm width, and the laminate strength after retort treatment in Example 20, in which the particle amount is 11% by mass, is 6 N/15 mm width.
In other words, although a larger particle amount of additive particles results in a higher adsorption effect on retort odors, the additive particles are prone to agglomeration, and even if the dispersibility is high, the cohesive strength of the film decreases (the film becomes weaker) as the interface between the adhesive and the particles increases, so it is thought that a particle amount of additive particles of 10 mass% or less is preferable.

Comparing Example 12 with Example 21, the hydrogen sulfide concentration in Example 12, in which the average particle size of the primary particles of the additive particles is 20 nm, is 0.03 mg/L, whereas the hydrogen sulfide concentration in Example 21, in which the average particle size of the primary particles of the additive particles is 60 nm, is 0.06 mg/L. Comparing Example 15 with Example 22, the hydrogen sulfide concentration in Example 15, in which the average particle size of the primary particles of the additive particles is 20 nm, is 0.03 mg/L, whereas the hydrogen sulfide concentration in Example 22, in which the average particle size of the primary particles of the additive particles is 60 nm, is 0.06 mg/L.
That is, although the average particle size of the primary particles of the additive particles may be 60 nm, the surface area decreases as the average particle size increases, so it is considered preferable that the average particle size is 45 nm or less.

Examples 1 and 23, 4 and 24, 9 and 25, 10 and 26, 12 and 27, 15 and 28, 16 and 29, 19 and 30, and 20 and 31 differ in that the former do not contain aluminum film foil in the intermediate layer, while the latter do contain aluminum film foil in the intermediate layer. In all cases, because the reactivity of aluminum is low, similar results were obtained in terms of the retort odor adsorption effect and laminate strength after retort treatment, regardless of the presence or absence of aluminum film foil.

Figure 7 is an example of an SEM image of Example 2. Figure 8 is an example of an SEM image of Comparative Example 5. In Figure 7, P1 indicates an aggregate. In Figure 8, P2 indicates an aggregate, Adhesive 2 indicates the adhesive layer 20, NY indicates the intermediate layer 18, and PP indicates the sealant layer 30.

[comprehensive evaluation]
Regarding retort odor (listed as "Odor" in Table 2), when the hydrogen sulfide concentration was 0.04 mg/L or less, it was judged as good (listed as "A" in Table 2), when the hydrogen sulfide concentration was more than 0.04 mg/L and 0.25 mg/L or less, it was judged as fair (listed as "B" in Table 2), and when it exceeded 0.25 mg/L, it was judged as poor (listed as "C" in Table 2).
Regarding the laminate strength (shown as "Strength" in Table 2), if the laminate strength after retort treatment was 7 N/15 mm width or more, it was judged as good (shown as "A" in Table 2), if the laminate strength after retort treatment was 6 N/15 mm width or more and less than 7 N/15 mm width, it was judged as fair (shown as "B" in Table 2), and if the laminate strength after retort treatment was less than 6 N/15 mm width, it was judged as poor (shown as "C" in Table 2).
As for the overall evaluation, if both the retort odor and the laminate strength were evaluated as good (indicated as "A" in Table 2), the product was judged as good (indicated as "A" in Table 2). If either the retort odor or the laminate strength was evaluated as good (indicated as "A" in Table 2) and the other was evaluated as fair (indicated as "B" in Table 2), the product was judged as fair (indicated as "B" in Table 2). If both the retort odor and the laminate strength were evaluated as fair (indicated as "B" in Table 2), or if either the retort odor or the laminate strength was evaluated as poor (indicated as "C" in Table 2), the product was judged as poor (indicated as "C" in Table 2).

As shown in Table 2, Examples 1 to 18 and 23 to 29 were given an overall rating of A. Examples 19 to 22, 30 and 31 were given an overall rating of B.
Comparative Example 1 received an odor rating of C, and therefore received an overall rating of C.
Comparative Examples 2 to 8 and 12 to 20 were rated B for retort odor and intensity, and therefore received an overall rating of C.
Comparative Examples 9 to 11 were rated C for strength, and therefore received an overall rating of C.

Although the preferred embodiments of the present invention have been described above with reference to the examples, the present invention is not limited to these embodiments and examples. Addition, omission, substitution, and other modifications of the configuration are possible within the scope of the present invention.
Furthermore, the present invention is not limited by the foregoing description, but is limited only by the appended claims.

10, 10A Base film 12 Resin layer 14 Barrier layer 16 Adhesive layer 18 Intermediate layer 20 Adhesive layer 30 Sealant layer 50, 60, 70 Laminated film 100, 100A, 150, 150A Packaging bag 110 Packaged item 200, 200A, 210 Packaged body

Claims (13)

A predetermined layer;
an adhesive layer containing an adhesive component and polyvalent metal particles or polyvalent metal compound particles mixed in the adhesive component;
a sealant layer;
are layered in this order,
the ratio of the maximum diameter of the aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles to the minimum diameter of the aggregates is 14.0 or less;
the adhesive layer contains 0.5% by mass or more and 10% by mass or less of the polyvalent metal particles or the polyvalent metal compound particles,
the average particle size of the polyvalent metal particles or the polyvalent metal compound particles is 5 nm or more and 100 nm or less;
The average aggregate diameter of the aggregates is 150 nm or less.
Laminated film. 2. The laminated film according to claim 1 , wherein the number of said aggregates having a size that is 10 to 200% of the average particle size is 60 or more. There are no agglomerates having a diameter of 3.0 μm or more.
The laminated film according to claim 1 or 2 . For the aggregates having a diameter similar to the average aggregate diameter, the distance between the aggregates, which is the average value of the distances between adjacent aggregates, is 3.0 μm or less.
The laminated film according to any one of claims 1 to 3 . The laminate film according to claim 1 , wherein the predetermined layer is a substrate film having a barrier layer. The base film has a nylon layer.
The laminated film according to claim 5 . The average particle size of the polyvalent metal particles or the polyvalent metal compound particles is 10 nm or more and 45 nm or less.
The laminated film according to any one of claims 1 to 6 . The laminated film according to any one of claims 1 to 7 , wherein the polyvalent metal particles or the polyvalent metal compound particles have a specific surface area of 1 m ² /g or more. The adhesive layer further contains a dispersant that disperses the polyvalent metal particles or the polyvalent metal compound particles in the adhesive component.
The laminated film according to any one of claims 1 to 8 . The laminated film according to claim 1 , wherein the adhesive component is a cured product of a two-component curing adhesive. A packaging bag made by bonding films together,
A packaging bag, wherein the film comprises the laminated film according to any one of claims 1 to 10 . The packaging bag according to claim 11 ;
An item to be packaged to be contained in the packaging bag;
A packaging body comprising: The packaged item contains a sulfur compound.
The package of claim 12 .