Laminated film, packaging bag, package, and method for manufacturing laminated film

Abstract

To provide a laminate film capable of reducing retort smell while having excellent laminate strength and allowing easy visibility of a packaged matter.SOLUTION: A laminate film 50 has a light transmission part allowing a passage of visible light in a thickness direction and includes: a base material film 10 having a barrier layer 14; an adhesion layer 20 containing an adhesive component and polyvalent metal particles or polyvalent metal compound particles mixed with the adhesive component; and a sealant layer 30, laminated in this order. In the light transmission part, a haze measured in accordance with a haze measurement method stipulated in JIS-K-7136 has a ratio of 1.10 or less to a haze measured by the measurement method at the light transmission part with the adhesion layer not containing the polyvalent metal particles and the polyvalent metal compound particles.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laminated film, a packaging bag, a package, and a method for manufacturing a laminated film. [Background technology]

[0002] Packaging materials used to package items are required to have the function of suppressing deterioration of the quality of the packaged items. For example, a packaging bag made by bonding a pair of laminated films is known as a packaging material. Such packaging bags are required to have excellent sealing properties to prevent deterioration of the quality of the packaged items.

[0003] Examples of packaged items include food products. Among food products, meat products, egg products, and other foods containing sulfur-containing amino acids may generate a distinctive odor when sterilized by boiling or retort. This odor is caused by sulfur compounds such as hydrogen sulfide generated by hydrolysis of the sulfur-containing amino acids. Patent Documents 1 and 2 propose providing a layer containing a polyvalent metal compound in a packaging bag to reduce this retort odor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-61682 [Patent Document 2] Japanese Patent Application Publication No. 2017-94533 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-described conventional techniques have the following problems. The packaged items are diverse and contain various components. Certain components may react with the 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 laminated film of Patent Document 2, which includes a layer of zinc oxide particles and an adhesive, is prone to streaks and may not be suitable when transparency and visibility of the packaged contents are required in the laminated film.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a laminated film, a packaging bag, a package, and a method for manufacturing a laminated film that can reduce retort odor, has good laminate strength, and allows the packaged item to be easily viewed. [Means for solving the problem]

[0007] In order to solve the above problems, the laminate film of a first embodiment of the present invention is a laminate film having a light-transmitting portion that transmits visible light in the thickness direction, and comprises a substrate film having a barrier 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, and the haze of the light-transmitting portion measured in accordance with the haze measurement method specified in JIS-K-7136 is 1.10 or less in ratio to the haze of the light-transmitting portion measured by the same measurement method when the adhesive layer does not contain the polyvalent metal particles or the polyvalent metal compound particles.

[0008] In the laminated film, the ratio of the solid content of the polyvalent metal particles or the polyvalent metal compound particles to the total mass of the solid content of the polyvalent metal particles or the polyvalent metal compound particles in the adhesive layer and the solid content of the adhesive may be 0.5 mass% or more and 10 mass% or less.

[0009] In the laminated film, the polyvalent metal particles or the polyvalent metal compound particles may have an average particle size of 10 nm or more and 50 nm or less.

[0010] In the above laminated film, the distribution of aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles in the adhesive layer may be such that the number of aggregates present in a rectangular region of 50 μm in the width direction is 10% or more and 200% or less of the average particle diameter is 50 or more.

[0011] In the laminated film, the average diameter of the aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles in the adhesive layer as viewed in a direction perpendicular to the thickness direction may be 20 nm or more and 120 nm or less.

[0012] In the laminated film, the specific surface area of ​​the polyvalent metal particles or the polyvalent metal compound particles is 1 m 2 / g or more.

[0013] In the laminated film, the adhesive layer may further contain a dispersant that disperses the polyvalent metal particles or the polyvalent metal compound particles in the adhesive component.

[0014] In the laminated film, the adhesive component may be a cured product of a two-component curing adhesive.

[0015] In the laminated film, the maximum diameter of the aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles in the adhesive layer as viewed in a direction perpendicular to the thickness direction may be 1.0 μm or less.

[0016] In the laminated film, the base film may have a nylon layer.

[0017] A packaging bag according to a second aspect of the present invention is a packaging bag formed by laminating films, and the films include the laminated film.

[0018] A packaging body according to a third aspect of the present invention comprises the packaging bag described above and an item to be packaged housed in the packaging bag.

[0019] In the above package, the packaged item may contain a sulfur compound.

[0020] A fourth aspect of the present invention relates to a method for producing a laminated film, which comprises a substrate film having a barrier layer, an adhesive layer containing an adhesive component and polyvalent metal particles or polyvalent metal compound particles mixed in the adhesive component, and a sealant layer laminated in this order, and which has a light-transmitting portion through which visible light transmits in the thickness direction, wherein the haze of the light-transmitting portion measured in accordance with the haze measurement method specified in JIS-K-7136 is a ratio of 1.10 or less to the haze of the light-transmitting portion measured by the same measurement method when the adhesive layer does not contain the polyvalent metal particles or the polyvalent metal compound particles, and the step of forming the adhesive layer comprises: The method includes a coating liquid preparation step of preparing a coating liquid by mixing the polyvalent metal particles or the polyvalent metal compound particles with an adhesive that forms the adhesive component after curing, and in the coating liquid preparation step, a dispersion treatment is performed using a bead mill while the polyvalent metal particles or the polyvalent metal compound particles, a dispersant, and a solvent are mixed together. [Effects of the Invention]

[0021] According to the laminated film, packaging bag, package, and method for producing a laminated film of the present invention, the packaged item can be easily seen. In addition, the laminate film, packaging bag, package, and method for producing the laminate film of the present invention can reduce retort odor and improve laminate strength. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic cross-sectional view showing an example of a laminated film according to a first embodiment of the present invention. [Figure 2] FIG. 4 is a schematic cross-sectional view showing an example of a laminated film according to a second embodiment of the present invention. [Figure 3] It is a schematic front view showing an example of a packaging bag and a package according to the third embodiment of the present invention. [Figure 4] It is a schematic perspective view showing a manufacturing method of a packaging bag according to the third embodiment of the present invention. [Figure 5] It is a schematic perspective view showing an example of a packaging bag and a package according to the fourth embodiment of the present invention. [Figure 6] It is an example of a photographic image of the laminated film of Example 2. [Figure 7] It is an example of a photographic image of the laminated film of Comparative Example 5.

Mode for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common descriptions are omitted. The positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings unless otherwise specified. Hereinafter, when a plurality of suitable numerical ranges are exemplified under a specific numerical range, unless otherwise specified, the combination of the upper limit value and the lower limit value is not limited to the exemplified combinations as long as it is included in the preferable maximum numerical range. For example, assuming x1 < x2 < x3 < x4, and the preferable ranges of the quantity X are exemplified as "x1 or more and x4 or less" and "x2 or more and x3 or less", then numerical ranges such as "exceeding x1 and less than x4", "x2 or more and x4 or less", "x3 or more and x4 or less", etc. are also preferable ranges.

[0024] [First Embodiment] The laminated film according to the first embodiment of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing an example of the laminated film according to the first embodiment of the present invention.

[0025] The laminate film 50 of this embodiment shown in FIG. 1 includes a base film 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). It is sufficient that the light-transmitting portion is provided in at least a portion of the laminate film 50. In the example shown in FIG. 1, the light-transmitting portion is the entire laminate film 50. The light-transmitting portion of the laminate film 50 has a haze of 30% or less, more preferably 25% or less, 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."

[0026] The substrate film 10 includes a resin layer 12 and a barrier layer 14 .

[0027] 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.

[0028] 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 has one or both of a polypropylene film and a polyethylene terephthalate film. It is more preferable that the resin layer 12 has 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.

[0029] 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. If the haze of the light-transmitting portion of the laminate film 50 can be set to 30% or less, more preferably 25% or less, the resin layer 12 may contain an appropriate additive. The additive may be at least one selected from the group consisting of fillers, antistatic agents, plasticizers, lubricants, and antioxidants.

[0030] 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. As long as the haze of the light-transmitting portion of the laminate film 50 can be reduced to 30% or less, the laminate film 50 may be subjected to an appropriate surface treatment. For example, the surface 12b may be subjected to an appropriate surface treatment that improves 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.

[0031] 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 materials 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 materials 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 made of one of the above-exemplified materials alone or in combination of two or more of them.

[0032] 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 vapor deposition (CVD), dry lamination, extrusion lamination, or the like.

[0033] The adhesive layer 20 is a layer that bonds the barrier layer 14 to the 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.

[0034] 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 more 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.

[0035] 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 odor-causing sulfur compounds 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.

[0036] 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 on the surface so that they can be more stably present inside the adhesive layer 20.

[0037] 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 exist 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.

[0038] 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 used to be mixed into the adhesive component.

[0039] The content of additive particles in the adhesive layer 20 is not particularly limited as long as the haze of the light-transmitting portion of the laminated film 50 is 30% or less, more preferably 25% or less. 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 terms of the transparency of the laminated film, the content of additive particles in the adhesive layer 20 is preferably 0.5% by mass or more and 10% by mass or less. Furthermore, in order to easily achieve both the laminate strength of the adhesive layer 20, the transparency of the laminated film, and the effect of reducing retort odor, the content of additive particles in the adhesive layer 20 is more preferably 1% 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 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.

[0040] 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 an increase 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 for 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.

[0041] For example, from the viewpoint of improving the transparency of the light-transmitting portion of the laminated film 50 and the lamination strength of the adhesive layer 20, it is more preferable that the maximum diameter of the aggregates formed by the additive particles when viewed from a direction perpendicular to the thickness direction of the adhesive layer 20 is 1.0 μm or less, and even more preferable that it is 500 nm or less. Here, the term "aggregate" is used in a broad sense and refers to an apparent mass when observed with a microscope or the like in a direction perpendicular to the thickness direction. There is no particular distinction between whether the apparent mass is formed by an 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 a direction perpendicular to the thickness direction. For example, the maximum diameter of the aggregates can be measured using a scanning electron microscope (cross-sectional SEM). Specifically, the magnification of the cross-sectional SEM is set to 10,000 times, and a rectangular area of ​​50 μm in the width direction is photographed, and the maximum diameter of the aggregates observed is used to determine the size. The measurement points for the size of the aggregates may be at 500 m intervals in the roll direction (length direction) of the laminate film 50 and at 200 mm intervals in the width direction. For example, for a laminate film that is 3000 m long and 600 mm wide, measurements may be taken at six locations every 500 m in the length direction and three locations in the center and 200 mm from the center in the width direction, for a total of 21 locations. However, when measuring the maximum diameter of the aggregates in a packaging bag using the laminate film 50, measurements may be taken at appropriate positions within the light-transmitting portion of the packaging bag.

[0042] The distribution of additive particle aggregates is preferably such that the number of aggregates that are 10% or more and 200% or less of the average particle diameter present in a rectangular region of 50 μm in the width direction is 50 or more. In this case, streaks become invisible, and the visibility of the packaged item can be improved when the laminated film 50 is used as a packaging bag.

[0043] For example, the additive particles are believed to trap odor-causing substances that permeate the adhesive layer 20 by adsorbing them. In order for additive particles to efficiently capture odor-causing substances, it is preferable that the specific surface area of ​​the additive particles is large. Here, the specific surface area represents the surface area per unit mass of the additive particles. For example, the specific surface area of ​​an additive particle is 1 m 2 / g or more, and 2 / g or more is more preferable. 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 perspective of making it easier to handle additive particles in the manufacturing process, the specific surface area of ​​the additive particles is set to 100 m 2 / g or less, and 2 / g is more preferred.

[0044] If the average particle size of the additive particles as primary particles is too large, agglomerates exceeding 1.0 μm are likely to form, so a smaller average particle size of the additive particles is preferable. However, if the average particle size of the additive particles is small to a certain extent, the maximum diameter of the agglomerates will vary depending on the mixing method in the manufacturing process, and the correlation between the average particle size and the maximum diameter of the agglomerates 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 defined as the equivalent circle diameter obtained from an image of the powder magnified 50,000 to 200,000 times using a transmission electron microscope (TEM), and calculated using the following general formula: Formula: Average particle size = Sum of the equivalent circle diameters of the measured particles / Number of measured particles (at least 100 or more). The average particle size of the additive particles is not particularly limited as long as the haze is 30% or less, more preferably 25% or less, but is preferably, for example, 10 nm or more and 50 nm or less, and 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 10 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 50 nm, the specific surface area will be small, which may reduce the effectiveness of capturing odor-causing substances.

[0045] 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.

[0046] 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 is preferably, for example, 7N / 15mm width or more after retorting.

[0047] 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.

[0048] 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 a non-oriented polypropylene resin in order to maintain sufficient adhesion.

[0049] The sealant layer 30 may be formed by laminating a resin composition onto the adhesive layer 20 while forming a film by extrusion lamination, 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.

[0050] 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.

[0051] When preparing the coating liquid, it is more preferable to mix additive particles with the adhesive that forms the adhesive component and disperse the additive particles in the coating liquid so that the size of the additive particle aggregates is 1.0 μm or less. 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, but it is more preferable to disperse the additive particles and the dispersant in a solvent to form a particle dispersion with, for example, NV30%, and then mix the particle dispersion with the adhesive to prepare the coating liquid. 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, bead mills, roll mills, cutter mills, planetary mills, jet mills, attritors, grinders, juicer mixers, homomixers, ultrasonic homogenizers, nanogenizers, and underwater head-on collisions. Particularly preferred is a bead mill, which mixes beads with a particle dispersion in which additive particles and a dispersant are dispersed in a solvent, and disperses the additive particles using beads that have the energy of centrifugal force generated by rotating an agitator at high speed.

[0052] By performing a dispersion process to disperse the finely divided additive particles in the coating liquid using one or more of the above-mentioned means (a bead mill in this embodiment), the growth of aggregates in the coating liquid can be suppressed. 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. By efficiently dispersing the additive particles in the coating liquid and suppressing the growth of aggregates in the coating liquid, an increase in haze is suppressed. The ratio of the haze when additive particles are contained to the haze when no additive particles are contained is preferably 1.10 or less, and more preferably 1.00 or less. By making the ratio of the haze when additive particles are contained to the haze when no additive particles are contained 1.10 or less, a decrease in the transparency of the laminated film 50 can be suppressed. Furthermore, by dispersing the additive particles and suppressing the growth of aggregates, streaks can be suppressed.

[0053] Once the coating solution is prepared, it is more preferable to filter it before coating. For example, by using a filter with a pore size of 1.0 μm or less, it is possible to reduce the size of aggregates after filtration to 1.0 μm or less.

[0054] Because the laminated film 50 includes a barrier layer 14 that has barrier properties against oxygen and water vapor, oxygen and water vapor that have permeated the resin layer 12 are prevented from permeating the adhesive layer 20 and the 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 an 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 suppressed. 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 suppressed.

[0055] The laminated 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 laminated 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 polyvalent metal particles or polyvalent metal compound particles are contained in the light-transmitting portion of the laminated film 50 so that the haze is 30% or less, resulting in high transparency, improving the visibility of the packaged items through the laminated film 50, and suppressing streaks. By incorporating polyvalent metal particles or polyvalent metal compound particles to an extent that the haze is 30% or less, more preferably 25% or less, a decrease in the laminate strength of the adhesive layer 20 is suppressed. Because the polyvalent metal particles or polyvalent metal compound particles are mixed into the adhesive component of the adhesive layer 20, it is also possible to suppress 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. As a result, the effect of reducing odor-causing substances and the laminate strength are less likely to decrease over time.

[0056] As described above, the laminate film 50 of this embodiment can provide a laminate film that allows packaged items to be easily viewed. Furthermore, the laminate film 50 of this embodiment can reduce retort odor and provide a laminate film with good laminate strength. Furthermore, the laminate film 50 of this embodiment can be subjected to a physical defibration treatment using a bead mill, which efficiently disperses additive particles in the coating liquid and suppresses the growth of aggregates in the coating liquid, thereby suppressing an increase in haze and reducing a decrease in transparency and streaks in the laminate film 50.

[0057] [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.

[0058] The laminate film 60 of this embodiment shown in Fig. 2 includes a base film 10A instead of the base film 10 in the laminate film 50 of the first embodiment. The laminate film 60 may be provided with a light-transmitting portion at least in a portion thereof, but in the example shown in Fig. 2, the entire laminate film 60 is a light-transmitting portion. 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.

[0059] The adhesive layer 16 is a layer that bonds the barrier layer 14 and the intermediate layer 18 together. The adhesive layer 16 uses one or more materials selected from the materials exemplified as the adhesive component in the adhesive layer 20. The adhesive layer 16 may be formed of the same material as the adhesive layer 20 in the laminated film 60, or may be formed 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.

[0060] When the adhesive layer 16 contains additive particles, the type, content, specific surface area, layer thickness, and average particle diameter of the additive particles in the adhesive layer 16 are not particularly limited, as long as the haze in the light-transmitting portion of the laminated film 60 is 30% or less, more preferably 25% or less. 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 layer 16 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 size of the adhesive layer 20 in the laminated film 60.

[0061] 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, as long as the haze in the light-transmitting portion of the laminated film 60 is 30% or less, more preferably 25% or less. 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 in the preferred range 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 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 .

[0062] 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 as long as it is a light-transmitting resin layer that can reduce the haze of the laminated film 60 to 30% or less, and more preferably to 25% or less. 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. 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 50, it is possible to suppress the occurrence of pinholes in the laminated film 60, which would cause deterioration of the packaged item. This effect is particularly useful when the packaged item is food.

[0063] The laminated film 60 of this embodiment can be produced 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.

[0064] 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. Therefore, it is possible to provide a laminated film that can reduce retort odor and has good laminate strength, and further, by suppressing an increase in haze, it is possible to suppress a decrease in transparency and make it easy to see the packaged contents. In particular, since the laminated film 60 includes the intermediate layer 18, the properties of the laminated film 60 can be improved according to the properties of the intermediate layer 18. Furthermore, when 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.

[0065] [Third embodiment] A packaging bag and a packaging body according to a third embodiment of the present invention will now be described. FIG. 3 is a schematic front view showing an example of a packaging bag and a package according to a third embodiment of the present invention.

[0066] As shown in FIG. 3, the packaging body 200 of this embodiment includes the packaging bag 100 of this embodiment and an article 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 that is sandwiched between a pair of laminated films 50 and surrounded by the seal section 101, and stores an item 110 to be packaged, such as foodstuffs. 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.

[0067] 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.

[0068] 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 sealed portion 101 at the side end, 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.

[0069] A method for manufacturing the packaging bag 100 and the packaging body 200 will be described. FIG. 4 is a schematic perspective view showing a method for manufacturing a packaging bag according to a third embodiment of the present invention.

[0070] A pair of laminated films 50 cut to fit the outer shape of the packaging bag 100 are prepared. Thereafter, as shown in FIG. 4, 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. This forms a seal 101 at the bottom end and side end. Inside each laminate film 50 surrounded by the seal 101 in a U-shape, a storage section 102 is formed. 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 portion thereof. Thereafter, the sealant layers 30 of the laminated film 50 that face each other at the upper end portion are heat-sealed to form a sealed portion 101 at the upper end portion as well. In this manner, a package 200 as shown in FIG. 3 can be manufactured.

[0071] 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 adsorption of substances that cause retort odor, such as sulfur compounds, generated from the packaged item 110 for a long period of time. Therefore, the packaging bag 100 can 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.

[0072] As described above, the packaging bag 100 and packaging body 200 of this embodiment are provided with the laminated film 50 of the first embodiment, and therefore, like the first embodiment, a packaging bag and packaging body can be provided that can reduce retort odor, have good laminate strength, and make it easy to see the packaged contents.

[0073] [Fourth embodiment] A packaging bag and a packaging body according to a fourth embodiment of the present invention will now be described. FIG. 5 is a schematic perspective view showing an example of a packaging bag and a package according to a fourth embodiment of the present invention.

[0074] As shown in FIG. 5, a packaging body 210 of this embodiment includes a packaging bag 150 and an article 110 to be packaged similar to that of the third embodiment. The packaging bag 150 is a standing pouch comprising 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.

[0075] 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 third embodiment, except that they include a bottom tape 152 and are formed into the shape of a stand-up pouch. 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.

[0076] The packaging bag 150 and the packaging body 210 of this embodiment include the laminated film 50, as in the third embodiment, and therefore have the same functions as in the third embodiment.

[0077] In the above 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 third embodiment, one or both of the pair of laminated films 50 may have a light-shielding portion formed by a printed layer. For example, in the laminated films 50 and 60, the print layer may be provided between the resin layer 12 and the barrier layer . The printing layer is a layer composed of ink made by adding various pigments, plasticizers, desiccants, stabilizers, etc. to a binder resin such as urethane, acrylic, nitrocellulose, or rubber. This printing layer can display characters, pictures, etc. Known printing methods can be used, such as offset printing, gravure printing, flexographic printing, silk screen printing, and inkjet printing. The surface 12b of the resin layer 12 on which the printing layer is formed may be subjected to corona treatment or ozone treatment as a pretreatment. This can improve adhesion between the printing layer and the resin layer 12.

[0078] The layer configurations of the laminate film in the first and second embodiments are merely examples. 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 function of the laminate film is not significantly impaired.

[0079] In the above description of the second embodiment, an example was described in which the 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 the 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 be contained only in the adhesive layer 16.

[0080] In the above description of the second embodiment, an example in which there is one intermediate layer has been described, but the laminated film may include two or more intermediate layers.

[0081] In the above third 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. 3 and 4, instead of the pair of laminated films 50, a pair of laminated films 60 may be used to form the packaging bag 100A and the packaging body 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 packaging body 200A have the same function as the laminated film 60 because they include a pair of laminated films 60.

[0082] In the fourth embodiment, an example in which the packaging bag 150 and the packaging body 210 are formed using a pair of laminated films 50 has been described. However, as shown in FIG. 5, instead of the pair of laminated films 50, a pair of laminated films 60 may be used to form the packaging bag 150A and the 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 are provided with a pair of laminated films 60, and therefore have the same function as the laminated film 60.

[0083] In the above third and fourth 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 on a part of the outer periphery of the packaging bag and the packaging body, the laminate film on 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. For example, if a light-transmitting portion is formed in one laminate film 50 so that the contents of the packaged item can be visually confirmed, the other laminate films 50 do not need to have a light-transmitting portion formed therein.

[0084] In the above third and fourth embodiments, 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.

[0085] In the above third and fourth embodiments, the packaged item 110 is explained as a food product, but the packaged item 110 is not limited to a food product. [Example]

[0086] Next, Examples 1 to 19 of the second embodiment of the present invention will be described together with Comparative Examples 1 to 17. First, a description will be given of the particle dispersions used in the production of the laminate films of Examples 1 to 19 and Comparative Examples 2 to 17. 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 19 and Comparative Examples 2 to 17 are shown in Table 1 below.

[0087] [Table 1]

[0088] [Particle dispersion 11Aa] As shown in Table 1, particle dispersion 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 the solvent, ethyl acetate, to form a mixture. The zinc oxide particles had an average particle diameter of 35 nm and a specific surface area of ​​30 m 2 / g of FINEX-30 (trade name; manufactured by Sakai Chemical Industry Co., Ltd.) was used. The amount of FINEX (registered trademark)-30 added was set so that the solid content concentration of the mixed liquid became 30 mass %. Thereafter, dispersant A containing polyester acid amidoamine salt, alkylcyclohexane, and propylene glycol monomethyl ether acetate was added to the mixture. Dispersant A is a dispersant whose main component is amidoamine acid, 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 bead mill (listed as "bead mill" in [Table 1]). In this way, a particle dispersion liquid 11Aa in which zinc oxide particles were dispersed in a solvent was prepared.

[0089] [Particle dispersion 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.

[0090] [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.

[0091] [Particle dispersion 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 12Ba was prepared in the same manner as particle dispersion 12Aa, except that the amount of dispersant added was 40 parts by mass.

[0092] [Particle dispersion 13Aa, 13Ba] Particle Dispersion 13Aa was prepared in the same manner as Particle Dispersion 11Aa, except that Dispersant C, which contains 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 13Ba was prepared in the same manner as particle dispersion 13Aa, except that the amount of dispersant added was 40 parts by mass.

[0093] [Particle dispersion 14Aa, 14Ba, 14Ca] The particle dispersion 14Aa contains zinc oxide particles having an average particle diameter of 20 nm and a specific surface area of ​​50 m 2 / g, prepared in the same manner as particle dispersion 11Aa. Particle dispersion 14Ba was prepared in the same manner as particle dispersion 14Aa, except that the amount of dispersant added was 40 parts by mass. Particle dispersion 14Ca was prepared in the same manner as particle dispersion 14Aa, except that the amount of dispersant added was 20 parts by mass.

[0094] [Particle dispersion 15Aa, 15Ba] Particle dispersion 15Aa has zinc oxide particles with an average particle diameter of 60 nm and a specific surface area of ​​25 m 2 / g, prepared in the same manner as particle dispersion 11Aa. Particle dispersion 15Ba was prepared in the same manner as particle dispersion 15Aa, except that the amount of dispersant added was 40 parts by mass.

[0095] [Particle dispersion 100a, 200a, 300a, 400a] Particle dispersion 100a was prepared in the same manner as particle dispersion 11Aa, except that no dispersant was added. The particle dispersion 400a contains zinc oxide particles having an average particle diameter of 20 nm and a specific surface area of ​​50 m 2 / g, prepared in the same manner as particle dispersion 100a. Particle dispersion 200a was prepared in the same manner as particle dispersion 100a, except that aluminum oxide (Al2O3) 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, and the specific surface area was 27 m 2 / g. 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 diameter of 20 nm and a specific surface area of ​​50 m 2 / g.

[0096] [Particle dispersion 11Ab, 11Bb, 11Cb] Particle dispersion 11Ab was prepared in the same manner as particle dispersion 11Aa, except that the mixture was stirred for 10 minutes using a stirring blade (described as "stirring only" in Table 1) without performing dispersion treatment using a bead mill. 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.

[0097] [Particle dispersion 14Ab, 14Bb] Particle dispersion 14Ab was prepared in the same manner as particle dispersion 14Aa, except that the dispersion treatment using a bead mill was not carried out and the mixture was stirred for 10 minutes using a stirring blade. Particle dispersion 14Bb was prepared in the same manner as particle dispersion 14Ab, except that the amount of dispersant added was 40 parts by mass.

[0098] [Particle dispersion 100b, 200b, 300b, 400b] Particle dispersion 100b was prepared in the same manner as particle dispersion 100a, except that the dispersion treatment using a bead mill was not carried out and the mixture was stirred for 10 minutes using a stirring blade. Particle dispersion 200b was prepared in the same manner as particle dispersion 200a, except that the dispersion treatment using a planetary bead mill was not carried out 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 bead mill was not carried out 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 bead mill was not carried out and the mixture was stirred for 10 minutes using a stirring blade.

[0099] The manufacturing conditions and evaluation results for Examples 1 to 19 and Comparative Examples 1 to 17 are shown in Tables 2 and 3 below.

[0100] [Table 2]

[0101] [Table 3]

[0102] [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. E5100 had a thickness of 12 μm, a length of 500 mm, and a width of 600 mm. One surface 12b of the resin layer 12 was subjected to a corona treatment, and SiO 2 was deposited on the corona-treated surface 12b using a vacuum deposition machine. x A barrier layer 14 made of the following was formed. Specifically, a deposition material consisting of a mixture of silicon metal powder and silicon dioxide powder was prepared, and the mixture was deposited on the surface 12b using a vacuum deposition machine to form a deposition layer 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.

[0103] Using the particle dispersion 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 particle dispersion 11Aa was stirred for 30 minutes using a stirring blade. The mixture was then filtered through a membrane filter with a pore size of 1 μm to obtain Coating Solution 11Aa used in Example 1. 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.

[0104] Thereafter, the coating liquid 11Aa was applied onto the intermediate layer 18 using a dry lamination machine, and a sealant layer 30 was formed by laminating an 80 μm thick polyolefin-based unstretched co-extruded film. 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 mass %, the same as the amount of particles in the coating liquid.

[0105] Thereafter, the laminated film 60 of Example 1 was attached so that the sealant layers 30 faced each other, to produce a 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.

[0106] [Examples 2 to 19] As shown in Table 2, in Example 2, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 1, except that coating liquid 11Aa used a particle dispersion in which the particle amount of zinc oxide particles was 3.0 mass % and the amount of dispersant added was 20 mass parts. In Example 3, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 2, except that coating liquid 11Ca+ was used, which used a particle dispersion liquid in which the particle amount of zinc oxide particles was 5.0 mass%. In Example 4, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 1, except that coating liquid 11Ba was used, which used a particle dispersion liquid with an added amount of dispersant of 40 parts by mass. In Example 5, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 1, except that a coating liquid 12Aa was used, which used a particle dispersion liquid to which dispersant B was added in an amount of 5 parts by mass as a dispersant. In Example 6, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 5, except that coating liquid 12Ba was used, which used a particle dispersion liquid with an added amount of dispersant of 40 parts by mass. In Example 7, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 1, except that a coating liquid 13Aa was used, which used a particle dispersion liquid to which 5 parts by mass of dispersant C was added as a dispersant. In Example 8, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 7, except that coating liquid 13Ba was used, which used a particle dispersion liquid with an added amount of dispersant of 40 parts by mass. In Example 9, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 1, except that a coating liquid 100a using a particle dispersion liquid to which no dispersant was added was used. In Example 10, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 1, except that coating liquid 11Aa+ was used, which used a particle dispersion liquid in which the particle amount of zinc oxide particles was 9.5 mass%. In Example 11, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 9, except that a coating liquid 100a+ using a particle dispersion liquid in which the particle amount of zinc oxide particles was 9.5 mass% was used. In Example 12, the average particle size was 20 nm and the specific surface area was 50 m 2 A laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 1, except that a coating liquid 14Aa using a particle dispersion liquid in which zinc oxide particles of 1 / g were dispersed was used. In Example 13, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 12, except that coating liquid 14Ca was used, which was a particle dispersion liquid in which the particle amount of zinc oxide particles was 3.0 mass % and the amount of dispersant added was 20 mass parts. In Example 14, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 13, except that coating liquid 14Ca+ was used, which used a particle dispersion liquid in which the particle amount of zinc oxide particles was 5.0 mass%. In Example 15, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 12, except that coating liquid 14Ba was used, which used a particle dispersion liquid with an added amount of dispersant of 40 parts by mass. In Example 16, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 12, except that a coating liquid 400a using a particle dispersion liquid to which no dispersant was added was used. In Example 17, the average particle size was 45 nm and the specific surface area was 27 m 2 A laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 9, except that a coating liquid 200a using a particle dispersion liquid in which aluminum oxide particles of 1 / g were dispersed was used. In Example 18, the average particle size was 20 nm and the specific surface area was 50 m 2 A laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 9, except that a coating liquid 300a using a particle dispersion liquid in which magnesium oxide particles of 1 / g were dispersed was used. In Example 19, a laminated film 60, a packaging bag 100A, and a packaging body 200A were produced in the same manner as in Example 1, except that coating liquid 11Aa- was used, which used a particle dispersion liquid in which the particle amount of zinc oxide particles was 0.8 mass%.

[0107] In each particle dispersion liquid used in Examples 2 to 19, the polyvalent metal compound particles were less likely to aggregate due to the dispersion treatment. Therefore, most of the polyvalent metal compound particles passed through the membrane filter during the filtration process when preparing each coating liquid. Therefore, the content of polyvalent metal compound particles in the adhesive layer 20 of the laminated film 60 was the same as the amount of particles in the coating liquid.

[0108] [Comparative Examples 1 to 17] In Comparative Example 1, no polyvalent metal particles or polyvalent metal compound particles were used, and therefore, no dispersion treatment using a bead mill was performed, and an adhesive layer was formed using only a polyurethane-based adhesive. The laminated film, packaging bag, and packaging body 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. In Comparative Example 2, a laminated film, a packaging bag, and a package of Comparative Example 2 were produced in the same manner as in Example 9, except that the coating liquid 100b was used instead of the coating liquid 100a. In Comparative Example 3, a laminated film, a packaging bag, and a packaging body of Comparative Example 3 were produced in the same manner as in Comparative Example 2, except that Coating Liquid 100b+, which uses a particle dispersion liquid in which the particle amount of zinc oxide particles is 3.0 mass %, was used. In Comparative Example 4, a laminated film, a packaging bag, and a package of Comparative Example 4 were produced in the same manner as in Example 1, except that Coating Liquid 11Ab was used instead of Coating Liquid 11Aa. In Comparative Example 5, a laminated film, a packaging bag, and a packaging body were produced in the same manner as in Comparative Example 4, except that Coating Liquid 11Cb was used, which used a particle dispersion liquid in which the particle amount of zinc oxide particles was 3.0 mass % and the amount of dispersant added was 20 mass parts. In Comparative Example 6, the laminated film, packaging bag, and packaging body of Comparative Example 6 were prepared in the same manner as in Comparative Example 4, except that coating liquid 11Bb was used, which used a particle dispersion liquid with an added amount of dispersant of 40 parts by mass. In Comparative Example 7, a laminated film, a packaging bag, and a package of Comparative Example 7 were produced in the same manner as in Example 17, except that the coating liquid 200b was used instead of the coating liquid 200a. In Comparative Example 8, a laminated film, a packaging bag, and a package of Comparative Example 8 were produced in the same manner as in Example 18, except that the coating liquid 300b was used instead of the coating liquid 300a. In Comparative Example 9, a laminated film, a packaging bag, and a packaging body were produced in the same manner as in Comparative Example 2, except that Coating Liquid 100b++, which uses a particle dispersion liquid in which the particle amount of zinc oxide particles is 9.5 mass %, was used. In Comparative Example 10, the laminated film, packaging bag, and packaging body of Comparative Example 10 were produced in the same manner as in Comparative Example 7, except that coating liquid 200b+, which uses a particle dispersion liquid in which the particle amount of aluminum oxide particles is 9.5 mass %, was used. In Comparative Example 11, the laminated film, packaging bag, and packaging body of Comparative Example 11 were produced in the same manner as in Comparative Example 8, except that coating liquid 300b+, which uses a particle dispersion liquid in which the particle amount of magnesium oxide particles is 9.5 mass %, was used. In Comparative Example 12, a laminated film, a packaging bag, and a package of Comparative Example 12 were produced in the same manner as in Example 12, except that Coating Liquid 14Ab was used instead of Coating Liquid 14Aa. In Comparative Example 13, the laminated film, packaging bag, and packaging body of Comparative Example 13 were prepared in the same manner as in Comparative Example 12, except that coating liquid 14Bb, which uses a particle dispersion liquid with an added amount of dispersant of 40 parts by mass, was used. In Comparative Example 14, a laminated film, a packaging bag, and a packaged body were produced in the same manner as in Example 16, except that the coating liquid 400b was used instead of the coating liquid 400a. In Comparative Example 15, a laminated film, a packaging bag, and a packaging body were produced in the same manner as in Example 1, except that coating liquid 11Aa++, which uses a particle dispersion liquid in which the particle amount of zinc oxide particles is 11% by mass, was used. In Comparative Example 16, the zinc oxide particles had an average particle size of 60 nm and a specific surface area of ​​25 m 2 A laminated film, a packaging bag, and a package of Comparative Example 16 were produced in the same manner as in Example 1, except that Coating Solution 15Aa using a particle dispersion liquid with a particle concentration of 15Ag / g was used. In Comparative Example 17, the laminated film, packaging bag, and packaging body of Comparative Example 17 were prepared in the same manner as in Comparative Example 16, except that coating liquid 15Ba, which uses a particle dispersion liquid with an added amount of dispersant of 40 parts by mass, was used.

[0109] [Measurement items] To evaluate each Example and Comparative Example, the haze, the ratio of the haze to the haze of Comparative Example 1 (haze ratio), the maximum diameter, minimum diameter, and average diameter of the aggregates, the hydrogen sulfide (HS) concentration, and the laminate strength were measured.

[0110] Haze was measured in accordance with JIS-K-7136 using the laminated films of each Example and Comparative Example as test samples. A haze meter NDH 2000 (trade name, manufactured by Nippon Denshoku Industries Co., Ltd.) was used to measure haze. A 5V 9W halogen lamp was used as the light source, and a silicon photocell was used as the light-receiving element. The measurement area was a rectangular area of ​​4 cm x 4 cm. Measurement locations in the roll direction (length direction) of the laminated film were two locations: near the coating start position of the coating liquid and near the coating end position. The distance between the coating start position and the coating end position was 500 m. Measurement locations in the width direction of each measurement location in the roll direction were three locations: the center and two locations 200 mm away from the center on both sides. The average value of the measurements at six measurement locations is listed in the "Haze" column of Table 3.

[0111] The size of the aggregates was measured by taking cross-sectional images of the laminated films of each Example and Comparative Example as test samples at a magnification of 10,000 times using a scanning electron microscope, continuously photographing 50 μm along the adhesive layer.

[0112] 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 retorted by heating at 120°C for 60 minutes. After retorting, the packages were stored in a refrigerator for one week. After this, the aqueous solution inside each package was sampled, and the hydrogen sulfide concentration was determined using 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 3.

[0113] 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. Before retort treatment, the corresponding packaging bags 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.) using the T-peel method (crosshead speed: 300 mm / min). The measurement results are shown in the "Laminate Strength Retort" column in Table 3. 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 Retort" column in Table 3. However, in Table 3, (N / 15 mm width) is simply expressed as (N).

[0114] [Measurement results] As shown in Tables 2 and 3, the laminate films 60 of Examples 1 to 19, in which the average particle size of the additive particles was 10 nm or more and 50 nm or less and the particle amount was 0.5 mass % or more and 10 mass % or less, had a haze ratio of 1.10 or less, more specifically, a haze ratio of 1.00. Generally, the haze increases as the particle amount increases, but the haze ratios of the laminate films 60 of Examples 1 to 19 were equivalent to that of the laminate film of Comparative Example 1, which did not contain additive particles.

[0115] The average diameter of the aggregates observed in the laminate films 60 of Examples 1 to 19 was 20 nm or more and 120 nm or less, and the maximum diameter (long diameter) was 250 nm or less. The "average diameter of the aggregates" is the value obtained by summing all the diameters (long diameters) of the aggregates and dividing this by the number of aggregates. Taking the average particle diameter of the additive particles into consideration, it was confirmed that the number of aggregates observed in the laminate films 60 of Examples 1 to 19 was 50 or more, each of which had an average particle diameter of 10% or more and 200% or less of the average particle diameter present in a rectangular region of 50 μm in the width direction. In other words, it was confirmed that many fine aggregates with small maximum diameters were dispersed.

[0116] On the other hand, among Comparative Examples 2 to 17, the laminate films 60 of Comparative Examples 2 to 14, in which the dispersion treatment was only stirring, had haze ratios of 1.12 to 1.32, which were not as good as the laminate films 60 of Examples 1 to 19.

[0117] The average diameter of the aggregates observed in the laminate films 60 of Comparative Examples 2 to 14 was 2.0 μm or more, and the maximum diameter (long diameter) was 3.0 μm or more. Taking into account the average particle diameter of the additive particles, it was confirmed that the aggregates observed in the laminate films 60 of Comparative Examples 2 to 15 were composed of aggregates of approximately 100 to several hundred additive particles.

[0118] 6 is an example of a photographic image of the laminated film of Example 2. FIG. 7 is an example of a photographic image of the laminated film of Comparative Example 5. As shown in Figure 6, no aggregates larger than 1 µm were observed in the laminate film of Example 2. As shown in Figure 7, the size of the aggregates observed in the laminate film of Comparative Example 5 exceeded 3.0 µm.

[0119] The adhesive layers in Examples 1 to 19 were produced by dispersing additive particles, dispersant, and solvent in a mixed state in the coating liquid preparation step using a bead mill, and therefore, it is believed that the amount of aggregation that adversely affects haze was smaller than in Comparative Examples 2 to 14, in which dispersion was performed by stirring alone. Therefore, in laminated film 60 having an adhesive layer produced by dispersion using a bead mill and its production method, it is possible to add various particles that can exhibit high functionality without adversely affecting haze.

[0120] Furthermore, the laminated films of Examples 1 to 18 not only had a haze ratio of 1.10 or less, but also received good ratings for visibility, odor, and strength. Example 19, which was subjected to dispersion treatment using a bead mill and had a haze ratio of 1.10 or less but contained 0.8% by mass of particles, did not receive good ratings for odor or strength. This is thought to be because the small particle amount resulted in insufficient odor reduction and strength.

[0121] On the other hand, in Comparative Example 15, where a dispersion treatment using a bead mill was performed after mixing additive particles, dispersant, and solvent in the coating liquid preparation step, but the particle amount exceeded 10 mass%, good visibility was not obtained. Also, in Comparative Examples 16 and 17, where a dispersion treatment using a bead mill was performed after mixing additive particles, dispersant, and solvent in the coating liquid preparation step, but the average particle size of the additive particles exceeded 50 nm, good visibility was not obtained compared to Examples 1 to 19, and the haze ratio did not satisfy the requirement of 1.10 or less.

[0122] The lamination strength of the packaging bags of each Example and Comparative Example before retort treatment was approximately equal, ranging from 11 N / 15 mm width to 12 N / 15 mm width. In contrast, the laminate strength after retort treatment was reduced in all cases. Specifically, Examples 1 to 18 had a reduction of 8 N / 15 mm width and 3 N / 15 mm width. In addition, Example 19 showed a decrease of 5 N / 15 mm width. Comparative Example 1, which did not contain additive particles, showed only a decrease of 2N / 15mm width, but Comparative Examples 2 to 17 showed decreases of 3N / 15mm width to 8N / 15mm width. This shows that the laminate strength tends to decrease as the amount of particles in the adhesive layer increases.

[0123] [Evaluation method and criteria] The evaluation was carried out on visibility, retort odor, laminate strength (before retort), laminate strength (after retort), and laminate strength (overall). Regarding visibility, a haze ratio of 25% or less was rated as "A," a haze ratio of more than 25% but less than 28% was rated as "B," and a haze ratio of more than 28% was rated as "C." Regarding retort odor (listed as "odor" in [Table 3]), hydrogen sulfide concentrations of 0.04 mg / L or less were rated as "A," those between 0.04 mg / L and 0.25 mg / L were rated as "B," and those above 0.25 mg / L were rated as "C." Regarding laminate strength, laminate strength of 7N / 15mm width or more after retort processing was rated as "A", and laminate strength of less than 7N / 15mm width was rated as "B".

[0124] [comprehensive evaluation] The overall evaluation was "A" if visibility, retort odor, and laminate strength (overall) were all rated "A," "B" if there were two "A" ratings and one "B" rating, and "C" if there were two or more "B" ratings or a "C" rating.

[0125] As shown in Table 3, the overall evaluation of Examples 1 to 18 was all rated "A," and the overall evaluation of Example 19 was rated "B." All of Examples 1 to 19 had a haze ratio of 1.10 or less, and good results were obtained in terms of visibility. In Examples 1 to 19, the retort odor was all improved compared to Comparative Example 1, and favorable results were obtained. In Examples 1 to 19, the laminate strength was all rated as "B" or higher, and good results were obtained.

[0126] That is, Examples 1 to 19 showed good results in terms of visibility, retort odor, and laminate strength, and it was confirmed that the present invention exhibits the effect of solving the problems.

[0127] 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.

[0128] The present invention also discloses the following. [1] A laminated film having a light-transmitting portion through which visible light transmits in a thickness direction, a substrate film having a barrier 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 haze of the light-transmitting portion measured in accordance with the haze measurement method specified in JIS-K-7136 is 25% or less. Laminated film. [2] The laminated film according to the above [1], wherein the ratio of the solid content of the polyvalent metal particles or the polyvalent metal compound particles to the total mass of the solid content of the polyvalent metal particles or the polyvalent metal compound particles in the adhesive layer is 0.5 mass% or more and 10 mass% or less. [3] The laminated film according to the above [1] or [2], wherein the average particle size of the polyvalent metal particles or the polyvalent metal compound particles is 10 nm or more and 50 nm or less. [4] The laminated film according to any one of [1] to [3] above, wherein the distribution of aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles in the adhesive layer is such that the number of aggregates present in a rectangular region of 50 μm in the width direction is 50 or more and is 10% or more and 200% or less of the average particle diameter. [5] In the adhesive layer, the average diameter of the aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles as viewed in a direction perpendicular to the thickness direction is 20 nm or more and 120 nm or less. The laminated film according to any one of the above [1] to [4]. [6] The polyvalent metal particles or the polyvalent metal compound particles have a specific surface area of ​​1 m 2 The laminated film according to any one of the above [1] to [5], wherein the viscosity is 1 / g or more. [7] 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 the above [1] to [6]. [8] The adhesive component is a cured product of a two-component curing adhesive. The laminated film according to any one of the above [1] to [7]. [9] In the adhesive layer, the maximum diameter of the aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles as viewed in a direction perpendicular to the thickness direction is 1.0 μm or less. The laminated film according to any one of the above [1] to [8].

[10] The base film has a nylon layer. The laminated film according to any one of the above [1] to [9].

[11] A packaging bag made by bonding films together, A packaging bag comprising the laminated film according to any one of the above [1] to

[10] .

[12] The packaging bag according to claim 11; An item to be packaged to be contained in the packaging bag; A packaging bag comprising the laminated film according to any one of the above items [1] to

[11] .

[13] The packaged item contains a sulfur compound. A packaging bag comprising the laminated film according to any one of the above [1] to

[12] . [Explanation of symbols]

[0129] 10, 10A base film 12 Resin layer 14 Barrier Layer 16 Adhesive layer 18 Middle Class 20 Adhesive layer 30 Sealant Layer 50, 60 laminated film 100, 100A, 150, 150A packaging bag 110 Items to be packaged 200, 200A, 210 package

Claims

1. A laminated film having a light-transmitting portion through which visible light transmits in a thickness direction, a substrate film having a barrier 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 haze measured in the light-transmitting portion in accordance with the haze measurement method specified in JIS-K-7136 to the haze measured in the light-transmitting portion when the adhesive layer does not contain the polyvalent metal particles and the polyvalent metal compound particles, measured in accordance with the same measurement method, is 1.10 or less; a ratio of the solid content of the polyvalent metal particles or the polyvalent metal compound particles to the total mass of the solid content of the polyvalent metal particles or the polyvalent metal compound particles and the solid content of the adhesive in the adhesive layer is 1.0 mass% or more and 10 mass% or less; the average particle size of the polyvalent metal particles or the polyvalent metal compound particles is 10 nm or more and 50 nm or less; In the adhesive layer, the distribution of the aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles is such that the number of aggregates present in a rectangular region of 50 μm in the width direction is 50 or more and is 10% or more and 200% or less of the average particle diameter, A laminated film, wherein in the adhesive layer, the aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles have an average diameter of 20 nm or more and 120 nm or less as viewed in a direction perpendicular to the thickness direction.

2. The specific surface area of ​​the polyvalent metal particles or the polyvalent metal compound particles is 1 m ２ The laminated film according to claim 1, wherein the modulus of elasticity is 1 / g or more.

3. 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 claim 1 or 2.

4. The adhesive component is a cured product of a two-component curing adhesive. The laminated film according to any one of claims 1 to 3.

5. In the adhesive layer, the maximum diameter of the aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles as viewed in a direction perpendicular to the thickness direction is 1.0 μm or less. The laminated film according to any one of claims 1 to 4.

6. The base film has a nylon layer. The laminated film according to any one of claims 1 to 5.

7. A packaging bag made by bonding films together, The film comprises the laminated film according to any one of claims 1 to 6. packaging bag.

8. The packaging bag according to claim 7; An item to be packaged to be contained in the packaging bag; A packaging body comprising:

9. The packaged item contains a sulfur compound. The package of claim 8.

10. a substrate film having a barrier 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 stacked in this order, A method for producing a laminated film having a light-transmitting portion that transmits visible light in a thickness direction, comprising: the ratio of the haze measured in the light-transmitting portion in accordance with the haze measurement method specified in JIS-K-7136 to the haze measured in the light-transmitting portion when the adhesive layer does not contain the polyvalent metal particles and the polyvalent metal compound particles, measured in accordance with the same measurement method, is 1.10 or less; In the laminate film, a ratio of the solid content of the polyvalent metal particles or the polyvalent metal compound particles to the total mass of the solid content of the polyvalent metal particles or the polyvalent metal compound particles and the solid content of the adhesive in the adhesive layer is 0.5 mass% or more and 10 mass% or less, the average particle size of the polyvalent metal particles or the polyvalent metal compound particles is 10 nm or more and 50 nm or less; In the adhesive layer, the distribution of the aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles is such that the number of aggregates present in a rectangular region of 50 μm in the width direction is 50 or more and is 10% or more and 200% or less of the average particle diameter, In the adhesive layer, the average diameter of aggregates formed by the polyvalent metal particles or the polyvalent metal compound particles as viewed in a direction perpendicular to the thickness direction is 20 nm or more and 120 nm or less, The step of forming the adhesive layer includes: a coating liquid preparation step of preparing a coating liquid by mixing the polyvalent metal particles or the polyvalent metal compound particles with an adhesive that forms the adhesive component after curing, In the coating liquid preparation step, the polyvalent metal particles or the polyvalent metal compound particles, a dispersant, and a solvent are mixed and then subjected to a dispersion treatment using a bead mill. A method for manufacturing a laminated film.

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