JP7382191B2 - Packaging film and packaging - Google Patents

Description

The present invention relates to a film for packaging and a packaging.

2. Description of the Related Art Hitherto, microwave oven packages have been widely used for heating and cooking housed foods and the like in a microwave oven in a packaged state. For example, Patent Document 1 discloses a package for a microwave oven in which contents are housed and a pressure discharge part is formed to release internal pressure that increases during heating in the microwave oven to the outside.

Japanese Patent Application Publication No. 2010-83507

However, when food containing oil (fried food, etc.) is sealed in a microwave oven package and cooked, the microwave's microwaves concentrate on the oil, causing the food to harden due to overheating, or causing the food to become too hot. Unevenness may occur more easily. Furthermore, when fried foods contain a large amount of salt, only the surface of the food is heated and the surface may be burnt (hereinafter also referred to as "deterioration of food quality").
In addition, if moisture is present inside the microwave package, the moisture released during heating will penetrate deep-fried foods, etc., degrading the original texture of the food.

The present invention has been made in view of the above circumstances, and aims to provide a film for packaging and a packaging body that can suppress deterioration in food quality and maintain the original texture of the food.

As a result of extensive studies, the present inventors have found that a film for packaging bodies having the following configuration can solve the above problems.
That is, the film for packaging of the present invention has the following configuration.
[1] A water vapor barrier material and a sealant material located on one surface of the water vapor barrier material, the sealant material comprising a moisture absorption layer containing zeolite and a sealing layer, and the water vapor barrier material From the side, the moisture absorption layer and the sealing layer are located in this order, the zeolite has a molar ratio expressed by SiO ₂ /Al ₂ O ₃ of 70/30 or less, and the sealant material has a water content of 1. % or more by mass, a film for packaging.
[2] The film for packaging according to [1], wherein the sealant material has a moisture content of 30% by mass or less.
[3] [1] or [2], wherein the sealant material further includes a laminate layer, and the laminate layer, the moisture absorption layer, and the sealing layer are located in this order from the water vapor barrier material side. The packaging film described in .
[4] A package made from the film for packages according to any one of [1] to [3].

According to the packaging film of the present invention, deterioration in food quality can be suppressed and the original texture of the food can be maintained.

FIG. 1 is a sectional view of a film for packaging according to a first embodiment of the present invention. It is a sectional view of the film for packaging bodies concerning a second embodiment of the present invention.

The film for packaging of the present invention includes a water vapor barrier material and a sealant material located on one surface of the water vapor barrier material.
EMBODIMENT OF THE INVENTION Hereinafter, embodiment is mentioned and demonstrated about the film for packaging bodies of this invention.

[First embodiment]
A film for packaging according to a first embodiment of the present invention will be described with reference to the drawings.
The packaging film 1 shown in FIG. 1 has a base material 10, a water vapor barrier material 20, and a sealant material 30 laminated in this order. That is, the packaging film 1 includes a water vapor barrier material 20 and a sealant material 30 located on one surface of the water vapor barrier material 20.
The thickness T ₁ of the packaging film 1 is not particularly limited, but is preferably, for example, 35 to 250 μm, more preferably 40 to 200 μm, and even more preferably 50 to 150 μm. When the thickness T ₁ is equal to or greater than the above lower limit, the strength of the packaging film 1 is likely to be increased. When the thickness T ₁ is less than or equal to the above upper limit, the flexibility of the packaging film 1 is increased and handling becomes easier.

≪Base material≫
Examples of the base material 10 include resin films, paper, and laminates thereof.
Examples of resin films include polyethylene terephthalate (PET) such as biaxially oriented polyethylene terephthalate, polyolefins such as biaxially oriented polypropylene (OPP), unoriented polypropylene (CPP), high density polyethylene (HDPE), and medium density polyethylene (MDPE). , polyamide (PA) such as biaxially oriented nylon (ONY), polyvinyl chloride (PVC), and laminates thereof. Among these, PET, polypropylene (PP), PA, and PVC are preferred, and biaxially oriented PET, OPP, and PVC are more preferred.
Examples of the laminate include a laminate of the resin films mentioned above.
This base material 10 may be printed on its surface or between layers.

The thickness T ₁₀ of the base material 10 is determined in consideration of the material, structure, etc., and is preferably 5 to 100 μm, more preferably 10 to 50 μm, for example. When the thickness T ₁₀ of the base material 10 is equal to or greater than the above lower limit, the strength of the packaging film 1 is likely to be increased. When the thickness T ₁₀ of the base material 10 is less than or equal to the above upper limit value, the flexibility of the packaging film 1 is increased and handling becomes easier.

≪Water vapor barrier material≫
The water vapor barrier material 20 has water vapor barrier properties. The water vapor barrier material 20 includes an inorganic vapor-deposited layer of silica, alumina, etc. deposited on the base material 10, polyvinylidene chloride (PVDC), ethylene-vinyl alcohol polymer (EVOH), polyvinyl alcohol (PVOH), PA, polyacrylonitrile. (PAN), acrylic coated PET in which EVOH, etc. are applied to PET.
As the water vapor barrier material 20, an inorganic vapor deposited layer is preferable, and a silica vapor deposited layer is more preferable.

The water vapor permeability of the water vapor barrier material 20 is, for example, preferably 3 g/(m ² ·day) or less, more preferably 1 g/(m ² ·day) or less. When the water vapor permeability of the water vapor barrier material 20 is less than or equal to the above upper limit value, it is possible to sufficiently suppress moisture from entering the package from outside, and it becomes easier to maintain the original texture of the food.
Note that the water vapor permeability in this specification is a value determined by the humidity sensor method of JIS K7129:2008.
The water vapor permeability of the water vapor barrier material 20 can be adjusted by the materials and thicknesses of the base material 10, the water vapor barrier material 20, and the moisture absorption layer 34 described below, and the combination thereof.

The thickness of the water vapor barrier material 20 is determined by taking into account the material, structure, etc. The thickness T ₂₀ of the water vapor barrier material 20 is, for example, preferably 10 to 30 μm, more preferably 12 to 15 μm. When the thickness T ₂₀ of the water vapor barrier material 20 is equal to or greater than the above lower limit, a decrease in water vapor barrier properties can be suppressed, and the original texture of the food can be easily maintained. When the thickness T ₂₀ of the water vapor barrier material 20 is less than or equal to the above upper limit value, the flexibility of the packaging film 1 is increased and handling becomes easier.

≪Sealant material≫
In this embodiment, the sealant material 30 includes a laminate layer 32, and the laminate layer 32, the moisture absorbing layer 34, and the sealing layer 36 are located in this order from the water vapor barrier material 20 side. That is, the sealant material 30 is a laminate in which a laminate layer 32, a moisture absorbing layer 34, and a sealing layer 36 are arranged in this order from the water vapor barrier material 20 side.

The moisture content of the sealant material 30 is 1% by mass or more based on the total mass of the sealant material 30, preferably 1 to 30% by mass, more preferably 3 to 20% by mass, and even more preferably 5 to 10% by mass. When the moisture content of the sealant material 30 is equal to or higher than the above lower limit value, crystal water possessed by the zeolite contained in the moisture absorbing layer 34 is appropriately released into the package, and the surface of the food contained in the package may be burnt. Easy to suppress. Therefore, deterioration in food quality can be easily suppressed. When the moisture content of the sealant material 30 is below the above upper limit, it is easy to maintain an appropriate amount of moisture inside the package. Therefore, it is easy to maintain the original texture of the food.
The moisture content of the sealant material 30 is determined from the content and composition (amount of crystal water) of zeolite contained in the moisture absorbing layer 34 and a value measured by a Karl Fischer moisture meter.
More specifically, the content of crystal water is calculated from the content (mass) of zeolite contained in the moisture absorption layer 34 and the crystal water ratio of the zeolite composition, and the water content of the sealant material 30 is calculated using a Karl Fischer moisture meter. The moisture content of the sealant material 30 can be determined by measuring the amount of moisture absorbed and calculating the amount of moisture absorbed.

The moisture content of the sealant material 30 can be adjusted by the type and content of zeolite contained in the moisture absorption layer 34, and a combination thereof.

<Laminate layer>
The laminate layer 32 mainly has the role of increasing the adhesiveness between the sealant material 30 and the water vapor barrier material 20.
Examples of the resin constituting the laminate layer 32 include polyolefins such as low density polyethylene (LDPE), linear LDPE (LLDPE), MDPE, HDPE, and PP, EVOH, ethylene-vinyl acetate copolymer (EVA), and ethylene-vinyl acetate copolymer (EVA). Examples include acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate copolymer (EEA), and ionomer. These resins may be used alone or in combination of two or more.

The thickness T ₃₂ of the laminate layer 32 is preferably 5 to 50 μm, more preferably 10 to 20 μm. When the thickness T ₃₂ of the laminate layer 32 is equal to or greater than the above lower limit, the adhesive strength of the sealant material 30 to the water vapor barrier material 20 can be easily maintained. When the thickness T ₃₂ of the laminate layer 32 is less than or equal to the above upper limit value, the film for packaging 1 can be made thinner, the flexibility of the film for packaging 1 is increased, and handling becomes easier.

<Moisture absorption layer>
The moisture absorption layer 34 contains zeolite. As the moisture absorption layer 34, a resin film containing zeolite can be mentioned.
Examples of the resin constituting the moisture absorption layer 34 include those similar to the resin constituting the laminate layer 32. The resin forming the moisture absorption layer 34 may be the same as or different from the resin forming the laminate layer 32.

Zeolite contained in the moisture absorption layer 34 is generally represented by the following formula (1).
(M ^I , M ^II _1/2 ) _m (Al _m Si _n O _{2 (m+n)} ) xH ₂ O... (1)
In formula (1), M ^I is an alkali metal such as lithium, sodium, potassium, etc., M ^II is an alkaline earth metal such as calcium, magnesium, barium, etc., m, n, and x are positive numbers, and n ≧m.
By containing zeolite, the moisture absorbing layer 34 can appropriately release the crystal water of the zeolite itself inside the package, thereby suppressing the surface of the food contained in the package from burning. Therefore, deterioration in food quality can be easily suppressed. In addition, by containing zeolite, the moisture absorbing layer 34 adsorbs excess water present inside the package and easily maintains the original texture of the food.

Zeolite has a molar ratio expressed by SiO ₂ /Al ₂ O ₃ (hereinafter also referred to as SiO ₂ /Al ₂ O ₃ ratio) of 70/30 or less. The SiO ₂ /Al ₂ O ₃ ratio of the zeolite is preferably 50/50 or less, more preferably 30/70 or less. When the SiO ₂ /Al ₂ O ₃ ratio of the zeolite is below the above-mentioned upper limit, the hydrophilicity of the zeolite becomes high and it is easy to adsorb excess water present inside the package.
The lower limit of the SiO ₂ /Al ₂ O ₃ ratio of the zeolite is not particularly limited, and is preferably 2/98 or more, for example.

The amount of crystal water in the zeolite (the amount of crystal water, x in the above formula (1)) is preferably 30 mol or less, more preferably 20 mol or less per 1 mol of zeolite. When the amount of water of crystallization in the zeolite is below the above upper limit, excess water present inside the package is more easily adsorbed. The lower limit of the amount of water of crystallization in the zeolite is not particularly limited, and is preferably 0.1 mole or more per mole of zeolite.
Examples of commercially available zeolites include Hydrophobic Molecular Sieve (trade name, manufactured by Union Showa Corporation), High Silica Zeolite (trade name, manufactured by Tosoh Corporation), and the like.

The average particle diameter of the zeolite is preferably 5 to 24 μm, more preferably 5 to 20 μm, and even more preferably 5 to 15 μm. When the average particle diameter of the zeolite is within the above numerical range, secondary aggregation of the zeolite is easily suppressed, and damage to the moisture absorption layer 34 due to the secondary agglomerated particles is easily suppressed.

The content of zeolite in the moisture absorption layer 34 is preferably 10 to 70% by mass, more preferably 20 to 50% by mass. When the content of zeolite is at least the above lower limit, the water of crystallization contained in the zeolite is appropriately released into the package, making it easy to prevent the surface of the food contained in the package from burning. Therefore, deterioration in food quality can be easily suppressed. In addition, when the content of zeolite is at least the above lower limit, it becomes easier to adsorb excess water present inside the package, making it easier to maintain the original texture of the food. When the content of zeolite is below the above upper limit, it is easy to form the moisture absorbing layer 34 without defects.

The thickness T ₃₄ of the moisture absorption layer 34 is preferably 10 μm or more, more preferably 15 to 100 μm, even more preferably 20 to 80 μm, and particularly preferably 30 to 70 μm. When the thickness T _{34 of the moisture absorbing layer 34} is equal to or greater than the above lower limit, crystal water contained in the zeolite is appropriately released into the package, and it is easy to prevent the surface of the food contained in the package from burning. Therefore, deterioration in food quality can be easily suppressed. In addition, when the thickness T ₃₄ of the moisture absorbing layer 34 is equal to or greater than the above lower limit, it becomes easier to adsorb excess water present inside the package, making it easier to maintain the original texture of the food. When the thickness T 34 of the moisture absorbing layer ₃₄ is less than or equal to the above upper limit, the packaging film 1 can be made thinner, the flexibility of the packaging film 1 is increased, and handling becomes easier.

<Seal layer>
The sealing layer 36 improves the sealing properties of the packaging film 1.
The seal layer 36 may be the same as the laminate layer 32. Among these, LDPE, LLDPE, MDPE, and HDPE are preferred, and LDPE and LLDPE are more preferred.
The seal layer 36 and the laminate layer 32 may be the same or different.
Further, the seal layer 36 may have a single layer structure or a multilayer structure.

The thickness T ₃₆ of the sealing layer 36 is determined in consideration of the material and the like, and is, for example, preferably 5 to 100 μm, more preferably 5 to 90 μm, even more preferably 10 to 80 μm, and particularly preferably 10 to 50 μm. When the thickness T ₃₆ of the sealing layer 36 is greater than or equal to the above lower limit, the sealing performance of the packaging film 1 can be further improved. When the thickness T 36 of the sealing layer ₃₆ is less than or equal to the above upper limit value, the amount of heat when sealing the package film 1 can be suppressed, and the productivity of the package can be increased. In addition, if the thickness T ₃₆ of the sealing layer 36 is less than or equal to the above upper limit, the zeolite in the moisture absorbing layer 34 is likely to be activated when the package is heated and cooked, and the zeolite is not activated. This makes it easier to maintain the same state.

<<Method for manufacturing film for packaging>>
The method for manufacturing the packaging film 1 includes a step of manufacturing a laminated film from the water vapor barrier material and a sealant material (a laminated film manufacturing step), and a step of subjecting the laminated film to a heat treatment (heat treatment step).

<Laminated film manufacturing process>
In the laminated film manufacturing process, a laminated film is manufactured. Examples of the method for manufacturing the laminated film include conventionally known manufacturing methods, such as the following method.
The method for manufacturing a laminated film of the present embodiment includes a process for obtaining a base material 10 (base material production process), a process for obtaining a sealant material 30 (sealant material production process), and a process for obtaining a base material 10, a water vapor barrier material 20, and a sealant material. 30 (lamination process).

The method for obtaining the base material 10 in the base material manufacturing process is selected from conventionally known methods such as an inflation method, a T-die method, and a coextrusion method, depending on the material, structure, etc. of the base material 10.

A method for obtaining the sealant material 30 in the sealant material manufacturing process is selected from conventionally known methods depending on the material, structure, etc. of the sealant material 30.
As a method for obtaining the sealant material 30, for example, the sealant material 30, which is a laminate of a laminate layer 32, a moisture absorbing layer 34, and a sealing layer 36, is produced by a coextrusion method using a T-die coextruder, an inflation coextruder, or the like. There are several ways to obtain this.

The method of laminating the base material 10, the water vapor barrier material 20, and the sealant material 30 in the lamination process is selected from conventionally known methods such as dry lamination, for example.
In the dry lamination method, for example, an adhesive is applied to one material to be laminated, and after drying, this is pressure-bonded to another material to obtain a laminated film. The obtained laminated film is wound up into a roll, for example.

<Heat treatment process>
After producing the laminated film as described above, a heat treatment step is performed in which the laminated film is subjected to heat treatment.
By heating the laminated film, the zeolite in the moisture absorption layer 34 is activated. By activating zeolite, its water adsorption properties are increased. In addition, by activating the zeolite, it becomes easier to release the water of crystallization that the zeolite itself has.

The moisture absorption layer 34 in this embodiment is provided between the laminate layer 32 and the seal layer 36.
That is, the moisture absorbing layer 34 is configured not to directly contact outside air (water vapor). Thereby, the zeolite in the moisture absorption layer 34 is sufficiently activated when the heat treatment is performed. Moreover, the activated state of the zeolite is easily maintained.

The temperature of the heat treatment is preferably 30 to 90°C, more preferably 35 to 50°C.
When the temperature of the heat treatment is equal to or higher than the above lower limit, the zeolite is sufficiently activated and sufficient water adsorption properties are likely to be obtained. Therefore, it is easy to maintain the original texture of the food. When the temperature of the heat treatment is below the above upper limit value, it is easy to suppress damage to the film constituting the laminate due to heat.

The heat treatment time is preferably 5 hours or more, more preferably 5 to 96 hours, and even more preferably 12 to 48 hours. When the heat treatment time is equal to or longer than the above lower limit, the zeolite is sufficiently activated and sufficient water adsorption properties are likely to be obtained. Therefore, it is easy to maintain the original texture of the food. When the heat treatment time is equal to or less than the above upper limit, the productivity of the packaging film 1 is easily improved.
The heat treatment of the laminated film can be performed in a conventionally known constant temperature room or the like.
Note that a laminated film that has been subjected to this heat treatment and a laminated film that has not been heat-treated can be distinguished by, for example, analyzing the cured state of the adhesives of both films.

≪Packaging body≫
The package of this embodiment is obtained by bag-making the film for package 1 of this embodiment. Examples of the package include bags made by heat-sealing the sealing layers 36 of the package film 1 together.
The form of the package includes, for example, a folding bag, a three-sided sealed bag, a four-sided sealed bag, a gusset bag, a stand bag, and a bag with a zipper.
For example, the package includes a container body having an opening and a lid made of the package film 1, and a sealing layer 36 is brought into contact with the periphery of the opening of the container body, and the package film 1 An example of this is a container that is heat-sealed to the container body. The material of the container body in this case is not particularly limited, and examples thereof include PET, paper, and the like.

As explained above, according to the film for packaging 1 of the present embodiment, the crystal water contained in the zeolite is appropriately released into the interior of the packaging, and it is easy to prevent the surface of the food contained in the packaging from burning. . Therefore, deterioration in food quality can be easily suppressed. In addition, the packaging film 1 adsorbs excess water present inside the packaging, making it easy to maintain the original texture of the food.
Moreover, according to the package made from the packaging film 1, unlike a moisture absorbent such as silica gel, moisture is not released all at once, but the mechanism gradually supplies an appropriate amount of moisture. It is possible to control variations in heating conditions in a microwave oven (variations due to the type, size, shape, etc. of the food being stored). That is, according to the package formed from the package film 1, overheating of the stored food can be suppressed.
Furthermore, according to the package formed from the package film 1, it is possible to suppress deterioration of the original texture of the food due to moisture released by heating penetrating into the food.
In addition, according to the package formed from the package film 1, it is possible to prevent moisture released by heating from adhering to the inside of the package and deteriorating the appearance of the package.

[Second embodiment]
A film for packaging according to a second embodiment of the present invention will be described with reference to the drawings.
The packaging film 2 shown in FIG. 2 has a water vapor barrier material 22 and a sealant material 30 laminated in this order. That is, the packaging film 2 includes a water vapor barrier material 22 and a sealant material 30 located on one surface of the water vapor barrier material 22.
This embodiment differs from the first embodiment in that the water vapor barrier material 22 also serves as a base material.

The water vapor barrier material 22 is a material that serves both as the base material 10 and the water vapor barrier material 20 in the first embodiment.
Examples of the water vapor barrier material 22 include inorganic vapor-deposited films such as PET, OPP, CPP, HDPE, and MDPE, in which silica, alumina, or the like is vapor-deposited on a resin film similar to the base material 10 in the first embodiment. Among inorganic vapor-deposited films, silica-deposited films are preferred.
By using an inorganic vapor-deposited film as the water vapor barrier material 22, permeation of water vapor can be suppressed.
In addition, as the water vapor barrier material 22, a cyclic olefin copolymer (COC) can be used. By using COC as the water vapor barrier material 22, the effort of vapor depositing silica, alumina, etc. can be saved.
Examples of COC include ethylene cycloolefin copolymer obtained by copolymerizing norbornene and ethylene.

The thickness T ₂₂ of the water vapor barrier material 22 is the same as the thickness T ₁₀ of the base material 10 in the first embodiment.
As a method for manufacturing the packaging film 2, a conventionally known manufacturing method can be adopted. For example, an inorganic vapor-deposited film is obtained as the vapor barrier material 22, and the vapor barrier material 22 and the sealant material 30 are stacked so that the vapor-deposited surface of the vapor barrier material 22 and the laminate layer 32 are in contact with each other, and then heated while being pressed. There are several methods.

≪Packaging body≫
The package of this embodiment is made into a bag using the package film 2. Examples of the package include bags made by heat-sealing the sealing layers 36 of the package film 2 together. Examples of the form of the package include a folding bag, a three-sided sealed bag, a four-sided sealed bag, a gusset bag, and a stand bag.

According to this embodiment, since the packaging film can be made thinner, flexibility can be further improved.

[Other embodiments]
In the embodiments described above, the sealant material includes a laminate layer, but the present invention is not limited thereto, and the laminate layer may be omitted and the moisture absorption layer may also serve as the laminate layer. However, from the viewpoint of further improving the adhesiveness between the water vapor barrier material and the sealant material, it is preferable that the film for packaging includes a laminate layer.

EXAMPLES Hereinafter, the present invention will be explained with reference to Examples, but the present invention is not limited to the following Examples.
The materials used in this example are as follows.

[Materials used]
≪Base material≫
・OPP: Biaxially oriented polypropylene, Pylene OT (trade name), manufactured by Toyobo Co., Ltd.
・PET: Lumirror (product name), manufactured by Toray Film Processing Co., Ltd.

≪Water vapor barrier material≫
- Silica-deposited PET: Tech Barrier (registered trademark), manufactured by Mitsubishi Chemical Corporation.
・COC: Cyclic olefin copolymer, ethylene cycloolefin copolymer (compound name), APEL (registered trademark), manufactured by Mitsui Chemicals, Inc.

≪Sealant material≫
・PE: LLDPE, RIX (registered trademark), manufactured by Toyobo Co., Ltd.

≪Zeolite≫
- Zeolite: Zeolite, average particle diameter = 7 μm, SiO ₂ /Al ₂ O ₃ ratio = 10/90 to 90/10, crystal water amount = 216 mol.

≪Silica gel≫
- Type A silica gel: Toyota Silica Gel (product name), manufactured by Toyota Chemical Corporation.

[Examples 1 to 8, Comparative Examples 1 to 5]
Packaging films according to the configurations of Examples 1 to 8 and Comparative Examples 1 to 5 were produced by laminating the base material, water vapor barrier material, and sealant material shown in Table 1. The sealant material is formed by molding the constituent raw materials of each layer using a coextruder. Further, the base material, the water vapor barrier material, and the sealant material were stacked and dry laminated so that the laminate layer was in contact with the water vapor barrier material.
In Example 3, the water vapor barrier material also serves as the base material, and the COC of the water vapor barrier material is the outermost layer.
In addition, "-" in the table indicates that the material is not included.

[Evaluation method]
A flat bag of 130 mm x 170 mm was produced using the packaging film obtained in each example.
Next, 60 g of french fries (salt content: 2% by mass) was placed in the flat bag, sealed, and cooked in a microwave oven (600 W, RE-S120, manufactured by Sharp Corporation) for 3 minutes.

<Evaluation of food quality>
After cooking, the flat bag was opened, and the presence or absence of burnt appearance on the surface of the french fries was visually confirmed, and five panelists scored them according to the following criteria. The average value of the scoring results of the five panelists was calculated, and the quality of the food was evaluated according to the following evaluation criteria. The results are shown in Table 1.
"Evaluation criteria"
0 points: No charring is observed.
1 point: Slight occurrence of charring is observed.
2 points: Burning is clearly observed.
"Evaluation criteria"
○: Average score is less than 1 point.
△: Average score is 1 point or more and less than 1.5 points.
×: Average score is 1.5 points or more.

<Evaluation of food texture>
After cooking, the flat bag was opened, the fries were eaten, and five panelists scored them according to the following criteria. The average value of the scoring results of the five panelists was calculated, and the texture of the food was evaluated according to the following evaluation criteria. The results are shown in Table 1.
"Evaluation criteria"
0 points: The original texture of the food is maintained.
1 point: There is a slight sense of moisture absorption in the food.
2 points: Moisture absorption is clearly felt in the food.
"Evaluation criteria"
○: Average score is less than 1 point.
△: Average score is 1 point or more and less than 1.5 points.
×: Average score is 1.5 points or more.

<Evaluation of packaging condition>
The ease with which the inner layers (sealing layers) can be peeled off from each other when opening the flat bag after heating and the appearance of the flat bag after heating were checked, and five panelists scored them according to the following criteria. The average value of the scoring results of the five panelists was calculated, and the packaging condition was evaluated according to the following evaluation criteria. The results are shown in Table 1.
"Evaluation criteria"
0 points: The inner layers can be easily peeled off from each other, and no water droplets are attached to the inside of the package.
1 point: The inner layers are easy to peel off, but water droplets adhere to the inside of the package.
2 points: The inner layers are difficult to peel off from each other, and water droplets adhere to the inside of the package.
"Evaluation criteria"
○: Average score is less than 1 point.
△: Average score is 1 point or more and less than 1.5 points.
×: Average score is 1.5 points or more.

<Comprehensive evaluation>
Based on the evaluation results of the above-mentioned food quality evaluation, food texture evaluation, and packaging condition evaluation, the packaging film of each example was comprehensively evaluated according to the following evaluation criteria. Those with an overall evaluation of "○" or "△" were considered to have passed.
"Evaluation criteria"
○: All evaluation results are "○".
△: There is no “×” in the evaluation result, and there is “△” in the evaluation result.
×: There is an “×” in the evaluation result.

As shown in Table 1, the packages using the packaging films of Examples 1 to 8 to which the present invention was applied had an overall evaluation of "○" or "△", which suppressed the deterioration of food quality. Moreover, it was confirmed that the original texture of the food was maintained.
On the other hand, Comparative Example 1, which used a packaging film without a water vapor barrier material, was unable to block the permeation of moisture from the outside, and the food texture and packaging condition were evaluated as "x". In Comparative Examples 2 and 5, in which packaging films were used in which the moisture content of the sealant material was outside the range of the present invention, all evaluation results were "x".
In Comparative Example 3, in which a packaging film containing type A silica gel was used instead of zeolite, the release of water proceeded in a short period of time, causing adhesion and penetration of water into the french fries, resulting in poor food texture evaluation. and the evaluation of the packaging condition was "x".
In Comparative Example 4, which used a packaging film in which the SiO ₂ /Al ₂ O ₃ ratio was outside the range of the present invention and the moisture content of the sealant material was outside the range of the present invention, all evaluation results were " It was “x”.

From the above results, it was confirmed that by applying the present invention, deterioration in food quality can be suppressed and the original texture of food can be maintained.

1, 2 Film for packaging 10 Base materials 20, 22 Water vapor barrier material 30 Sealant material 32 Laminate layer 34 Moisture absorption layer 36 Seal layer

Claims (4)

comprising a water vapor barrier material and a sealant material located on one side of the water vapor barrier material,
The sealant material includes a moisture absorption layer containing zeolite and a sealing layer, and the moisture absorption layer and the sealing layer are located in this order from the water vapor barrier material side,
The zeolite has a molar ratio expressed by SiO ₂ /Al ₂ O ₃ of 2/98 or more and 50/50 or less,
A film for packaging, wherein the sealant material has a moisture content of 1% by mass or more. The film for packaging according to claim 1, wherein the sealant material has a moisture content of 30% by mass or less. The sealant material further includes a laminate layer, and from the water vapor barrier material side,
The film for packaging according to claim 1 or 2, wherein the laminate layer, the moisture absorbing layer, and the sealing layer are located in this order. A package made of the film for a package according to any one of claims 1 to 3.

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