JP2023167822A - Laminate film and package - Google Patents

Abstract

To provide a laminate film having an easy peel layer which prevents whitening and deterioration in oxygen barrier properties even after performing heat treatment, has heat resistance and to which liquid generated from food products is hardly adhered and to provide a package using the laminate film.SOLUTION: There is provided a laminate film comprising at least an easy peel layer and an oxygen barrier layer, wherein the easy peel layer contains a propylene-based polymer having a melting point of 130°C or more, the surface roughness Rsm of the easy peel layer on the side opposite to the oxygen barrier layer side is 80 to 800 μm, the oxygen barrier layer contains a polyamide having an aromatic ring, immediately after retorting the laminate film at a temperature of 121°C for 30 minutes, the oxygen permeation amount of the laminate film is 100 cc/(m2 day atm) or less under the conditions of a temperature of 23°C and a relative humidity of 60%, and the ratio of the thickness of the oxygen barrier layer to the thickness of the laminate film is 60% or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a laminated film and a package.

From the standpoint of improving the quality of life in an aging society and securing lifelines in the event of a disaster, there is a need for retort food that can be stored at room temperature for a long period of time. Retort food refers to food that has been sterilized by retort (pressurized heating).Products that have been sterilized by retort can be made commercially sterile, allowing them to be distributed at room temperature.

A film for retort food packaging includes, for example, a multilayer polyamide layer including two or more polyamide layers via an adhesive layer, a gas barrier layer, an adhesive layer, and a sealant layer, which are arranged in this order. Various films such as laminated composite films (for example, Patent Documents 1 and 2) have been proposed.

Packaging materials used for packaging retort foods and the like are required to have oxygen barrier properties that prevent oxygen from permeating in order to maintain quality such as taste and freshness of the food.

Furthermore, various foods, including processed meat products such as ham, sausages, and bacon, are distributed in vacuum packaging.
In vacuum packaging, for example, a bottom material and a lid material made of resin film are used, the item to be packaged (food) is sandwiched between the lid material and the bottom material, and after vacuuming the area that will become the storage area, the lid material is removed. The object to be packaged is packaged by heating and sealing the bottom material. As the bottom material, a material in which a recessed portion is formed to constitute a storage section for the packaged item may be used. In that case, the item to be packaged is placed in a recess in the bottom material, the item is sandwiched between the lid material and the bottom material, and the inside of the storage section formed by the lid material and the bottom material is placed in the recess. After evacuating the material, the peripheral edges of the lid material and bottom material are heat-sealed into a frame shape, thereby packaging the item. A resin film suitable for constructing a package for such uses has been disclosed (see Patent Document 3).

Japanese Patent Application Publication No. 3-136851 Japanese Patent Application Publication No. 3-138149 Japanese Patent Application Publication No. 2016-222259

In conventional resin films, retort-resistant EVOH is used as a barrier material that has retort resistance, but because of its low hot water resistance, there has been a problem that whitening of the resin film and a decrease in barrier properties occur after retorting.
On the other hand, it is not certain whether the resin films disclosed in Patent Documents 1 and 2 have improved such problems.

A package produced by vacuum packaging food is usually sterilized, for example, by heat treatment in boiling water or by spraying high-temperature steam before shipping. Moreover, after such a package reaches a consumer as a product, it may be heat-treated in boiling water and made edible. Moreover, such a package is required to have easy peelability so that the food can be easily taken out. That is, in a resin film for forming a package for vacuum packaging of foods, it is desirable that at least one of the outermost layers, the easy-peel layer, has heat resistance.

Here, in a package manufactured by vacuum packaging food, there is a problem in that liquid generated from the food adheres to the easy peel layer, deteriorating the appearance of the vacuum package.
On the other hand, it is unclear whether the resin film disclosed in Patent Document 3 has improved this problem.

The present invention provides a laminated film having an easy-peel layer that suppresses whitening and deterioration of oxygen barrier properties even when subjected to heat treatment, has heat resistance, and is resistant to adhesion of liquids generated from foods; An object of the present invention is to provide a package using a laminated film.

In order to solve the above problems, the present invention employs the following configuration.
[1]. A laminated film comprising at least an easy-peel layer and an oxygen barrier layer, wherein the easy-peel layer contains a propylene polymer having a melting point of 130° C. or higher, and the easy-peel layer is opposite to the oxygen barrier layer side. The surface roughness Rsm of the side surface is 80 to 800 μm, the oxygen barrier layer includes polyamide having an aromatic ring, and immediately after the laminated film is retorted for 30 minutes at a temperature of 121° C. The amount of oxygen permeation of the laminated film measured in accordance with ASTM D3985 under the conditions of 23° C. and 60% relative humidity is 100 cc/(m ² ·day · atm) or less, and the thickness of the laminated film is A laminated film, wherein the ratio of the thickness of the oxygen barrier layer to the thickness of the oxygen barrier layer is 60% or less.

[2]. A laminated film comprising at least an easy peel layer and an oxygen barrier layer, the easy peel layer containing a propylene polymer having a melting point of 130° C. or higher and an anti-blocking agent, and the easy peel layer containing the anti-blocking agent. The ratio of the content of the anti-blocking agent to 100 parts by mass of the total content of components other than the blocking agent is 0.1 parts by mass or more, the oxygen barrier layer contains a polyamide having an aromatic ring, and the Immediately after the laminated film was subjected to retort treatment at a temperature of 121°C for 30 minutes, the amount of oxygen permeation of the laminated film was measured in accordance with ASTM D3985 at a temperature of 23°C and a relative humidity of 60%. /(m ² ·day · atm) or less, and the ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film is 60% or less.

[3]. The laminated film according to [1] or [2], wherein the laminated film further includes an intermediate layer adjacent to the oxygen barrier layer and on the easy peel layer side or the opposite side thereof.
[4]. The laminated film according to any one of [1] to [3], wherein the laminated film further includes a water vapor barrier layer, and the water vapor barrier layer contains a propylene polymer having a melting point of 130° C. or higher.
[5]. The easy-peel layer further contains an ethylene polymer, and in the easy-peel layer, the content of the propylene-based polymer is 60 to 80% by mass with respect to the total mass of the easy-peel layer, and the The laminate according to any one of [1] to [4], wherein in the easy-peel layer, the content of the ethylene polymer is 19 to 39% by mass with respect to the total mass of the easy-peel layer. film.

[6]. The laminated film further includes an outer layer as the outermost layer on the opposite side from the easy peel layer, and the outer layer contains a propylene polymer, and the propylene polymer is propylene alone having a melting point of 130° C. or higher. one or both of a polymer and a propylene-ethylene copolymer having a melting point of 130° C. or higher, and in the outer layer, the content ratio of the propylene-based polymer to the total mass of the outer layer is The laminated film according to any one of [1] to [5], which has a content of 90% by mass or more.
[7]. The laminate film according to [5], wherein the ethylene polymer included in the easy peel layer is low density polyethylene with a melting point of 120°C or lower.
[8]. The laminated film according to [5], wherein the ethylene polymer included in the easy peel layer is low density polyethylene having a density of 0.940 or less.

[9]. The laminated film according to [4], wherein the water vapor barrier layer has a melt tension of 0.2 g or more.
[10]. The laminated film according to [4], wherein the water vapor barrier layer contains one type of the propylene-based polymer, or contains two or more types of the propylene-based polymers having different melt tensions.
[11]. The laminated film according to [3], wherein the intermediate layer contains polyamide having no aromatic ring.

[12]. The laminated film according to any one of [1] to [11], wherein the laminated film has a haze of 20% or less.
[13]. The laminated film according to any one of [1] to [12], wherein the laminated film is for packaging retort food.
[14]. A package comprising the laminated film according to any one of [1] to [13].

According to the present invention, even if heat treatment is performed, whitening and deterioration of oxygen barrier properties are suppressed, and the laminated film is equipped with an easy-peel layer that is heat resistant and to which liquids generated from foods are difficult to adhere. , a package using the laminated film is provided.

1 is a cross-sectional view schematically showing an example of a laminated film according to an embodiment of the present invention. It is a sectional view showing typically another example of the laminated film concerning one embodiment of the present invention. FIG. 1 is a cross-sectional view schematically showing an example of a package according to an embodiment of the present invention.

<<Laminated film>>
A laminated film according to an embodiment of the present invention (a laminated film provided with an easy peel layer of the first embodiment described below) is a laminated film provided with at least an easy peel layer and an oxygen barrier layer, and wherein the easy peel layer contains a propylene-based polymer with a melting point of 130° C. or higher, and the surface roughness Rsm of the surface (sealing surface) opposite to the oxygen barrier layer side of the easy peel layer is 80 to 800 μm; Immediately after the oxygen barrier layer contains a polyamide having an aromatic ring and the laminated film is retorted at a temperature of 121°C for 30 minutes, the film is processed under conditions of a temperature of 23°C and a relative humidity of 60% in accordance with ASTM D3985. The amount of oxygen permeation of the laminated film measured by the method is 100 cc/(m ² ·day · atm) or less, and the ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film is 60% or less. It is.

In the laminated film of this embodiment, the easy peel layer contains a propylene polymer having a melting point of 130° C. or higher, and has heat resistance. Therefore, a package obtained by sealing the easy peel layer and another film using the laminated film of this embodiment also has heat resistance. Since the easy-peel layer has heat resistance, the packaging body can suppress fusion between the surfaces of the easy-peel layers in the laminated film even when subjected to heat treatment (for example, boiling in boiling water). . Further, even when heat-treated in this manner, a decrease in peel strength (in other words, seal strength) of the seal portion is suppressed. Therefore, for example, even if an impact is applied to the package after heat treatment, peeling of the seal portion, so-called seal removal, is suppressed.

In the laminated film of the present embodiment, the surface roughness Rsm of the surface opposite to the oxygen barrier layer side of the easy peel layer is 80 to 800 μm, so that the liquid generated from the food is transferred to the easy peel layer. becomes difficult to adhere to. Therefore, the package obtained using the laminated film of this embodiment also has the effect that the liquid generated from the food product is difficult to adhere to the easy peel layer.

In this specification, the surface roughness Rsm of the sheet surface is a value measured in accordance with JIS B 0601, not only in the case of the easy peel layer.

Since the oxygen barrier layer of the laminated film of this embodiment contains polyamide having an aromatic ring, the laminated film or a package manufactured using the same can be subjected to various types of treatment including retort treatment. Even if heat treatment is performed, whitening of the laminated film or package and a decrease in oxygen barrier properties are suppressed.

The laminated film of the present embodiment has the above-mentioned properties, which were measured in accordance with ASTM D3985 at a temperature of 23°C and a relative humidity of 60% immediately after the laminated film was retorted at a temperature of 121°C for 30 minutes. By setting the oxygen permeation amount of the laminated film to 100 cc/(m ² ·day · atm) or less, the packaged contents can be stored for a long period of time while suppressing deterioration.

In the laminated film of this embodiment, the ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film is 60% or less, so that foaming during film extrusion is suppressed.

The laminated film of this embodiment is suitable for vacuum packaging foods. Therefore, the packaging body obtained by vacuum packaging food products using the laminated film of this embodiment can suppress the deterioration of oxygen barrier properties even when subjected to various heat treatments including retort treatment, and can be easily packaged. Peelability is maintained.
The laminated film of this embodiment maintains its properties well even when subjected to various heat treatments as described above, and is therefore suitable for packaging retort food.

As described above, the laminated film of this embodiment has excellent properties as a resin film constituting a package for heat treatment.

Further, a laminated film according to another embodiment of the present invention (a laminated film provided with an easy peel layer of a second embodiment described below) is a laminated film provided with at least an easy peel layer and an oxygen barrier layer, The easy peel layer contains a propylene polymer having a melting point of 130° C. or higher and an anti-blocking agent, and in the easy peel layer, the anti-blocking agent is added to the total content of 100 parts by mass of components other than the anti-blocking agent. The content ratio of The amount of oxygen permeation of the laminated film measured in accordance with ASTM D3985 under the conditions of 23° C. and 60% relative humidity is 100 cc/(m ² ·day · atm) or less, and the thickness of the laminated film is The ratio of the thickness of the oxygen barrier layer to the thickness is 60% or less.

In the laminated film of the present embodiment, the easy-peel layer contains an anti-blocking agent in addition to a propylene-based polymer having a melting point of 130° C. or higher, and the easy-peel layer contains a total of components other than the anti-blocking agent. When the content of the anti-blocking agent is 0.1 parts by mass or more with respect to 100 parts by mass, liquid generated from the food becomes difficult to adhere to the easy-peel layer. Therefore, the package obtained using the laminated film of this embodiment also has the effect that the liquid generated from the food product is difficult to adhere to the easy peel layer.

As described above, the laminated film of this embodiment has excellent properties as a resin film constituting a package for heat treatment.

Hereinafter, the present invention will be described in detail with reference to the drawings. Note that in the drawings used in the following explanation, important parts may be shown enlarged for convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component are the same as in reality. Not necessarily.

FIG. 1 is a cross-sectional view schematically showing an example of the laminated film 1 of this embodiment.
The laminated film 1 shown here is constructed by laminating an easy peel layer 11, an oxygen barrier layer 13, and an outer layer 15 in this order in the thickness direction. The laminated film 1 further includes an intermediate layer 14 adjacent to the oxygen barrier layer 13 and on the outer layer 15 side. The laminated film 1 further includes a water vapor barrier layer 12 between the easy peel layer 11 and the oxygen barrier layer 13. The laminated film 1 further includes an adhesive layer 16 (herein sometimes referred to as "first adhesive layer 161") between the water vapor barrier layer 12 and the oxygen barrier layer 13, and an intermediate layer 14. An adhesive layer 16 (herein sometimes referred to as "second adhesive layer 162") is provided between the outer layer 15 and the adhesive layer 16 .
That is, the laminated film 1 includes an easy peel layer 11, a water vapor barrier layer 12, an adhesive layer 16 (first adhesive layer 161), an oxygen barrier layer 13, an intermediate layer 14, an adhesive layer 16 (second adhesive layer 162), and an outer layer 15. are laminated in this order in the thickness direction.

One surface 11b of the easy-peel layer 11 (the surface opposite to the water vapor barrier layer 12 side, sometimes referred to as the "second surface" in this specification) is one of the outermost surfaces (the main surface) of the laminated film 1. In the specification, this is the exposed surface.
The package can be made by heat-sealing the laminated films 1 together at the easy-peel layer 11 therein, or by heat-sealing the laminated film 1 with another film or sheet at the easy-peel layer 11 therein. Can be configured.
The second surface 11b of the easy-peel layer 11 serves as a sealing surface between the easy-peel layers 11 or with another film or sheet.

When the easy-peel layer 11 is the easy-peel layer of the first embodiment described below, the surface roughness Rsm of the second surface 11b of the easy-peel layer 11 is 80 to 800 μm.
When the easy-peel layer 11 is the easy-peel layer of the second embodiment described below, the easy-peel layer 11 contains not only a propylene-based polymer having a melting point of 130° C. or higher but also an anti-blocking agent, and the easy-peel layer 11 In this case, the ratio of the content of the anti-blocking agent to 100 parts by mass of the total content of components other than the anti-blocking agent is 0.1 part by mass or more.

One surface 15a of the outer layer 15 (the surface opposite to the intermediate layer 14 side, sometimes referred to as "first surface" in this specification) is the other outermost surface of the laminated film 1 (in this specification, is the exposed surface (sometimes referred to as the "first surface") 1a.

In the laminated film 1, the adhesive layer 16 (first adhesive layer 161) disposed between the water vapor barrier layer 12 and the oxygen barrier layer 13 adheres the water vapor barrier layer 12 and the oxygen barrier layer 13, and forms an intermediate layer. An adhesive layer 16 (second adhesive layer 162) disposed between intermediate layer 14 and outer layer 15 adheres intermediate layer 14 and outer layer 15.
These two adhesive layers 16 (first adhesive layer 161 and second adhesive layer 162) may be the same or different.

The laminated film of this embodiment is not limited to the laminated film 1, and some configurations may be changed, deleted, or added to the laminated film 1 without departing from the spirit of the present invention. .

For example, the laminated film 1 includes the intermediate layer 14 on the outer layer 15 side adjacent to the oxygen barrier layer 13, but the laminated film of this embodiment has the intermediate layer 14 adjacent to the oxygen barrier layer 13 on the water vapor barrier layer side. It may also include an intermediate layer. As long as the laminated film of this embodiment includes an intermediate layer adjacent to the oxygen barrier layer, the intermediate layer can be disposed either on the outer layer side of the oxygen barrier layer or on the water vapor barrier layer side. By being prepared, the effects obtained will be greater.

FIG. 2 is a cross-sectional view schematically showing another example of the laminated film of this embodiment.
In the figures after FIG. 2, the same components as those shown in the already explained figures are given the same reference numerals as in the already explained figures, and detailed explanation thereof will be omitted.
The laminated film 2 shown here is constructed by laminating an easy peel layer 11, an oxygen barrier layer 13, and an outer layer 15 in this order in the thickness direction. The laminated film 2 further includes an intermediate layer 14 adjacent to the oxygen barrier layer 13 and on the easy peel layer 11 side. The laminated film 2 further includes a water vapor barrier layer 12 between the easy peel layer 11 and the intermediate layer 14. The laminated film 2 further includes an adhesive layer 16 (herein sometimes referred to as "first adhesive layer 161") between the water vapor barrier layer 12 and the intermediate layer 14, and an oxygen barrier layer 13. An adhesive layer 16 (herein sometimes referred to as "second adhesive layer 162") is provided between the outer layer 15 and the adhesive layer 16 .
That is, the laminated film 2 includes an easy peel layer 11, a water vapor barrier layer 12, an adhesive layer 16 (first adhesive layer 161), an intermediate layer 14, an oxygen barrier layer 13, an adhesive layer 16 (second adhesive layer 162), and an outer layer 15. are laminated in this order in the thickness direction.

Laminated film 2 is the same as laminated film 1 except that the stacking order (in other words, the arrangement positions) of oxygen barrier layer 13 and intermediate layer 14 is reversed.

For example, the laminated films 1 and 2 include an easy peel layer 11, a water vapor barrier layer 12, a first adhesive layer 161, an oxygen barrier layer 13, an intermediate layer 14, a second adhesive layer 162, and an outer layer 15. The laminated film of this embodiment may include other layers that do not correspond to any of these layers. However, the other layer is not the outermost layer of the laminated film of this embodiment (in other words, in the laminated film of this embodiment, the other layer is disposed between the easy peel layer and the outer layer). ) is preferred.

Hereinafter, the laminated film of this embodiment will be explained in more detail.

<Easy peel layer of first embodiment>
The easy peel layer of the first embodiment (the easy peel layer 11 in the laminated film 1 shown in FIG. 1 and the laminated film 2 shown in FIG. 2) is an easy peel type sealant layer.
The easy-peel layer is one of the outermost layers of the laminated film, and is disposed at the outermost one in the lamination direction of each layer constituting the laminated film.

The easy peel layer preferably has transparency.

The easy peel layer contains a propylene polymer having a melting point of 130° C. or higher and has heat resistance.
As used herein, the term "propylene polymer" means a polymer (resin) having at least a structural unit derived from propylene, and a homopolypropylene (propylene homopolymer) having only a structural unit derived from propylene. , hPP), or a propylene-based copolymer having a structural unit derived from propylene and a structural unit derived from a monomer other than propylene.

Examples of the propylene copolymer contained in the easy peel layer include propylene-ethylene random copolymer (also known as polypropylene random copolymer, rPP), propylene-ethylene block copolymer (also known as polypropylene block copolymer, bPP), etc. Examples include propylene-ethylene copolymers.

The melting point of the propylene polymer contained in the easy peel layer is more preferably 140°C or higher, and may be either 145°C or higher or 150°C or higher. The higher the melting point of the propylene polymer, the more the heat resistance of the easy peel layer improves.
The upper limit of the melting point of the propylene polymer contained in the easy peel layer is not particularly limited. For example, the propylene polymer having a melting point of 170° C. or lower is easily available.

The easy-peel layer may contain only one type of propylene-based polymer, or may include two or more types. If there are two or more types, the combination and ratio thereof may be arbitrary depending on the purpose. can be selected.

The easy-peel layer preferably contains one or both of homopolypropylene (propylene homopolymer, hPP) and a propylene-ethylene copolymer as the propylene-based polymer, and has a melting point of any one of the above-mentioned melting points. It is more preferable to include one or both of homopolypropylene (propylene homopolymer, hPP) having a melting point of It may contain either or both of homopolypropylene (propylene homopolymer, hPP) having a melting point of 130 to 170°C. The higher the melting point of the propylene polymer, the better the heat resistance of the easy peel layer.

Examples of the easy-peel layer include those exhibiting peelability due to cohesive failure.
Examples of the easy-peel layer exhibiting peelability due to cohesive failure include those containing two types of incompatible polyolefins.

The surface roughness Rsm of the sealing surface of the easy peel layer is 80 to 800 μm. The surface roughness Rsm of the sealing surface of the easy peel layer is preferably 85 to 795 μm, more preferably 90 to 790 μm, and even more preferably 95 to 785 μm. By setting the surface roughness Rsm of the sealing surface of the easy-peel layer to be equal to or greater than the above lower limit, it becomes difficult for liquid generated from food to adhere to the easy-peel layer. By setting the surface roughness Rsm of the sealing surface of the easy-peel layer to be less than or equal to the upper limit above, it is possible to suppress winding misalignment when the raw film obtained by winding the laminated film with the easy-peel layer is transported for 600 km. be able to.

The surface roughness Rsm of the sealing surface of the easy-peel layer is determined, for example, by adding an anti-blocking agent to the easy-peel layer, and calculating the amount of the anti-blocking agent based on 100 parts by mass of the total content of components other than the anti-blocking agent in the easy-peel layer. It can be more easily adjusted by adjusting the content ratio.
The surface roughness Rsm of the sealing surface of the easy-peel layer can be determined, for example, by bringing a heated press plate whose surface condition has been adjusted into contact with the surface of the easy-peel layer that has been formed in advance, and heating the easy-peel layer with the press plate. The adjustment can be made more easily by applying pressure and transferring the surface condition of the press plate to the surface of the easy peel layer.

It is preferable that the easy peel layer further contains an ethylene polymer. An easy-peel layer containing a propylene-based polymer and an ethylene-based polymer is suitable because it exhibits releasability due to cohesive failure.

As used herein, "ethylene polymer" means a polymer (resin) having at least a structural unit derived from ethylene, and a polyethylene (ethylene homopolymer) having only a structural unit derived from ethylene. ) or an ethylene copolymer having a structural unit derived from ethylene and a structural unit derived from a monomer other than ethylene and propylene.

Examples of the polyethylene included in the easy peel layer include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), metallocene catalyst linear low density polyethylene (mLLDPE), medium density polyethylene (MDPE), and high density polyethylene. Examples include polyethylene (HDPE).
Both linear low-density polyethylene (LLDPE) and metallocene-catalyzed linear low-density polyethylene (mLLDPE) are types of low-density polyethylene (LDPE).

In this specification, the density of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and metallocene-catalyzed linear low-density polyethylene (mLLDPE) is 0.910 g/cm ³ or more, 0.940 g/cm Less than ³ .
Further, the density of medium density polyethylene (MDPE) is 0.940 g/cm ³ or more and less than 0.950 g/cm ³ .
Further, the density of high-density polyethylene (HDPE) is 0.950 g/cm ³ or more.

Examples of the ethylene copolymer contained in the easy peel layer include ethylene-vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer (EMA), and ethylene-methyl methacrylate copolymer (EMMA). , ethylene-ethyl acrylate copolymer (EEA), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate-maleic anhydride copolymer (E- EA-MAH), ionomer resin (ION resin), etc.
The ionomer resin is, for example, a resin in which a copolymer of ethylene and a small amount of acrylic acid or methacrylic acid has an ionically cross-linked structure due to salt formation between the acid moiety and metal ions. can be mentioned.

The ethylene-based polymer contained in the easy-peel layer is preferably low-density polyethylene with a melting point of 120° C. or lower. This makes it possible to pack at a sealing temperature of 150° C. or lower, thereby minimizing the effects of heat on the contents.
The melting point of the ethylene polymer contained in the easy peel layer is preferably 90°C or more and 120°C or less, more preferably 95°C or more and 119°C or less, for example, 100°C or more and 118°C or less, and Good too. When the melting point of the ethylene polymer is equal to or higher than the lower limit, the heat resistance of the easy-peel layer is further improved. When the melting point of the ethylene polymer is equal to or lower than the upper limit, the low-temperature sealing properties of the film can be ensured.

The easy peel layer preferably contains polyethylene (PE) as the ethylene polymer, more preferably contains low density polyethylene (LDPE), and contains low density polyethylene having a density of 0.940/cm ³ or less. More preferably, it may contain low-density polyethylene having a density of 0.930 g/cm ³ or more and 0.940 g/cm ³ or less, for example. The higher the density of the ethylene polymer within the low density range, the better the heat resistance of the easy peel layer.

The easy peel layer may contain only the propylene polymer, or only the propylene polymer and the ethylene polymer (i.e., the propylene polymer, or the propylene polymer and ethylene polymer). The propylene polymer, or the propylene polymer and ethylene polymer, and components other than these (in this specification, "other components") (i.e., consisting of the propylene polymer and the other component, or the propylene polymer, the ethylene polymer, and the other component). component).

The other components contained in the easy peel layer are not particularly limited, and can be arbitrarily selected depending on the purpose, and may be, for example, either a resin component or a non-resin component.
The other component, which is a resin component, is a resin that does not fall under either the propylene polymer or the ethylene polymer.
The other component, which is a resin component, may be a homopolymer that is a polymer of one type of monomer, or a copolymer that is a polymer of two or more types of monomers.

Examples of the other non-resin components include additives known in the art.
Examples of the additives include antifogging agents, antiblocking agents, antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, thinners, thickeners, thermal stabilizers, lubricants, infrared absorbers, Examples include ultraviolet absorbers.

The easy peel layer may contain only one type of other components, or may include two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily determined depending on the purpose. You can choose.

Ratio of the total content (parts by mass) of the propylene-based polymer and the ethylene-based polymer to the total mass (parts by mass) of the easy-peel layer in the easy-peel layer (([Propylene-based polymer of the easy-peel layer Polymer content (mass parts)] + [ethylene polymer content (mass parts) of the easy-peel layer])/[total mass of the easy-peel layer (mass parts)] x 100) is 80 mass% It is preferably at least 90% by mass, more preferably at least 95% by mass, and may be, for example, at least 97% by mass or at least 99% by mass. When the ratio is greater than or equal to the lower limit, the easy-peel properties and heat resistance of the easy-peel layer are further improved.
On the other hand, the ratio is 100% by mass or less.
The ratio is usually the total content of the propylene polymer and the ethylene polymer relative to the total content (parts by mass) of components that do not vaporize at room temperature in the easy-peel layer forming composition described below. (parts by mass) (([Content of propylene polymer in the composition for forming an easy-peel layer (parts by mass)] + [Content of ethylene polymer in the composition for forming an easy-peel layer (parts by mass) ])/[Total content (parts by mass) of components that do not vaporize at room temperature of the composition for forming an easy-peel layer]×100).

When the easy peel layer does not contain the ethylene polymer, the content of the ethylene polymer in the easy peel layer is 0 parts by mass, and when the easy peel layer forming composition does not contain the ethylene polymer. The content of the ethylene polymer in the composition for forming an easy peel layer is 0 parts by mass.

As used herein, "normal temperature" means a temperature that is not particularly cooled or heated, that is, a normal temperature, and includes, for example, a temperature of 15 to 25°C.

The easy-peel layer containing the propylene-based polymer and the ethylene-based polymer may include, for example, the ratio of the content of the propylene-based polymer to the total mass of the easy-peel layer ([propylene in the easy-peel layer]). The content of the system polymer (parts by mass)]/[total mass of the easy-peel layer (parts by mass)] x 100) is 55 to 85% by mass, based on the total mass of the easy-peel layer in the easy-peel layer. The content ratio of the ethylene polymer ([content of ethylene polymer in easy peel layer (parts by mass)])/[total mass of easy peel layer (parts by mass)] x 100) is 15 to 45. % by mass of the easy-peel layer.
Among these, a preferable easy-peel layer containing the propylene-based polymer and ethylene-based polymer has a content ratio of the propylene-based polymer in the easy-peel layer of 60 to 60 to the total mass of the easy-peel layer. Examples include an easy-peel layer in which the content of the ethylene polymer is 80% by mass and the content of the ethylene polymer is 19 to 39% by mass with respect to the total mass of the easy-peel layer. An easy-peel layer that satisfies these conditions is superior in terms of easy-peelability and heat resistance.

The easy peel layer may be composed of one layer (single layer) or may be composed of two or more layers. When the easy peel layer consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.

In this specification, "the multiple layers may be the same or different from each other" means "all the layers may be the same or all the layers may be different", not only in the case of easy-peel layers. ``Multiple layers may be the same, or only some of the layers may be the same,'' and ``the layers are different from each other'' means ``at least one of the constituent materials and thickness of each layer is different from each other.'' means.

The thickness of the easy peel layer is preferably 5 to 35 μm, and may be, for example, 6 to 24 μm or 7 to 20 μm. When the thickness of the easy-peel layer is greater than or equal to the lower limit, the sealing strength of the easy-peel layer becomes appropriately high. When the thickness of the easy-peel layer is less than or equal to the upper limit, the easy-peelability and flexibility of the laminated film become higher. In addition, as the thickness of the easy-peel layer becomes thinner, the transparency of the package (for example, the bottom material, which will be described later) improves. Visual recognition becomes easier.
Here, the "thickness of the easy-peel layer" means the thickness of the entire easy-peel layer. For example, the thickness of an easy-peel layer consisting of multiple layers is the sum of all the layers that make up the easy-peel layer. means the thickness of

Using the laminated film, a package is prepared by the method described below, and the peel strength of the sealed portion of the package is measured at room temperature. Peelability can be evaluated. For example, the peel strength of the sealed portion at 25° C. shown below is one indicator of easy peelability.

[Peel strength of seal portion at 25°C]
When the temperature of the package obtained using the laminated film was adjusted to 25 ° C., and the peel strength (N/15 mm) of the seal part of the package in this state was measured in accordance with JIS Z 0238:1998. , the peel strength is preferably 2 to 9 N/15 mm. A package whose peel strength is equal to or less than the upper limit when the temperature of the package is adjusted to 25° C. can be easily opened when opening the intended package. A package whose peel strength is equal to or higher than the lower limit when the temperature of the package is adjusted to 25° C. can prevent unintended opening.
The peel strength is determined, for example, by the peel strength in a resin film comprising a 50 μm thick sealant layer comprising linear low density polyethylene (LLDPE), preferably a 50 μm thick sealant layer comprising linear low density polyethylene. Peel strength of a package obtained by heat-sealing the sealant layer and the easy-peel layer in the laminated film at a sealing temperature of 150°C, a sealing time of 2 seconds, and a sealing pressure of 0.5 MPa. It's okay.

In this specification, "opening the package" means opening the package due to peeling of the lid material and the bottom material, unless otherwise specified.

<Easy peel layer of second embodiment>
The easy-peel layer of the second embodiment will be described below, focusing on the differences from the easy-peel layer of the first embodiment, and descriptions of similar matters will be omitted.

The easy peel layer contains an anti-blocking agent in addition to a propylene polymer having a melting point of 130° C. or higher. Since the easy-peel layer contains the anti-blocking agent, liquid generated from food is less likely to adhere to the easy-peel layer.

Examples of the anti-blocking agent include natural silica, synthetic silica, and silicates. Examples of the shape of the anti-blocking agent include spherical, elliptical, and other irregular shapes.

The average particle diameter of the anti-blocking agent is preferably 0.5 to 20 μm, more preferably 0.6 to 19 μm, and even more preferably 0.7 to 18 μm. By setting the average particle diameter of the anti-blocking agent to be equal to or larger than the above lower limit, liquid generated from food becomes less likely to adhere to the easy-peel layer. By setting the average particle diameter of the anti-blocking agent to be less than or equal to the above upper limit, it is possible to further suppress winding misalignment when the raw film obtained by winding the laminated film provided with the easy-peel layer is transported for 600 km. can.

The easy-peel layer may contain only one kind of anti-blocking agent, or it may contain two or more kinds. If there are two or more kinds, the combination and ratio thereof can be arbitrarily selected depending on the purpose. can.

In the easy-peel layer, the content of the anti-blocking agent is 0.1 part by mass or more with respect to 100 parts by mass of the total content of components other than the anti-blocking agent. By setting the above ratio to 0.1 part by mass or more, liquid generated from food becomes difficult to adhere to the easy-peel layer.

In the easy peel layer, the content ratio of the anti-blocking agent to 100 parts by mass of the total content of components other than the anti-blocking agent is preferably 0.15 to 3.05 parts by mass, and 0.2 parts by mass. The amount is more preferably 3.0 parts by weight, and even more preferably 0.25 to 2.95 parts by weight. By setting the above-mentioned ratio to the above-mentioned upper limit value or more, the liquid generated from the food becomes less likely to adhere to the easy-peel layer. By setting the ratio to be equal to or less than the lower limit value, it is possible to further suppress winding misalignment when the original fabric obtained by winding up the laminated film provided with the easy-peel layer is transported for 600 km.

As described above, the easy-peel layer of the second embodiment contains not only a propylene-based polymer having a melting point of 130° C. or higher but also an anti-blocking agent, and the total content of components other than the anti-blocking agent in the easy-peel layer. It is essential that the content ratio of the anti-blocking agent to 100 parts by mass is 0.1 part by mass or more, and the surface roughness Rsm of the sealing surface of the easy-peel layer is 80 to 800 μm. However, it is the same as the easy-peel layer of the first embodiment described above, except that it is not essential.

The easy-peel layer of the second embodiment differs from the easy-peel layer of the first embodiment in that the surface roughness Rsm of the sealing surface is not necessarily 80 to 800 μm; The roughness Rsm may be 80 to 800 μm like the easy peel layer of the first embodiment. That is, the surface roughness Rsm of the sealing surface of the easy-peel layer of the second embodiment may be 80 to 800 μm, as in the case of the easy-peel layer of the first embodiment.

<Outer layer>
The outer layer (outer layer 15 in the laminated film 1 shown in FIG. 1 and the laminated film 2 shown in FIG. 2) has rigidity and is a layer for protecting layers other than the outer layer constituting the laminated film. .
The outer layer is the outermost layer on the side opposite to the easy-peel layer side of the laminated film, that is, the other outermost layer, and is disposed at the other outermost layer in the lamination direction of each layer constituting the laminated film.

It is preferable that the outer layer has transparency.

The outer layer may contain a propylene polymer.
The melting point of the propylene polymer contained in the outer layer is preferably 130°C or higher. Such an outer layer has heat resistance.
The propylene polymer contained in the outer layer may be the same as the propylene polymer contained in the easy peel layer described above.
The propylene polymer contained in the outer layer and the propylene polymer contained in the easy peel layer may be the same or different from each other.

The outer layer may contain only one type of propylene polymer, or may include two or more types, and in the case of two or more types, the combination and ratio thereof may be arbitrarily selected depending on the purpose. can.

The outer layer preferably contains one or both of homopolypropylene (propylene homopolymer, hPP) and propylene-ethylene copolymer as the propylene-based polymer, and has one of the melting points mentioned above. It is more preferable to include either one or both of homopolypropylene (propylene homopolymer, hPP) and a propylene-ethylene copolymer having one of the above-mentioned melting points. It may contain one or both of homopolypropylene (propylene homopolymer, hPP) and a propylene-ethylene copolymer having a melting point of 130 to 170°C. The higher the melting point of the propylene polymer, the better the heat resistance of the outer layer.

The outer layer may contain only the propylene-based polymer (that is, it may contain the propylene-based polymer), or may contain the propylene-based polymer and other components (in this specification, may also be referred to as "other components" (that is, may consist of the propylene-based polymer and the other components).

The other components contained in the outer layer are not particularly limited and can be arbitrarily selected depending on the purpose, and may be, for example, either a resin component or a non-resin component.
The other component which is a resin component is a resin other than the propylene polymer.
The other component, which is a resin component, may be a homopolymer that is a polymer of one type of monomer, or a copolymer that is a polymer of two or more types of monomers.

Examples of the other components that are non-resin components include the same additives mentioned above as other components included in the easy-peel layer.

The outer layer may contain only one type of other components, or may include two or more types, and in the case of two or more types, the combination and ratio thereof can be arbitrarily selected depending on the purpose. .

Ratio of the content (parts by mass) of the propylene polymer in the outer layer to the total mass (parts by mass) of the outer layer ([Content of propylene polymer in the outer layer (parts by mass)]/[Total mass of the outer layer (parts by mass)] Parts by mass)] x 100) is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, for example, 97% by mass or more, and 99% by mass or more. It may be more than % by mass. When the ratio is equal to or higher than the lower limit, the rigidity and heat resistance of the outer layer are further improved.
On the other hand, the ratio is 100% by mass or less.
The ratio is usually the ratio of the content (parts by mass) of the propylene polymer to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an outer layer, which will be described later. [Content of propylene-based polymer in the product (parts by mass)]/[Total content (parts by mass) of components that do not vaporize at room temperature of the composition for forming an outer layer]×100).
The propylene polymer that satisfies the ratio conditions may be either or both of homopolypropylene (propylene homopolymer, hPP) and propylene-ethylene copolymer.

As a more preferable example of the outer layer, the propylene polymer is either homopolypropylene (propylene homopolymer, hPP) with a melting point of 130° C. or higher, or propylene-ethylene copolymer with a melting point of 130° C. or higher. The outer layer contains one or both of the propylene homopolymer and the propylene-ethylene copolymer, and the total content of the propylene homopolymer and the propylene-ethylene copolymer is 90% by mass or more based on the total mass of the outer layer. It will be done.
In such an outer layer, the proportion is 100% by mass or less.
The ratio is usually the total content (mass parts) of the homopolypropylene and the propylene-ethylene copolymer relative to the total content (mass parts) of components that do not vaporize at room temperature in the outer layer forming composition described below. (parts)) (([Content of the homopolypropylene in the composition for forming an outer layer (parts by mass)] + [Content of the propylene-ethylene copolymer in the composition for forming an outer layer (parts by mass)]) / [Outer layer It is the same as the total content (parts by mass) of components that do not vaporize at room temperature of the forming composition] x 100).
When the outer layer does not contain the homopolypropylene, the content of the homopolypropylene in the outer layer is 0 parts by mass, and when the outer layer forming composition does not contain the homopolypropylene, the content of the homopolypropylene in the outer layer forming composition The amount is 0 parts by weight.
When the outer layer does not contain the propylene-ethylene copolymer, the content of the propylene-ethylene copolymer in the outer layer is 0 parts by mass, and when the outer layer-forming composition does not contain the propylene-ethylene copolymer. The content of the propylene-ethylene copolymer in the outer layer forming composition is 0 parts by mass.

The outer layer may consist of one layer (single layer) or may consist of two or more layers. When the outer layer is composed of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.

The thickness of the outer layer is preferably 15 to 70 μm, and may be, for example, 17.5 to 55 μm or 20 to 40 μm. When the thickness of the outer layer is greater than or equal to the lower limit, the outer layer has higher rigidity and heat resistance. When the thickness of the outer layer is equal to or less than the above upper limit, the flexibility of the laminated film becomes higher. In addition, as the thickness of the outer layer becomes thinner, the transparency of the package (e.g., the bottom material described below) improves, making it easier to see the stored items from the outside on the laminated film side (e.g., the bottom material side) of the package. becomes easier.
Here, the "thickness of the outer layer" means the thickness of the entire outer layer, and for example, the thickness of the outer layer consisting of multiple layers means the total thickness of all the layers constituting the outer layer.

◎Relationship between the easy-peel layer and the outer layer If the type of resin that is the main component differs greatly between the outer layer and the easy-peel layer of a resin film, the resin contained in the outer layer will change when the resin film is heat-treated. Curling may occur in the resin film due to the difference between the coefficient of thermal expansion of the resin film and the coefficient of thermal expansion of the resin included in the easy-peel layer. Therefore, in order to avoid this, it is conceivable that the outer layer also contains a propylene-based polymer, similar to the easy-peel layer.

When the outer layer and the easy-peel layer contain a propylene-based polymer, the occurrence of curling after heat treatment (for example, boiling in hot water) is suppressed. Therefore, a package obtained by sealing the easy-peel layer and other films using the laminated film of this embodiment also suffers from curling after heat treatment (for example, boiling in boiling water). is suppressed.

It is preferable that the melting point of the propylene polymer contained in the outer layer and the easy peel layer is 130° C. or higher. Such a laminated film has higher heat resistance.

The density (g/cm ³ ) of the propylene polymer contained in the outer layer is preferably 0.990 to 1.010 times that of the propylene polymer contained in the easy peel layer. More preferably, it is 994 to 1.006 times. Since the propylene polymer contained in the outer layer and the propylene polymer contained in the easy peel layer have such a relationship, curling is highly suppressed in the laminated film after heat treatment. In this specification, the propylene polymer contained in the outer layer that satisfies these conditions is referred to as a "propylene polymer (Z2)", and the propylene polymer contained in the easy peel layer is referred to as a "propylene polymer (Z2)". Polymer (Z1).

When the outer layer contains the propylene polymer (Z2) and the easy peel layer contains the propylene polymer (Z1), the proportion of the propylene polymer (Z2) in the outer layer relative to the total mass (parts by mass) of the outer layer. The content (parts by mass) of is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, for example, 97% by mass or more, and 99% by mass or more, and the total of the propylene polymer (Z1) and the ethylene polymer in the easy peel layer relative to the total mass (parts by mass) of the easy peel layer. The content (parts by mass) is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, for example, 97% by mass or more, and The content of the propylene polymer (Z1) in the easy-peel layer may be 60 to 80% by mass with respect to the total mass of the easy-peel layer. Preferably, the content of the ethylene polymer in the easy-peel layer is 19 to 39% by mass relative to the total mass of the easy-peel layer. Such a laminated film has a particularly high effect of suppressing the occurrence of curling after heat treatment, and has particularly excellent properties.

<Water vapor barrier layer>
The water vapor barrier layer (water vapor barrier layer 12 in the laminated film 1 shown in FIG. 1 and the laminated film 2 shown in FIG. 2) imparts water vapor barrier properties (characteristics that suppress water vapor permeation) to the laminated film. In a package obtained using such a laminated film, moisture infiltration from the outer layer side to the inside is suppressed. Furthermore, the water vapor barrier layer has a melt tension of 0.2 g or more, thereby imparting stable sealing strength to the package manufactured using the laminated film. In particular, the water vapor barrier layer 12 is placed adjacent to the easy peel layer (in the laminated film 1 shown in FIG. 1 and the laminated film 2 shown in FIG. 2, the water vapor barrier layer 12 is placed adjacent to the easy peel layer 11). ), the effect of the water vapor barrier layer in imparting stable sealing strength to the package becomes even higher.

The water vapor barrier layer preferably has transparency.

The water vapor barrier layer is preferably a resin layer containing a water vapor barrier resin having water vapor barrier properties.

Examples of the water vapor barrier resin include propylene polymers, ethylene polymers, and the like.

Examples of the propylene polymer contained in the water vapor barrier layer include homopolypropylene (propylene homopolymer, hPP), propylene copolymer, and the like.
Examples of the propylene copolymer contained in the water vapor barrier layer include propylene-ethylene random copolymer (also known as polypropylene random copolymer, rPP), propylene-ethylene block copolymer (also known as polypropylene block copolymer, bPP), etc. propylene-ethylene copolymers; propylene-(α-olefin) copolymers, and the like.

The melting point of the propylene polymer contained in the water vapor barrier layer is preferably 130°C or higher, and may be any one of 140°C or higher, 145°C or higher, or 150°C or higher. The higher the melting point of the propylene-based polymer, the more effective the water vapor barrier layer is in imparting stable seal strength to the package.
The upper limit of the melting point of the propylene polymer contained in the water vapor barrier layer is not particularly limited. For example, the propylene polymer having a melting point of 170° C. or lower is easily available.

Examples of the ethylene polymer contained in the water vapor barrier layer include polyethylene (ethylene homopolymer), ethylene copolymer, and the like.
Examples of the polyethylene contained in the water vapor barrier layer include low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE).
The ethylene copolymer contained in the water vapor barrier layer includes, for example, an ethylene-α olefin copolymer; an ethylene-cyclic olefin copolymer obtained by copolymerizing a cyclic olefin such as cyclopentadiene or norbornene; Vinyl acetate copolymer (EVA); partially saponified or completely saponified ethylene-vinyl acetate copolymer; ethylene-(meth)acrylic acid copolymer or its esterified or ionic crosslinked product; ethylene-(meth)acrylic Examples include acid-(meth)acrylic acid ester terpolymer; maleic anhydride-modified polyethylene; maleic anhydride-polyethylene copolymer.

In this specification, "(meth)acrylic acid" is a concept that includes both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid.

The water vapor barrier layer may contain only one type of component that exhibits water vapor barrier properties (for example, the above-mentioned water vapor barrier resin), or may include two or more types. The combination and ratio can be arbitrarily selected depending on the purpose.

The melt tension of the water vapor barrier layer can be adjusted, for example, by adjusting the type and content of the components contained in the water vapor barrier layer, such as the water vapor barrier resin.
The components contained in the water vapor barrier layer exhibit a unique melt tension depending on their type (in other words, they form a film or sheet having a unique melt tension). Content can be selected.

In order to increase the melt tension of the water vapor barrier layer, the water vapor barrier layer preferably contains, for example, a resin having branched chains, and more preferably contains a resin having many branched chains.

In particular, the water vapor barrier layer preferably contains a propylene polymer, either a propylene homopolymer with a melting point of 130° C. or higher, or a propylene copolymer with a melting point of 130° C. or higher. It is more preferable to contain either one or both of a propylene homopolymer having a melting point of 130°C or higher and a propylene-ethylene copolymer having a melting point of 130°C or higher. , more preferred.

For example, the water vapor barrier layer may contain one type of the propylene-based polymer, or may contain two or more types of the propylene-based polymers having different melt tensions. For example, when only one type of propylene polymer is selected, it may be difficult to set the melt tension of the water vapor barrier layer to a desired value. In that case, the melt tension of the water vapor barrier layer can be easily set by using two or more of the propylene polymers having different melt tensions together. That is, by using the propylene-based polymer with a lower melt tension and the propylene-based polymer with a higher melt tension in combination, taking their melt tensions into consideration, the melt tension of the water vapor barrier layer can be easily adjusted. It can be adjusted to For example, a preferable example of the propylene-based polymer having a high melt tension is metallocene-based high melt tension polypropylene (in other words, metallocene-catalyzed high melt tension polypropylene).

Here, a case has been described in which the propylene-based polymer is used to adjust the melt tension of the water vapor barrier layer, but the melt tension may be adjusted using a component other than the propylene-based polymer.

The melt tension of the water vapor barrier layer is preferably 0.2 g or more, and may be, for example, 0.3 g or more, 0.5 g or more, or 0.7 g or more. When the melt tension of the water vapor barrier layer is equal to or greater than the lower limit value, the effect of the water vapor barrier layer in imparting stable seal strength to the package becomes high.
The upper limit of the melt tension of the water vapor barrier layer is not particularly limited. For example, the melt tension of the water vapor barrier layer is preferably 1 g or less in terms of forming the water vapor barrier layer more easily.
In one embodiment, the melt tension of the water vapor barrier layer may be, for example, any of 0.2-1 g, 0.3-1 g, 0.5-1 g, and 0.7-1 g. However, these are examples of the melt tension of the water vapor barrier layer.

As used herein, "melt tension" means "melt tension at 230°C" unless otherwise specified. Melt tension can be measured using a capillograph in accordance with JIS K7199:1999.

The water vapor barrier layer containing the propylene polymer may contain only the propylene polymer (that is, it may consist of the propylene polymer), or the propylene polymer and It may contain other components (herein sometimes referred to as "other components") (i.e., it consists of the propylene polymer and the other components). good).

The other components contained in the water vapor barrier layer are not particularly limited, and can be arbitrarily selected depending on the purpose, and may be, for example, either a resin component or a non-resin component.
The other component which is a resin component is a resin other than the propylene polymer.
The other component, which is a resin component, may be a homopolymer that is a polymer of one type of monomer, or a copolymer that is a polymer of two or more types of monomers.

Examples of the other components that are non-resin components include the same additives mentioned above as other components included in the easy-peel layer.

The water vapor barrier layer may contain only one type of other components, or may include two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily determined depending on the purpose. You can choose.

When the water vapor barrier layer contains the propylene-based polymer, in the water vapor barrier layer, the ratio of the content (parts by mass) of the propylene-based polymer to the total mass (parts by mass) of the water vapor barrier layer The content of propylene polymer (parts by mass)]/[total mass of water vapor barrier layer (parts by mass)] x 100) is preferably 80% by mass or more, more preferably 90% by mass or more. , more preferably 95% by mass or more, and may be, for example, 97% by mass or more, or 99% by mass or more. When the ratio is equal to or greater than the lower limit, the effect of the water vapor barrier layer in imparting stable seal strength to the package becomes higher.
On the other hand, the ratio is 100% by mass or less.
The ratio is usually the ratio of the content (parts by mass) of the propylene polymer to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming a water vapor barrier layer (described later). The content of the propylene polymer in the layer-forming composition (parts by mass)]/[total content of components that do not vaporize at room temperature (parts by mass) in the composition for forming a water vapor barrier layer] x 100) be.

As an example of a more preferable water vapor barrier layer, the propylene polymer is homopolypropylene (propylene homopolymer, hPP) with a melting point of 130°C or higher, and a propylene-ethylene copolymer with a melting point of 130°C or higher. In the water vapor barrier layer, the total content of the propylene homopolymer and the propylene-ethylene copolymer is 90% by mass with respect to the total mass of the water vapor barrier layer. The water vapor barrier layer mentioned above can be mentioned.
In such a water vapor barrier layer, the proportion is 100% by mass or less.
The ratio is usually the total content of the homopolypropylene and the propylene-ethylene copolymer relative to the total content (parts by mass) of components that do not vaporize at room temperature in the water vapor barrier layer forming composition described below. (parts by mass) (([content of the homopolypropylene in the composition for forming a water vapor barrier layer (parts by mass)] + [content of the propylene-ethylene copolymer in the composition for forming a water vapor barrier layer (parts by mass) )])/[total content (parts by mass) of components that do not vaporize at room temperature of the composition for forming a water vapor barrier layer]×100).
When the water vapor barrier layer does not contain the homopolypropylene, the content of the homopolypropylene in the water vapor barrier layer is 0 parts by mass, and when the composition for forming a water vapor barrier layer does not contain the homopolypropylene, the content of the homopolypropylene in the water vapor barrier layer is 0 parts by mass. The content of the homopolypropylene in the composition is 0 parts by mass.
When the water vapor barrier layer does not contain the propylene-ethylene copolymer, the content of the propylene-ethylene copolymer in the water vapor barrier layer is 0 parts by mass, and the water vapor barrier layer forming composition does not contain the propylene-ethylene copolymer. When the composition does not contain a polymer, the content of the propylene-ethylene copolymer in the composition for forming a water vapor barrier layer is 0 parts by mass.

As another example of a more preferable water vapor barrier layer, the water vapor barrier layer contains one kind of the above propylene polymer, or contains two or more kinds of the above propylene polymers having different melt tensions, and in the water vapor barrier layer, the water vapor barrier layer contains the above propylene polymer. Examples include water vapor barrier layers in which the content of the propylene polymer is 90% by mass or more with respect to the total mass of the barrier layer.
In such a water vapor barrier layer, the proportion is 100% by mass or less.
The ratio is usually the ratio of the content (parts by mass) of the propylene polymer to the total content (parts by mass) of components that do not vaporize at room temperature in the water vapor barrier layer forming composition (([water vapor Content (parts by mass) of the propylene polymer in the composition for forming a barrier layer] / [Total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming a water vapor barrier layer] x 100 ), is the same as.
When the water vapor barrier layer includes one type of the propylene polymer, the "content (parts by mass) of the propylene polymer" refers to the content (parts by mass) of the one type of propylene polymer. be. When the water vapor barrier layer contains two or more of the propylene polymers having different melt tensions, "content (parts by mass) of the propylene polymer" refers to the content of the two or more propylene polymers. Total content (parts by mass).

The water vapor barrier layer may be composed of one layer (single layer) or may be composed of two or more layers. When the water vapor barrier layer is composed of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.

The thickness of the water vapor barrier layer is preferably 30 to 100 μm, and may be, for example, 35 to 90 μm or 40 to 60 μm. When the thickness of the water vapor barrier layer is equal to or greater than the lower limit, the strength of the water vapor barrier layer becomes higher. When the thickness of the water vapor barrier layer is less than or equal to the upper limit value, the flexibility of the water vapor barrier layer (laminated film) becomes higher. In addition, as the thickness of the water vapor barrier layer becomes thinner, the transparency of the package (for example, the bottom material described below) improves, so that stored items from the outside on the laminated film side (for example, the bottom material side) of the package improve. Visual recognition becomes easier.
Here, the "thickness of the water vapor barrier layer" means the thickness of the entire water vapor barrier layer. For example, the thickness of a water vapor barrier layer consisting of multiple layers is the total thickness of all the layers that make up the water vapor barrier layer. means the thickness of

<Oxygen barrier layer>
The oxygen barrier layer (the oxygen barrier layer 13 in the laminated film 1 shown in FIG. 1 and the laminated film 2 shown in FIG. 2) provides the laminated film with oxygen barrier properties (characteristics that suppress permeation of oxygen gas). In a package obtained using such a laminated film, the intrusion of oxygen into the interior from the outer layer side is suppressed.

It is preferable that the oxygen barrier layer has transparency.

The oxygen barrier layer contains polyamide having an aromatic ring (aromatic polyamide). As a result, even if the laminated film or a package manufactured using the same is subjected to various heat treatments such as retort treatment, whitening of the laminated film or package and a decrease in oxygen barrier properties are suppressed. Ru.

The aromatic polyamide included in the oxygen barrier layer may have aromatic rings only in its main chain, only in its side chains, or aromatic rings in its main chain and side chains. It may be included in both. Among these, it is preferable that the aromatic polyamide has an aromatic ring at least in its main chain.

As used herein, the term "main chain" refers to a chain structure formed by polymerization of monomers, unless otherwise specified. , the one with the longest chain length.

As the aromatic polyamide contained in the oxygen barrier layer, for example, a nylon salt obtained by the reaction of a cyclic lactam (a lactam having 3 or more ring members), an amino acid, or a diamine with a dicarboxylic acid can be homopolymerized or copolymerized. Examples include polyamides having aromatic rings obtained by polymerization.

Examples of the cyclic lactam include ε-caprolactam, ω-enantholactam, ω-laurolactam, α-pyrrolidone, α-piperidone, and the like.

Examples of the amino acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

Examples of the diamine forming the nylon salt include tetramethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2, Aliphatic amines such as 4-trimethylhexamethylene diamine and 2,4,4-trimethylhexamethylene diamine;
1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, isophoronediamine, piperazine, bis(4-aminocyclohexyl)methane, 2,2-bis-(4-aminocyclohexyl)propane, etc. alicyclic diamine;
An alicyclic diamine having a structure in which one or more hydrogen atoms bonded to carbon atoms constituting the alicyclic skeleton in the alicyclic diamine are substituted with groups other than hydrogen atoms. Diamine derivative;
Aromatic diamines such as meta-xylylene diamine, para-xylylene diamine, 1,4-phenylene diamine (also known as 1,4-diaminobenzene), and 1,3-phenylene diamine (also known as 1,3-diaminobenzene);
An aromatic diamine derivative having a structure in which one or more hydrogen atoms bonded to carbon atoms constituting the aromatic ring skeleton in the aromatic diamine are substituted with groups other than hydrogen atoms. etc.

Examples of the dicarboxylic acid that forms the nylon salt include glutaric acid (also known as 1,3-propanedicarboxylic acid), adipic acid (also known as 1,4-butanedicarboxylic acid), and pimelic acid (also known as 1,5-propanedicarboxylic acid). -pentanedicarboxylic acid), suberic acid (also known as 1,6-hexanedicarboxylic acid), azelaic acid (also known as 1,7-heptanedicarboxylic acid), sebacic acid (1,8-octanedicarboxylic acid), undecanedioic acid ( Aliphatic dicarboxylic acids such as 1,9-nonanedicarboxylic acid) and dodecanedioic acid (1,10-decanedicarboxylic acid);
Alicyclic dicarboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid;
An alicyclic dicarboxylic acid having a structure in which one or more hydrogen atoms bonded to carbon atoms constituting the aliphatic ring skeleton in the alicyclic dicarboxylic acid are substituted with groups other than hydrogen atoms. Group dicarboxylic acid derivatives;
Terephthalic acid (alias: 1,4-benzenedicarboxylic acid), Isophthalic acid (alias: 1,3-benzenedicarboxylic acid), 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid acid, 1,5-naphthalene dicarboxylic acid, 1,6-naphthalene dicarboxylic acid, 1,7-naphthalene dicarboxylic acid, 1,8-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, Aromatic dicarboxylic acids such as 2,7-naphthalene dicarboxylic acid;
An aromatic dicarboxylic acid having a structure in which one or more hydrogen atoms bonded to carbon atoms constituting the aromatic ring skeleton in the aromatic dicarboxylic acid are substituted with groups other than hydrogen atoms. Examples include acid derivatives.

However, when producing an aromatic polyamide, one or more selected from the group consisting of cyclic lactams, amino acids, diamines, and dicarboxylic acids having an aromatic ring skeleton are used.

Preferred aromatic polyamides included in the oxygen barrier layer include, for example, the following general formula (I):

（式中、ｎ_１は２以上の整数である。）
で表される化合物（本明細書においては、「メタキシリレンアジパミド」と称することがある）と、下記一般式（ＩＩ）：

(In the formula, _n1 is an integer of 2 or more.)
A compound represented by (herein sometimes referred to as "methaxylylene adipamide") and the following general formula (II):

（式中、ｎ_２は２以上の整数であり；Ｘ^１及びＸ^２は、それぞれ独立に置換基である。）で表される化合物（本明細書においては、「ポリアミド（ＩＩ）」と称することがある）が挙げられる。

(In the formula, n ₂ is an integer of 2 or more; X ¹ and X ² are each independently a substituent.) (In this specification, referred to as "polyamide (II)") ) can be mentioned.

In polyamide (II), X ¹ and X ² are each independently a substituent, that is, a group other than a hydrogen atom. In this specification, the term "group" includes not only an atomic group having a structure in which a plurality of atoms are bonded, but also a single atom.
X ¹ and X ² are not particularly limited. All of the n ₂ X ¹ 's may be the same, all of them may be different, or only some of them may be the same. n ₂ X ² 's may all be the same, all different, or only some of them may be the same.
The bonding positions of X ¹ and X ² to the benzene ring skeleton are not particularly limited, and each may be at any of the four carbon atoms in the benzene ring skeleton. The bonding positions of n ₂ X ¹ to the benzene ring skeleton are not particularly limited, and may all be the same, all different, or only a portion may be the same. The bonding positions of n ₂ X ² to the benzene ring skeleton are not particularly limited, and may all be the same, all different, or only a portion may be the same.

The oxygen barrier layer may contain only one kind of aromatic polyamide, or may contain two or more kinds. When there are two or more kinds, the combination and ratio thereof can be arbitrarily determined depending on the purpose. You can choose.

The aromatic polyamide included in the oxygen barrier layer is preferably the metaxylylene adipamide (the compound represented by the general formula (I)). The metaxylylene adipamide can be produced, for example, by copolymerizing metaxylylene diamine and adipic acid.

The oxygen barrier layer may contain only aromatic polyamide (that is, may be made of aromatic polyamide), or may contain aromatic polyamide and other components (in this specification, , sometimes referred to as "other components") (that is, it may consist of an aromatic polyamide and the other components).

The other components contained in the oxygen barrier layer are not particularly limited and can be arbitrarily selected depending on the purpose, and may be, for example, either a resin component or a non-resin component.
The other component, which is a resin component, is a resin other than aromatic polyamide, and may be, for example, a non-aromatic polyamide described below.
The other component, which is a resin component, may be a homopolymer that is a polymer of one type of monomer, or a copolymer that is a polymer of two or more types of monomers.

Examples of the other components that are non-resin components include the same additives mentioned above as other components included in the easy-peel layer.

The oxygen barrier layer may contain only one type of other components, or may include two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily determined depending on the purpose. You can choose.

Ratio of the content (parts by mass) of polyamide having an aromatic ring to the total mass (parts by mass) of the oxygen barrier layer ([Content of polyamide having aromatic rings (parts by mass) in the oxygen barrier layer] )]/[total mass (parts by mass) of the oxygen barrier layer] x 100) is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more. Preferably, it may be, for example, 97% by mass or more, or 99% by mass or more. When the ratio is equal to or higher than the lower limit value, the oxygen barrier properties of the laminated film become higher, and the laminated film or a package manufactured using the same is subjected to various types of heating such as retort treatment. Even if the treatment is performed, whitening of the laminated film or package and a decrease in oxygen barrier properties are further suppressed.
On the other hand, the ratio is 100% by mass or less.
The above ratio is usually the ratio of the content (parts by mass) of polyamide having an aromatic ring to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an oxygen barrier layer (described later). Content of polyamide having an aromatic ring in the composition for forming a barrier layer (parts by mass) / [Total content of components that do not vaporize at room temperature (parts by mass) in the composition for forming an oxygen barrier layer] × 100), is the same as

When the above-mentioned laminated film or package is heat-treated, the effect of suppressing the decrease in oxygen barrier properties of the laminated film or package is, for example, when the amount of oxygen permeation of the laminated film after heat treatment is reduced. This can be confirmed by measuring.
The laminated film of this embodiment was subjected to retort treatment at 121°C for 30 minutes, and immediately after that, the laminated film was measured in accordance with ASTM D3985 under the conditions of 23°C and 60% RH (60% relative humidity). The oxygen permeation amount is 100 cc/m ² ·atm · day or less, for example, 60 cc/m ² ·atm · day or less, 20 cc/m ² ·atm · day or less, and 10 cc/m ² ·atm · day or less It may be either.
The lower limit of the oxygen permeation amount of the laminated film is not particularly limited. For example, a laminated film having an oxygen permeation rate of 0.1 cc/m ² ·atm ·day or more is easily available.

As used herein, "retort treatment" means moist heat sterilization at a temperature exceeding 100° C. under pressure. The term "retort food" refers to food that is intended to be retorted while being packaged in a package.

The oxygen barrier properties of the laminated film and the package, and the effect of suppressing the decrease in the oxygen barrier property of the laminated film or the package when the laminated film or the package is heat-treated, are determined by, for example, polyamide, etc. It can be adjusted by adjusting the type and content of the components contained in the oxygen barrier layer.

The oxygen barrier layer may be composed of one layer (single layer) or may be composed of two or more layers. When the oxygen barrier layer is composed of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.

The thickness of the oxygen barrier layer is preferably 15 to 80 μm, and may be, for example, 20 to 60 μm or 25 to 45 μm. When the thickness of the oxygen barrier layer is equal to or greater than the lower limit value, the oxygen barrier property of the laminated film becomes higher, and the laminated film or a package manufactured using the same can be subjected to retort treatment or other treatments. Even if various heat treatments are performed, the deterioration of the oxygen barrier properties of the laminated film or package is further suppressed. When the thickness of the oxygen barrier layer is equal to or less than the above upper limit, the flexibility of the oxygen barrier layer becomes higher. In addition, as the thickness of the oxygen barrier layer becomes thinner, the transparency of the package (for example, the bottom material described below) improves, so that stored items from the outside on the laminated film side (for example, the bottom material side) of the package improve. Visual recognition becomes easier.
Here, the "thickness of the oxygen barrier layer" means the thickness of the entire oxygen barrier layer. For example, the thickness of an oxygen barrier layer consisting of multiple layers is the total thickness of all the layers that make up the oxygen barrier layer. means the thickness of

The thickness of the oxygen barrier layer (the thickness of the laminated film shown in FIG. 1 is the thickness T ₁ in the laminated film 1 shown in FIG. 1, and the thickness T 2 is the thickness T ₂ in the laminated film 2 shown in FIG. 2) of the laminated film. In the film 1 and the laminated film 2 shown in FIG. 2, the ratio of the thickness T ₁₃ ) is 60% or less, and may be, for example, any of 50% or less, 40% or less, and 30% or less. . When the ratio is below the upper limit, the oxygen barrier layer can be prevented from becoming relatively thick, and when such a laminated film is manufactured by a method involving extrusion of a resin or resin composition. , foaming of the oxygen barrier layer and the resin or composition for forming the oxygen barrier layer is suppressed, and a laminated film can be easily produced with high quality.
The lower limit of the ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film is not particularly limited. For example, a laminated film in which the ratio is 3% or more can be manufactured more easily.
In one embodiment, the ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film is, for example, any one of 3 to 60%, 4 to 50%, 5 to 40%, and 6 to 30%. It's okay. However, these are examples of the above ratios.

<Middle layer>
The intermediate layer (intermediate layer 14 in the laminated film 1 shown in FIG. 1 and the laminated film 2 shown in FIG. 2) is arranged between the easy-peel layer and the outer layer in the laminated film.
The intermediate layer does not correspond to any of the water vapor barrier layer, the oxygen barrier layer, and the adhesive layer described below.
An example of the intermediate layer is a pinhole resistant layer for imparting pinhole resistance to the laminated film. The pinhole resistance of such an intermediate layer (pinhole resistant layer) is significantly exhibited even when the package is bent.

It is preferable that the intermediate layer has transparency.

The laminated film may include the intermediate layer between the easy-peel layer and the outer layer, but it may be provided adjacent to the oxygen barrier layer (in other words, the intermediate layer and the oxygen barrier layer are in contact with each other). ) is preferred. By arranging the intermediate layer in this way, the intermediate layer and the oxygen barrier layer are combined to form a laminated film, and the total thickness of the intermediate layer and oxygen barrier layer is determined as the oxygen barrier without the intermediate layer. As explained above, if the ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film is made smaller than that of the case without the intermediate layer by making it approximately the same as the thickness of the layer, manufacturing of the laminated film At times, foaming of the oxygen barrier layer and the resin or composition for forming the oxygen barrier layer can be suppressed, and a laminated film can be easily produced with high quality. Furthermore, by making the total thickness of the intermediate layer and the oxygen barrier layer about the same as the thickness of the intermediate layer without the oxygen barrier layer, the ratio of the thickness of the intermediate layer to the thickness of the laminated film is increased. is smaller than that without an oxygen barrier layer, the occurrence of cutting defects in the laminated film (more specifically, the intermediate layer) when cutting the manufactured laminated film into the desired size or shape. can be suppressed. Usually, when an oxygen barrier layer is not provided, the thickness of the intermediate layer needs to be thicker than when an oxygen barrier layer is provided.

The intermediate layer may include polyamide.
The intermediate layer is preferably a resin layer containing polyamide without an aromatic ring (herein sometimes referred to as "non-aromatic polyamide"). Such an intermediate layer is suitable as an anti-pinhole layer.

As the polyamide without an aromatic ring (non-aromatic polyamide), for example, a cyclic lactam (a lactam having 3 or more ring members), an amino acid, or a nylon salt obtained by a reaction between a diamine and a dicarboxylic acid, Examples include polyamides obtained by polymerization or copolymerization.

Examples of the cyclic lactam include ε-caprolactam, ω-enantholactam, ω-laurolactam, α-pyrrolidone, α-piperidone, and the like.

Examples of the amino acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

Examples of the diamine forming the nylon salt include tetramethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2, Aliphatic amines such as 4-trimethylhexamethylene diamine and 2,4,4-trimethylhexamethylene diamine;
1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, isophoronediamine, piperazine, bis(4-aminocyclohexyl)methane, 2,2-bis-(4-aminocyclohexyl)propane, etc. and alicyclic diamines.

Examples of the dicarboxylic acid that forms the nylon salt include aliphatic dicarboxylic acids such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, cepatic acid, undecanedioic acid, and dodecanedioic acid;
Examples include alicyclic carboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid.

More specifically, the polyamides include, for example, 4-nylon, 6-nylon, 7-nylon, 11-nylon, 12-nylon, 46-nylon, 66-nylon, 69-nylon, 610-nylon, and 611-nylon. Nylon, 612-nylon, 6T-nylon, 6I nylon, copolymer of 6-nylon and 66-nylon (nylon 6/66), copolymer of 6-nylon and 610-nylon, copolymer of 6-nylon and 611-nylon Copolymer, copolymer of 6-nylon and 12-nylon (nylon 6/12), copolymer of 6-nylon and 612 nylon, copolymer of 6-nylon and 6T-nylon, copolymer of 6-nylon and 6I-nylon , copolymer of 6-nylon, 66-nylon and 610-nylon, copolymer of 6-nylon, 66-nylon and 12-nylon (nylon 6/66/12), 6-nylon, 66-nylon and 612-nylon Copolymers of 66-nylon and 6T-nylon, copolymers of 66-nylon and 6I-nylon, copolymers of 6T-nylon and 6I-nylon, copolymers of 66-nylon, 6T-nylon and 6I-nylon Examples include copolymers and the like.

In terms of heat resistance, mechanical strength, and availability, the polyamides are 6-nylon (herein sometimes abbreviated as "Ny6"), 12-nylon, and 66-nylon. , nylon 6/66, nylon 6/12 or nylon 6/66/12.

The intermediate layer may contain only one kind of polyamide, or may contain two or more kinds of polyamides, and in the case of two or more kinds, the combination and ratio thereof can be arbitrarily selected depending on the purpose.

The intermediate layer may contain only polyamide (that is, may consist of polyamide), or may contain polyamide and other components (herein referred to as "other components"). (i.e., it may consist of polyamide and the other components mentioned above).

The other components contained in the intermediate layer are not particularly limited and can be arbitrarily selected depending on the purpose, and may be, for example, either a resin component or a non-resin component.
The other component, which is a resin component, is a resin that does not fall under either aromatic polyamide or non-aromatic polyamide (that is, a resin other than polyamide).
The other component, which is a resin component, may be a homopolymer that is a polymer of one type of monomer, or a copolymer that is a polymer of two or more types of monomers.

Examples of the other components that are non-resin components include the same additives mentioned above as other components included in the easy-peel layer.

The intermediate layer may contain only one type of other components, or may include two or more types, and in the case of two or more types, the combination and ratio thereof may be arbitrarily selected depending on the purpose. can.

The ratio of the polyamide content (parts by mass) to the total mass (parts by mass) of the intermediate layer in the intermediate layer ([polyamide content (parts by mass) of the intermediate layer]/[total mass (parts by mass) of the intermediate layer] ]×100) is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, for example, 97% by mass or more, and 99% by mass or more. It may be either. When the ratio is greater than or equal to the lower limit, the pinhole resistance of the laminated film becomes higher.
On the other hand, the ratio is 100% by mass or less.
The above ratio is usually the ratio of the polyamide content (parts by mass) to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an intermediate layer, which will be described later. Polyamide content (parts by mass)])/[total content of components that do not vaporize at room temperature (parts by mass) of the composition for forming an intermediate layer]×100).

The intermediate layer may be composed of one layer (single layer) or may be composed of two or more layers. When the intermediate layer is composed of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.

The thickness of the intermediate layer is preferably 15 to 80 μm, and may be, for example, 20 to 60 μm or 25 to 45 μm. When the thickness of the intermediate layer is equal to or greater than the lower limit value, the effect obtained by including the intermediate layer (for example, pinhole resistance) becomes higher. When the thickness of the intermediate layer is equal to or less than the above upper limit, poor cutting of the laminated film can be further suppressed. In addition, as the thickness of the intermediate layer becomes thinner, the transparency of the package (for example, the bottom material described below) improves, so that stored items from the outside on the laminated film side (for example, the bottom material side) of the package improve. Visual recognition becomes easier.
Here, the "thickness of the intermediate layer" means the thickness of the entire intermediate layer. For example, the thickness of an intermediate layer consisting of multiple layers refers to the total thickness of all the layers that make up the intermediate layer. means.

The ratio of the thickness of the intermediate layer to the thickness of the laminated film is preferably 50% or less. When the ratio is equal to or less than the upper limit value, poor cutting of the laminated film can be suppressed.
The ratio of the thickness of the intermediate layer to the thickness of the laminated film is more preferably 3 to 49%, even more preferably 4 to 48%, particularly preferably 5 to 47%. When the ratio of the thickness of the intermediate layer to the thickness of the laminated film is equal to or greater than the lower limit, the effect obtained by including the intermediate layer (for example, pinhole resistance) becomes higher. When the ratio of the thickness of the intermediate layer to the thickness of the laminated film is equal to or less than the upper limit value, poor cutting of the laminated film can be further suppressed.

<Adhesive layer>
The laminated film of this embodiment may include an adhesive layer that does not correspond to any of the easy peel layer, water vapor barrier layer, oxygen barrier layer, intermediate layer, and outer layer.
The adhesive layer is a layer for adhering two adjacent layers in a laminated film, and contains a component that exhibits adhesive properties.

The position of the adhesive layer in the laminated film is not particularly limited as long as it is not the outermost layer of the laminated film.
The adhesive layer may be arranged at one location or at two or more locations in the laminated film. When the adhesive layers are arranged at two or more locations in the laminated film, the adhesive layers at these two or more locations may be the same or different from each other. Here, "the adhesive layers at two or more places may be the same or different from each other" means "all the adhesive layers may be the same, all the adhesive layers may be different, or the same "Only the adhesive layers of the adhesive layers may be the same" and "the adhesive layers are different from each other" means "at least one of the constituent materials and thicknesses of the adhesive layers are different from each other".

The laminated film may include, for example, an adhesive layer (first adhesive layer 161 in the laminated film 1 shown in FIG. 1 and the laminated film 2 shown in FIG. 2) between the water vapor barrier layer and the oxygen barrier layer. However, an adhesive layer ("second adhesive layer 162" in the laminated film 1 shown in FIG. 1 and the laminated film 2 shown in FIG. 2) may be provided between the intermediate layer and the outer layer.

It is preferable that the adhesive layer has transparency.
The adhesive layer has an arbitrary structure, and the laminated film does not need to have an adhesive layer, but the structure becomes more stable by including the adhesive layer.

The adhesive layer is preferably a resin layer containing an adhesive resin.

Examples of the adhesive resin include polyolefin resins.
The polyolefin resin is a resin having a structural unit derived from an olefin, and may be, for example, a modified polyolefin such as an acid-modified polyolefin having an acidic group.
Examples of polyolefin resins include ethylene copolymers, propylene copolymers, butene copolymers, modified products of these copolymers (in other words, modified copolymers), acid-modified polyethylene, acid-modified polypropylene, etc. can be mentioned.
The polyolefin resin may be a random copolymer, a graft copolymer, or a block copolymer in terms of improved adhesiveness.

Examples of the ethylene copolymer contained in the adhesive layer include the ethylene copolymer described above as being contained in the easy peel layer, modified products thereof (modified copolymers), and the like.
Examples of the propylene copolymer contained in the adhesive layer include a copolymer of propylene and a vinyl group-containing monomer, a modified product thereof (modified copolymer), etc. Also included are the propylene copolymers described above. More specific examples of such propylene-based copolymers include maleic anhydride graft-modified linear low-density polypropylene, propylene-based thermoplastic elastomers, and the like.
Examples of the butene-based copolymers contained in the adhesive layer include copolymers of 1-butene and vinyl group-containing monomers, copolymers of 2-butene and vinyl group-containing monomers, and modified products of these copolymers. (modified copolymer), etc.

The adhesive layer may contain only one type of component that exhibits adhesiveness (for example, the adhesive resin), or may include two or more types, and if there are two or more types, a combination thereof. and the ratio can be arbitrarily selected depending on the purpose.

The adhesive layer may contain other components in addition to the component that exhibits adhesiveness (for example, the adhesive resin) within a range that does not impair its adhesiveness.
Examples of the other components contained in the adhesive layer include antioxidants and the like.

The adhesive layer may contain only one type of other components, or may include two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected depending on the purpose. can.

In the adhesive layer, the ratio of the content of the component that exhibits adhesiveness to the total mass of the adhesive layer ([Content of the component that exhibits adhesiveness in the adhesive layer (parts by mass)]/[Total mass of the adhesive layer (mass)] [parts)]×100) is preferably 80% by mass or more, more preferably 90% by mass or more. When the ratio is greater than or equal to the lower limit, the adhesiveness of the adhesive layer becomes higher.
On the other hand, the ratio is 100% by mass or less.
The above ratio is usually the ratio of the content (parts by mass) of components that exhibit adhesiveness to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an adhesive layer (described later). The content of components that exhibit adhesiveness in the forming composition (parts by mass)]/[Total content of components that do not vaporize at room temperature in the composition for forming an adhesive layer (parts by mass)] x 100) be.

The adhesive layer per location may be composed of one layer (single layer) or may be composed of two or more layers. When the adhesive layer consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.

The thickness of the adhesive layer per point is not particularly limited, but is preferably 0.1 to 25 μm, and may be, for example, either 1 to 20 μm or 2 to 15 μm. When the thickness of the adhesive layer is greater than or equal to the lower limit, the adhesive layer has better adhesive properties. By setting the thickness of the adhesive layer to be less than or equal to the upper limit value, it is possible to prevent the adhesive layer from becoming excessively thick. In addition, as the thickness of the adhesive layer becomes thinner, the transparency of the package (for example, the bottom material, which will be described later) improves. Visual recognition becomes easier.
Here, the "thickness of the adhesive layer" means the thickness of the entire adhesive layer. For example, the thickness of an adhesive layer consisting of multiple layers refers to the total thickness of all the layers that make up the adhesive layer. means.

<Other layers>
The type, number and position of the other layers are not particularly limited and can be arbitrarily selected depending on the purpose.
For example, the laminated film may include only one type of other layer, or may include two or more types, and when there are two or more types, the combination and ratio of them may be determined depending on the purpose. can be selected arbitrarily.

Each of the other layers may be composed of one layer (single layer) or may be composed of two or more layers. When the other layer is composed of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.

The thickness of the other layer can be arbitrarily set depending on the type thereof, and is not particularly limited.

When the laminated film includes the other layer, the adhesive layer for adhering the other layer to other layers (for example, the first adhesive layer 161 or the second adhesive layer in the laminated film 1 shown in FIG. It may further include a layer similar to the adhesive layer 162, etc.).

The laminated film of the present embodiment is suitable for constructing various packages, and is particularly suitable as a bottom material for packages to be subjected to various heat treatments including retort treatment. It is further suitable as a bottom material in a vacuum packaging body for performing heat treatment (a packaging body for performing the heat treatment after vacuum packaging). Examples of the object to be packaged in this case include foodstuffs and the like.
That is, the laminated film of this embodiment is more suitable for packaging retort foods, and even more suitable for vacuum packaging retort foods.

The thickness of the laminated film is not particularly limited, but is preferably 100 to 320 μm, and may be, for example, either 100 to 280 μm or 100 to 240 μm. Since the thickness of the laminated film is equal to or greater than the lower limit value, the storage stability of the packaged object is higher in the package obtained using the laminated film, and the structure of the package is stably maintained. characteristics become higher. When the thickness of the laminated film is equal to or less than the above upper limit, the moldability of the laminated film becomes higher. In addition, as the thickness of the laminated film becomes thinner, the transparency of the package (bottom material described below) improves, making it easier to visually recognize the stored items from the outside on the bottom material side of the package.

<Characteristics of laminated film>
It is preferable that all the layers included in the laminated film have transparency, and that the laminated film has transparency, that is, the laminated film is a transparent laminated film. In a package obtained using such a laminated film, the packaged object can be easily recognized through the laminated film.

[Haze]
The haze of the laminated film is not particularly limited. For example, the haze of the laminated film may be 25% or less, preferably 20% or less, and more preferably 16% or less. The lower the haze of the laminated film, the better the transparency of the package (e.g., the bottom material described below), which makes it easier to see the stored items from the outside on the laminated film side of the package (e.g., the bottom material side). It becomes easier.

In this specification, "haze of a laminated film" means a measured value obtained by measuring a laminated film from the outside on its outer layer side in accordance with JIS K 7136:2000, unless otherwise specified. do.

The haze of the laminated film can be adjusted by, for example, adjusting the type and content of components contained in each layer constituting the laminated film, the thickness of each layer, and the like.

<<Manufacturing method of laminated film>>
The laminated film of this embodiment can be produced by, for example, a feed block method in which resins or resin compositions, etc. that are forming materials for each layer are melt-extruded using several extruders, or a coextrusion T-die method such as a multi-manifold method. , air-cooled or water-cooled coextrusion inflation method, etc.

In addition, the laminated film of this embodiment can be coated with a resin or a resin composition, etc., which is a forming material for any of the layers, on the surface of another layer to constitute the laminated film, as necessary. It can also be manufactured by drying to form a laminated structure in a laminated film, and if necessary, further laminating layers other than these to form the desired arrangement.

In addition, in the laminated film of this embodiment, two or more films for configuring any two or more of the layers are prepared separately in advance, and these films are glued together using a dry lamination method or extrusion method. It can also be manufactured by bonding and stacking layers by any one of a laminating method, a hot melt laminating method, and a wet laminating method, and, if necessary, further layering other layers so as to form the desired arrangement. At this time, an adhesive capable of forming the adhesive layer (first adhesive layer, second adhesive layer) may be used as the adhesive.

Furthermore, as described above, the laminated film of this embodiment is obtained by laminating two or more films that have been produced separately in advance and pasting them together using a thermal lamination method or the like without using an adhesive. , If necessary, it can also be manufactured by further laminating layers other than these to obtain the desired arrangement.

When manufacturing the laminated film of this embodiment, two or more of the methods for forming any of the layers (films) in the laminated film listed above may be combined.

Regardless of the manufacturing method, the resin composition that serves as the forming material for any layer in the laminated film contains the intended components (constituent materials) of the layer to be formed, in an intended content. The type and content of the ingredients may be adjusted so that the amount of the product is contained in the product. For example, the content ratio of components that do not vaporize at room temperature in the resin composition is usually the same as the content ratio of the components in a layer formed from this resin composition.

Of the easy peel layer (the easy peel layer 11 in the laminated film 1 shown in FIG. 1 and the laminated film 1 shown in FIG. 2), the resin composition for forming the easy peel layer of the above-mentioned first embodiment (the present invention) is In the specification, the composition (sometimes referred to as the "first easy-peel layer forming composition") includes, for example, the above-mentioned propylene-based polymer having a melting point of 130° C. or higher, and optionally an anti-blocking agent, Furthermore, if necessary, there may be mentioned a resin composition containing either or both of the ethylene polymer and other components.

Among the easy-peel layers, the resin composition for forming the easy-peel layer of the above-mentioned second embodiment (herein sometimes referred to as "second easy-peel layer forming composition") is For example, a resin composition containing the above-mentioned propylene-based polymer having a melting point of 130° C. or higher, an anti-blocking agent, and, if necessary, one or both of the above-mentioned propylene-based polymer and other components. Can be mentioned.

The method for producing the composition for forming an easy-peel layer is not particularly limited, but includes a method of adding an anti-blocking agent to the resin contained in the easy-peel layer and kneading the resin. From the viewpoint of improving dispersion efficiency, a dispersant, a coupling agent, etc. may be added during kneading.

A resin composition for forming an outer layer (outer layer 15 in the laminated film 1 shown in FIG. 1 and the laminated film 1 shown in FIG. 2) (herein sometimes referred to as "outer layer forming composition") ) may include, for example, a resin composition containing the propylene-based polymer having a melting point of 130° C. or higher and, if necessary, the other components.

A resin composition for forming an intermediate layer (in the laminated film 1 shown in FIG. 1 and the intermediate layer 14 in the laminated film 1 shown in FIG. 2) (herein referred to as "composition for forming an intermediate layer"). For example, a resin composition containing a polyamide having no aromatic ring and, if necessary, the other components described above can be mentioned.

A resin composition for forming an oxygen barrier layer (the oxygen barrier layer 13 in the laminated film 1 shown in FIG. 1 and the laminated film 1 shown in FIG. 2) (herein referred to as "composition for forming an oxygen barrier layer"). Examples of the resin composition include a polyamide having an aromatic ring and, if necessary, the other components described above.

A resin composition for forming a water vapor barrier layer (water vapor barrier layer 12 in the laminated film 1 shown in FIG. 1 and the laminated film 1 shown in FIG. 2) (herein referred to as "composition for forming a water vapor barrier layer"). Examples of the resin composition include the above-mentioned propylene-based polymer having a melting point of 130° C. or higher and, if necessary, the other components.

A resin composition (herein referred to as "adhesive") for forming an adhesive layer (the first adhesive layer 161 or the second adhesive layer 162 in the laminated film 1 shown in FIG. Examples of the layer-forming composition (sometimes referred to as "layer-forming composition") include resin compositions containing the above-mentioned component that exhibits adhesiveness and, if necessary, the other components.

＜＜Package＞＞
A package according to one embodiment of the present invention includes the above-described laminated film according to one embodiment of the present invention.
Since the packaging body of this embodiment is constructed using the laminated film, even if heat treatment is performed, whitening and deterioration of oxygen barrier properties are suppressed, and it is heat resistant and free from food-generated substances. Equipped with an easy-peel layer that prevents liquid from adhering.

The food to be packaged in the package of this embodiment is not particularly limited. Examples of the foods include known foods such as fresh foods such as raw meat, raw fish, and raw vegetables; various processed foods including processed meat products such as ham, sausages, and bacon.

The package preferably includes, for example, a lid material and a bottom material, and is configured by sealing the lid material and the bottom material, and either or both of the lid material and the bottom material Examples include packaging bodies made of laminated films.
Among these, since the advantageous effects of using the laminated film are particularly noticeable, the package includes a lid material and a bottom material, and is configured by sealing the lid material and the bottom material. Preferably, the bottom material is a package made of the laminated film. In such a package, the lid material may be made of the laminated film. The laminated film is suitable for molding, and when the intermediate layer is a pinhole-resistant layer, the laminated film has high pinhole resistance when bent, so such a laminated film is used. By doing so, it is possible to more easily manufacture a package having a bottom material having a desired shape.

When the bottom material is made of the laminated film, the bottom material may be a deep drawn product.

FIG. 3 is a cross-sectional view schematically showing an example of the package of this embodiment.
The package 10 shown here includes a bottom material 1' and a lid material 8.
The bottom material 1' is a molded body of the laminated film 1 shown in FIG. 1 or 2. In FIG. 3, the distinction between each layer in the laminated film 1 constituting the bottom material 1' is omitted.

The lid material 8 may be made of the laminated film according to the embodiment of the present invention, such as the laminated film 1, or may be any other known lid material.
As the well-known lid material 8, for example, a lid material made of a single-layer or multilayer resin film can be mentioned.

It is preferable that the package 10 is a vacuum package.

One surface 8a (sometimes referred to as "first surface" in this specification) of the lid material 8 is a sealing surface, and includes a part of the first surface 8a and the bottom material 1' (laminated film). 1) A part of the second surface 11b of the easy-peel layer 11 inside is in close contact with the second surface 11b by a seal. In FIG. 3, the portion where the first surface 8a of the lid material 8 and the second surface 11b of the easy-peel layer 11 in the bottom material 1' (laminated film 1) are in direct contact is the seal portion. The space between the first surface 8a of the lid member 8 and the second surface 11b of the sealant layer 11 serves as the storage portion 10a. An object to be packaged (in other words, an object to be packaged or an object to be packaged) 9 is stored in this storage section 10a.

In FIG. 3, there are some gaps between the packaged object 9 and the bottom material 1' and between the packaged object 9 and the lid material 8 in the storage section 10a of the package 10. However, these gaps may not exist in the package 10 in which the packaged object 9 is stored.

In the package 10, the thickness of the flat portion of the bottom material 1' is the same as the thickness of the laminated film described above.

In the package 10, the thickness of the lid member 8 is not particularly limited, but is preferably 40 to 400 μm, and may be, for example, either 50 to 300 μm or 60 to 200 μm. The strength of the lid material 8 is further improved because the thickness of the lid material 8 is greater than or equal to the lower limit value. Since the thickness of the lid material 8 is equal to or less than the upper limit value, the thickness of the lid material 8 is prevented from becoming excessive.
Here, the "thickness of the lid material 8" means the thickness of the entire lid material 8. For example, the thickness of the lid material 8 consisting of multiple layers refers to the total thickness of all the layers constituting the lid material 8. means the thickness of

The object to be packaged 9 can be arbitrarily selected depending on the purpose, and is not particularly limited, and examples thereof include the food and the like described above as the "object to be packaged."

The package of this embodiment is not limited to the package 10 shown in FIG. 3, and some of the configurations may be changed, deleted, or added to the package 10 shown in FIG. 3 without departing from the spirit of the present invention. It may also be a packaged product.
For example, FIG. 3 shows a package 10 in which the bottom material is constructed using the laminated film 1 shown in FIG. 1 or FIG. 2, but in the package of this embodiment, the bottom material is It may be configured using the above-mentioned laminated film other than the laminated film 1.

<Heat resistance of the outer layer in the package (laminated film)>
For example, a plurality of packages are heat-treated at 95 to 105°C for 20 to 40 minutes with the outer layers of the laminated films in these packages in contact with each other, and the outer layers in these heat-treated packages are By checking the presence or absence of fusion, the heat resistance of the outer layer in the package (laminated film) can be evaluated.

<Heat resistance of the easy peel layer in the package (laminated film)>
For example, by heat-treating the package at 95-105°C for 20-40 minutes and checking whether the easy-peel layer in the laminated film is fused in the heat-treated package, the package (laminated film ) can evaluate the heat resistance of the easy peel layer inside.
Furthermore, the heat resistance of the easy-peel layer in the package (laminated film) can also be evaluated based on the peel strength of the sealed portion of the heat-treated package.
In addition, when the heat-treated package is dropped in accordance with JIS Z 0202 Level 1, the seal portion (between the bottom material and the lid material) in the package may peel off (seal dropout). The heat resistance of the easy-peel layer in the package (laminated film) can also be evaluated by checking the presence or absence of .

[Peel strength of seal portion at 100°C]
When the temperature of the package of this embodiment was adjusted to 100°C and the peel strength (N/15 mm) of the seal portion of the package in this state was measured in accordance with JIS Z 0238:1998, the peel strength was For example, it may be 1.4N/15mm or more, but preferably 2.2N/15mm or more, and even if it is any of 3N/15mm or more, 4N/15mm or more, and 5N/15mm or more. good. A package whose peel strength is equal to or higher than the lower limit when the temperature of the package is adjusted to 100°C has a higher heat resistance (more specifically, the heat resistance of the easy peel layer in the laminated film). expensive.
On the other hand, for example, a package whose peel strength is 8 N/15 mm or less when the temperature of the package is adjusted to 100° C. can be opened more easily during use.
The peel strength when the temperature of the package is adjusted to 100°C is, for example, a 50 μm thick sealant layer containing linear low density polyethylene (LLDPE), preferably a 50 μm thick sealant layer comprising linear low density polyethylene. By heat-sealing the sealant layer in the resin film comprising the sealant layer and the easy-peel layer in the laminated film under conditions of a sealing temperature of 150 ° C., a sealing time of 2 seconds, and a sealing pressure of 0.5 MPa. It may also be the peel strength of the resulting package.

<<Method for manufacturing the package>>
The package of this embodiment can be manufactured by packaging the object to be packaged using the laminated film. The package of this embodiment can be manufactured by the same method as the conventional package, except that the laminated film is used instead of the conventional film.

For example, a vacuum packaged body including a bottom material obtained using the laminated film and a lid material may be manufactured by molding the laminated film to provide a bottom material with a recess for forming the storage section. The object to be packaged is placed on the second surface of the easy-peel layer in the bottom material (in other words, the surface that is sealed with the lid material), and the surface of the bottom material and The lid material is placed over the object to be packaged from above, and a region between the bottom material and the lid material where the object to be packaged is placed is evacuated, and the object to be packaged is placed. It can be manufactured by heat-sealing the bottom material and the lid material in the area where the bottom material and the lid material are not sealed.

It is preferable that the pressure in the region where the object to be packaged is placed is 5000 Pa (50 mbar) or less due to evacuation during heat sealing. When the pressure is equal to or lower than the upper limit value, a package can be obtained that has higher storage suitability for the packaged object (in other words, the stored object or the packaged object).

The sealing temperature during heat sealing is not particularly limited, but is preferably 100 to 170°C. When the sealing temperature is equal to or higher than the lower limit, for example, the sealing strength of the package becomes higher while having easy peelability. When the sealing temperature is below the upper limit value, the package can be opened more easily.

The sealing time during heat sealing can be adjusted as appropriate depending on the sealing temperature, but is usually preferably 1 to 30 seconds. When the sealing time is equal to or greater than the lower limit, the sealing strength of the package becomes higher while having easy peelability. When the sealing time is equal to or less than the upper limit, the package can be opened more easily.

The sealing pressure during heat sealing can be adjusted as appropriate depending on the sealing temperature, but is usually preferably 0.1 to 1 MPa. When the sealing pressure is equal to or higher than the lower limit value, the sealing strength of the package becomes higher while having easy peelability. When the sealing pressure is equal to or lower than the upper limit value, the package can be opened more easily.

Hereinafter, the present invention will be explained in more detail with reference to specific examples. However, the present invention is not limited to the examples shown below.

The resins used in each example or comparative example are as follows.
rPP (1): Polypropylene random copolymer (“S131” manufactured by Sumitomo Chemical Co., Ltd., melting point 132°C)
rPP (2): Polypropylene random copolymer (“FL8115A” manufactured by Sumitomo Chemical Co., Ltd., melting point 148°C)
rPP (3): Polypropylene random copolymer (“FL331G5” manufactured by Sumitomo Chemical Co., Ltd., melting point 138°C)
rPP (4): Polypropylene random copolymer (“WFX4TA” manufactured by Nippon Polypro Co., Ltd., melting point 125°C)
hPP: Homopolypropylene (“WF836DG3” manufactured by Sumitomo Chemical Co., Ltd., melting point 158°C)
hmsPP: Metallocene-based high melt tension polypropylene (MFX3 manufactured by Nippon Polypropylene, melting point 160°C, melt tension at 230°C 5.0 g)
Acid-modified PP: Acid-modified polypropylene (adhesive resin, "QF551" manufactured by Mitsui Chemicals)
Ny6:6-nylon (non-aromatic polyamide, “1030B2” manufactured by Ube Industries)
MXNy: Poly(methaxylylene adipamide) (aromatic polyamide, "S6011" manufactured by Mitsubishi Gas Chemical Co., Ltd.)
LDPE (1): Low density polyethylene (“F522N” manufactured by Ube Maruzen Polyethylene Co., Ltd., melting point 110°C, density 0.922g/cm ³ )
LDPE (2): Low density polyethylene (“F234” manufactured by Ube Maruzen Polyethylene Co., Ltd., melting point 118°C, density 0.938g/cm ³ )
HDPE: High-density polyethylene (“3300F” manufactured by Prime Polymer, melting point 130°C, density 0.949g/cm ³ )

[Example 1]
<<Manufacture of laminated film>>
A laminated film having the configuration shown in FIG. 1 was manufactured by the procedure shown below.
That is, the LDPE (1) and the rPP (1) are prepared as resins constituting the easy peel layer, the hPP and hmsPP are prepared as resins constituting the water vapor barrier layer, and the oxygen barrier layer is constituted. The MXNy is prepared as a resin, the Ny6 is prepared as a resin constituting the intermediate layer, the rPP (2) is prepared as a resin constituting the outer layer, and the first adhesive layer and the second adhesive layer are constituted. The acid-modified PP was prepared as an adhesive resin.

By mixing the LDPE (1) (30 parts by mass), the rPP (1) (70 parts by mass), and the AB (0.2 parts by mass) at room temperature, an easy-peel layer forming composition (1) is prepared. was manufactured.
A water vapor barrier layer forming composition (1) was produced by mixing the hPP (70 parts by mass) and the hmsPP (30 parts by mass) at room temperature.

The temperature of the die was set to 250°C, and the composition for forming an easy peel layer (1), the composition for forming a water vapor barrier layer (1), the acid-modified PP, the MXNy, the Ny6, and the acid By coextruding the modified PP and the rPP (2) in this order (coextrusion T-die method), an easy peel layer (thickness 11 μm), a water vapor barrier layer (thickness 28 μm), and a first adhesive layer are formed. (thickness 18 μm), oxygen barrier layer (thickness 22 μm), intermediate layer (thickness 40 μm), second adhesive layer (thickness 16 μm), and outer layer (thickness 45 μm) are laminated in this order in the thickness direction. A laminated film (thickness: 180 μm) was obtained.

<<Evaluation of laminated film>>
<Measurement of surface roughness Rsm of the sealing surface of the easy peel layer of the laminated film>
Regarding the laminated film obtained above, the surface roughness Rsm (μm) of the sealing surface of the easy peel layer was measured in accordance with JIS B 0601. The results are shown in Table 1.

<Measurement of melt tension of water vapor barrier layer>
A single-layer water vapor barrier layer (thickness: 28 μm), which was the same as that in the laminated film, was produced by extrusion molding, and this was used as a test piece. The melt tension (g) of this test piece was measured using a capillograph in accordance with JIS K7199:1999. The results are shown in Table 1.

<Evaluation of the foaming suppression effect in the oxygen barrier layer of the laminated film>
The laminated film obtained above was visually observed to confirm the presence or absence of foaming in the oxygen barrier layer. Then, the effect of suppressing foaming in the oxygen barrier layer was evaluated according to the following criteria. The results are shown in the column of "Oxygen barrier layer foaming suppression effect" in Table 1.
(Evaluation criteria)
A: No foaming was observed in the oxygen barrier layer, and foaming of the oxygen barrier layer and the resin for forming it was suppressed during the production of the laminated film.
B: Foaming was observed in the oxygen barrier layer, and foaming of the oxygen barrier layer or the resin for forming it was not suppressed during production of the laminated film.

<Measurement of haze of laminated film>
Regarding the laminated film obtained above, the haze (%) was measured from the outside of the outer layer side in accordance with JIS K 7136:2000. The results are shown in Table 1.

In Table 1, the description "LDPE (1)/rPP (1) (30/70)" in the "Material (mass%)" column of "Easy Peel Layer" means "Easy Peel Layer" in this example. This means that the content ratio of LDPE (1) in the layer is 30% by mass and the content ratio of rPP (1) is 70% by mass with respect to the total mass of the easy-peel layer. The same applies to other layers, and in this example, the description "hPP/hmsPP (70/30)" in the "Material (mass%)" column of "Water vapor barrier layer" This means that the content ratio of hPP is 70% by mass and the ratio of hmsPP content is 30% by mass with respect to the total mass of the water vapor barrier layer.

<Measurement of oxygen permeation amount of laminated film after retort treatment>
The laminated film obtained above was subjected to retort treatment at 121°C for 30 minutes, and immediately thereafter, the retorted laminated film was subjected to retort treatment at a temperature of 23°C and a relative humidity of 60% in accordance with ASTM D3985. The amount of oxygen permeation was measured. The results are shown in Table 1.

<Evaluation of the effect of suppressing winding misalignment after transporting the original fabric>
Regarding the laminated film obtained above, a 422 mm original film was wound up with a tension of 100 N/m. Thereafter, the presence or absence of winding misalignment when the original fabric was transported 600 km was confirmed, and the effect of suppressing winding misalignment after transporting the original fabric was evaluated according to the following criteria. The results are shown in Table 1.
(Evaluation criteria)
A: No winding misalignment occurred after transporting the original fabric, and the effect of suppressing winding misalignment after transporting the original fabric was observed.
B: A slight or obvious winding misalignment occurred after transporting the original fabric, and no effect of suppressing winding misalignment after transporting the original fabric was observed.

<<Manufacture of packaging>>
<Manufacture of lid material>
"Takelac (registered trademark) A520" manufactured by Mitsui Chemicals, Inc. was prepared as a main agent, and "Takenate (registered trademark) A10" manufactured by Mitsui Chemicals, Inc. was prepared as a curing agent.
A composition for forming an adhesive layer for a lid material was obtained by mixing the base agent (6 parts by mass), the curing agent (1 part by mass), and ethyl acetate (6 parts by mass).
An unstretched polypropylene film (FAK manufactured by Futamura Co., Ltd., thickness 30 μm) was prepared as the resin film to serve as the surface layer and sealant layer, and barrier nylon (manufactured by Unitika Co., Ltd.) was prepared as the resin film to serve as the oxygen barrier layer for the lid material. "HGB", thickness 15 μm) was prepared.
The composition for forming an adhesive layer for a lid material obtained above was applied to one side of the non-stretched polypropylene film and dried to form an adhesive layer (thickness: 2 μm). Two such laminates of the unstretched polypropylene film and the adhesive layer were produced.
Next, one surface of the barrier nylon was bonded to the exposed surface (the surface opposite to the non-stretched polypropylene film side) of the adhesive layer in one of the laminates. Furthermore, the exposed surface of the adhesive layer in the other laminate (the surface opposite to the non-stretched polypropylene film side) was bonded to the other surface of this barrier nylon.

As described above, the sealant layer (30 μm thick) made of the unstretched polypropylene film, the adhesive layer (2 μm thick), the oxygen barrier layer (15 μm thick) made of the barrier nylon, and the adhesive layer (2 μm thick) and a surface layer (thickness: 30 μm) made of the unstretched polypropylene film were laminated in this order in the thickness direction to produce a lid material for a package.

<Measurement of oxygen permeation amount of lid material>
Regarding the lid material obtained above, the oxygen permeation amount was measured under the conditions of a temperature of 23 ° C. and a relative humidity of 60% in accordance with ASTM D3985, and it was found to be 3 cc/(m ² · day · atm). .

<Manufacture of bottom material>
Using a deep drawing machine ("R-535" manufactured by Multivac), the laminated film obtained above was deep drawn at a heating temperature of 95°C, a heating time of 2.0 seconds, and a forming time of 2.5 seconds. A bottom material for a package was produced by drawing and forming a recess.

<Manufacture of packaging>
A processed meat product (200 g of hamburger steak) is placed in the recess of the bottom material obtained above, and the sealant layer of the lid material and the easy peel layer of the bottom material (laminated film) are made to face each other, and the lid The processed meat product was sandwiched between the lid material and the bottom material, and the inside of the storage section formed by the lid material and the bottom material was vacuum degassed at a temperature of 150° C. for 2 seconds. Next, the package (vacuum package, deep-draw package) is sealed by heat-sealing the peripheral edges of the lid material and bottom material under the conditions of a sealing temperature of 150° C., a sealing time of 2 seconds, and a sealing pressure of 0.5 MPa. Manufactured. Finally, the pressure in the storage section (inside the recess) was set to 1000 Pa.

<<Evaluation of packaging>>
<Evaluation of shape stability of bottom material>
Ten panelists visually observed the corner portions forming the recesses of the bottom material obtained above before manufacturing the package. Then, the shape stability of the bottom material was evaluated according to the following criteria. The results are shown in Table 1.
(Evaluation criteria)
A: All 10 panelists judged that all corners were stable and in the desired shape, indicating that the shape stability of the bottom material was high.
B: One or more panelists determined that at least some corner portions did not have the desired shape, and the shape stability of the bottom material was insufficient.

<Evaluation of cuttability of bottom material (laminated film)>
Separately, 20 packs of bottom material (laminated film) were continuously manufactured using the above method, and during this time, it was confirmed whether or not the bottom material had any cutting defects. Then, the cuttability of the bottom material was evaluated according to the following criteria. The results are shown in Table 1.
(Evaluation criteria)
A: No defective cutting of the bottom material occurred in all 20 packs, and the cutting performance of the bottom material was good.
B: Poor cutting of the bottom material occurred in at least one pack, and the cutting performance of the bottom material was insufficient.

<Evaluation of the effect of suppressing content deposition on the package after retort processing>
The package obtained above was retorted at 121°C for 30 minutes, and 10 panelists applied the contents to the sealing surface of the easy-peel layer of the bottom material (laminated film) in the retort-treated package. Visual observation was made to see if the sauce had settled. Then, the effect of suppressing content deposition on the package after retort treatment was evaluated according to the following criteria. The results are shown in Table 1.
(Evaluation criteria)
A: All 10 panelists judged that no content sag was deposited on the sealing surface of the easy-peel layer, and the effect of suppressing content deposition on the package was high.
B: One or more panelists determined that the content was deposited on the sealing surface of the easy-peel layer, and the effect of suppressing content deposition on the package was insufficient.

<Evaluation of the effect of suppressing roughness on the surface of the outer layer of the bottom material (laminated film) after retort treatment>
The package obtained above was retorted at 121° C. for 30 minutes, and 10 panelists visually observed the surface of the outer layer of the bottom material (laminated film) in the package after the retort treatment. Then, the effect of suppressing roughness on the surface of the outer layer of the bottom material was evaluated according to the following criteria. The results are shown in Table 1.
(Evaluation criteria)
A: All 10 panelists judged that no roughness was observed on the surface of the outer layer of the bottom material, and the effect of suppressing roughness on the surface of the outer layer was high.
B: One or more panelists determined that roughness was observed on the surface of the outer layer of the bottom material, and the effect of suppressing roughness on the surface of the outer layer was insufficient.

<Evaluation of easy peelability of packaging after retort processing>
Separately, the package obtained above was retorted at 121° C. for 30 minutes, and 10 panelists each attempted to open the package after the retort treatment. Then, the easy peelability of the package after retort treatment was evaluated according to the following criteria. The results are shown in Table 1.
(Evaluation criteria)
A: All 10 panelists could easily open the package, and the package had high easy-peel properties after retort treatment.
B: One or more panelists could not easily open the package, and the package had insufficient easy peelability after retort treatment.

<Evaluation of uniformity of appearance of bottom material (laminated film) after retort treatment>
When evaluating the above-mentioned "effect of suppressing roughness of the outer layer surface of the bottom material (laminated film) after retort treatment", 10 panelists visually observed the bottom material (laminated film) at the same time. Then, the uniformity of the appearance of the bottom material was evaluated according to the following criteria. The results are shown in Table 1.
A: All 10 panelists judged that the appearance of the bottom material was uniform and highly uniform, and the appearance of the bottom material was highly uniform.
B: One or more panelists determined that the appearance of the bottom material was uneven and non-uniform, and the uniformity of the appearance of the bottom material was insufficient.

<Evaluation of whitening suppression effect of bottom material (laminated film) after retort treatment>
Separately, the package obtained above was retorted at 121° C. for 30 minutes, and 10 panelists visually observed the bottom material (laminated film) in the package after the retort treatment. Then, the whitening suppressing effect of the bottom material was evaluated according to the following criteria. The results are shown in Table 1.
(Evaluation criteria)
A: All 10 panelists judged that the bottom material was not whitened at all, and the effect of suppressing whitening of the bottom material was high.
B: One or more panelists determined that the bottom material was slightly whitened, and the effect of suppressing whitening of the bottom material was recognized, but it was inferior to the case of A.
C: One or more panelists determined that the bottom material was severely whitened, and the whitening suppressing effect of the bottom material was insufficient.

<Evaluation of storage stability of packaged food after retort processing>
The package after evaluating the whitening suppressing effect of the bottom material was stored at 10° C. for 30 days. Then, 10 panelists visually observed the processed meat product in the package after storage, and evaluated the storage stability of the food in the package after retort treatment according to the following criteria. The results are shown in Table 1.
(Evaluation criteria)
A: All 10 panelists judged that there was no discoloration at all in the processed meat product, and the food in the packaged product after retort processing had high storage stability.
B: One or more panelists determined that slight discoloration was observed in the processed meat product, and the storage stability of the packaged food after retort processing was observed, but it was inferior to case A.
C: One or more panelists determined that severe discoloration was observed in the processed meat product, and the storage stability of the packaged food product after retort processing was insufficient.

<Evaluation of package openability>
Separately, 10 panelists opened the packages obtained above, and checked the feeling of peeling of the bottom material from the lid material (presence or absence of appropriate peel strength). Then, the unsealability of the package was evaluated according to the following criteria. The results are shown in Table 1.
(Evaluation criteria)
A: All 10 panelists judged that the peeling feeling was good, and the package was easy to open.
B1: One or more panelists judged that the feeling of peeling was somewhat light, and the opening property of the package was good, but it was inferior to case A.
B2: One or more panelists judged that the peeling feeling was a little heavy, and the opening property of the package was good, but it was inferior to the case of A.
C1: One or more panelists judged that the feeling of peeling was light, and the unsealability of the package was poor.
C2: One or more panelists judged that the feeling of peeling was heavy, and the opening property of the package was poor.

<Measurement of peel strength of package>
Separately, the temperature of the package obtained above was adjusted to 25° C., and the peel strength (N/15 mm) of the sealed portion of the package in this state was measured in accordance with JIS Z 0238:1998. The results are shown in Table 1.

<<Manufacture and evaluation of laminated films, and manufacture and evaluation of packages>>
[Example 2]
By mixing the LDPE (1) (30 parts by mass), the rPP (1) (70 parts by mass), and the AB (0.1 parts by mass) at room temperature, an easy-peel layer forming composition (2) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (2) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 1.

[Example 3]
By mixing the LDPE (1) (30 parts by mass), the rPP (1) (70 parts by mass), and the AB (0.5 parts by mass) at room temperature, an easy-peel layer forming composition (3) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (3) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 1.

[Example 4]
By mixing the LDPE (1) (30 parts by mass), the rPP (1) (70 parts by mass), and the AB (1.0 parts by mass) at room temperature, an easy-peel layer forming composition (4) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (4) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 1.

[Example 5]
By mixing the LDPE (1) (30 parts by mass), the rPP (1) (70 parts by mass), and the AB (1.5 parts by mass) at room temperature, an easy-peel layer forming composition (5) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (5) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 1.

[Example 6]
By mixing the LDPE (1) (30 parts by mass), the rPP (1) (70 parts by mass), and the AB (2.0 parts by mass) at room temperature, an easy-peel layer forming composition (6) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (6) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 1.

[Example 7]
By mixing the LDPE (1) (30 parts by mass), the rPP (1) (70 parts by mass), and the AB (2.5 parts by mass) at room temperature, an easy-peel layer forming composition (7) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (7) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 1.

[Example 8]
By mixing the LDPE (1) (30 parts by mass), the rPP (1) (70 parts by mass), and the AB (3.0 parts by mass) at room temperature, an easy-peel layer forming composition (8) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (8) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 1.

[Examples 9 to 12]
An easy peel layer, a water vapor barrier layer, a first adhesive layer, an oxygen barrier layer, an intermediate layer, a second adhesive layer, and an outer layer were prepared in the same manner as in Example 1, except that the conditions during coextrusion of the resin were changed. were laminated in this order in the thickness direction, and the thickness of each layer was as shown in Table 3. A laminated film (thickness: 180 μm) was produced, and this laminated film was evaluated.
A package was manufactured and evaluated in the same manner as in Example 1, except that this laminated film was used. The results are shown in Table 3.

[Example 13]
The easy peel layer, the water vapor barrier layer, the first adhesive layer, and the oxygen A laminated film (thickness 180 μm) consisting of a barrier layer, an intermediate layer, a second adhesive layer, and an outer layer laminated in this order in the thickness direction, and the thickness of each layer is the same as in Example 1. was manufactured and this laminated film was evaluated.
A package was manufactured and evaluated in the same manner as in Example 1, except that this laminated film was used. The results are shown in Table 4.

[Example 14]
The easy peel layer, the water vapor barrier layer, the first adhesive layer, and the oxygen A laminated film (thickness 180 μm) consisting of a barrier layer, an intermediate layer, a second adhesive layer, and an outer layer laminated in this order in the thickness direction, and the thickness of each layer is the same as in Example 1. was manufactured and this laminated film was evaluated.
A package was manufactured and evaluated in the same manner as in Example 1, except that this laminated film was used. The results are shown in Table 4.

[Example 15]
By mixing the LDPE (1) (34 parts by mass), the rPP (1) (66 parts by mass), and the AB (0.2 parts by mass) at room temperature, an easy-peel layer forming composition (9) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (9) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 4.

[Example 16]
By mixing the LDPE (1) (38 parts by mass), the rPP (1) (62 parts by mass), and the AB (0.2 parts by mass) at room temperature, an easy-peel layer forming composition (10) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (10) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 4.

[Example 17]
By mixing the LDPE (1) (42 parts by mass), the rPP (1) (58 parts by mass), and the AB (0.2 parts by mass) at room temperature, an easy-peel layer forming composition (11) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (11) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 5.

[Example 18]
By mixing the LDPE (1) (26 parts by mass), the rPP (1) (74 parts by mass), and the AB (0.2 parts by mass) at room temperature, an easy-peel layer forming composition (12) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (12) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 5.

[Example 19]
By mixing the LDPE (1) (22 parts by mass), the rPP (1) (78 parts by mass), and the AB (0.2 parts by mass) at room temperature, an easy-peel layer forming composition (13) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (13) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 5.

[Example 20]
By mixing the LDPE (1) (18 parts by mass), the rPP (1) (82 parts by mass), and the AB (0.2 parts by mass) at room temperature, an easy-peel layer forming composition (14) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (14) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 5.

[Example 21]
By mixing the LDPE (2) (30 parts by mass), the rPP (1) (70 parts by mass), and the AB (0.2 parts by mass) at room temperature, an easy-peel layer forming composition (15) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (15) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 6.

[Example 22]
An easy-peel layer forming composition (16) was produced by mixing the HDPE (30 parts by mass), the rPP (1) (70 parts by mass), and the AB (0.2 parts by mass) at room temperature. .
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (16) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 6.

[Example 23]
Easy peel layer, water vapor barrier layer, first adhesive layer, oxygen barrier layer, A laminated film (thickness 180 μm) was produced in which the intermediate layer, the second adhesive layer, and the outer layer were laminated in this order in the thickness direction, and the thickness of each layer was the same as in Example 1. , this laminated film was evaluated.
A package was manufactured and evaluated in the same manner as in Example 1, except that this laminated film was used. The results are shown in Table 6.

[Example 24]
An easy peel layer, a water vapor barrier layer, a first adhesive layer, an oxygen barrier layer, an intermediate layer, A laminated film (thickness: 180 μm) was produced in which the second adhesive layer and the outer layer were laminated in this order in the thickness direction, and the thickness of each layer was the same as in Example 1. The film was evaluated.
A package was manufactured and evaluated in the same manner as in Example 1, except that this laminated film was used. The results are shown in Table 6.

[Comparative Examples 1-2]
An easy peel layer, a water vapor barrier layer, a first adhesive layer, an oxygen barrier layer, an intermediate layer, a second adhesive layer, and an outer layer were prepared in the same manner as in Example 1, except that the conditions during coextrusion of the resin were changed. were laminated in this order in the thickness direction, and the thickness of each layer was as shown in Table 7. A laminated film (thickness: 180 μm) was produced, and this laminated film was evaluated.
A package was manufactured and evaluated in the same manner as in Example 1, except that this laminated film was used. The results are shown in Table 7.

[Comparative example 3]
By mixing the LDPE (1) (30 parts by mass), the rPP (4) (70 parts by mass), and the AB (0.2 parts by mass) at room temperature, an easy-peel layer forming composition (17) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (17) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 7.

[Comparative example 4]
By mixing the LDPE (1) (30 parts by mass), the rPP (1) (70 parts by mass), and the AB (0.05 parts by mass) at room temperature, an easy-peel layer forming composition (18) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (18) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 7.

[Comparative example 5]
By mixing the LDPE (1) (30 parts by mass), the rPP (1) (70 parts by mass), and the AB (3.2 parts by mass) at room temperature, an easy-peel layer forming composition (19) is prepared. was manufactured.
A laminated film and a package were produced in the same manner as in Example 1, except that this easy-peel layer-forming composition (19) was used instead of the easy-peel layer-forming composition (1). The laminated film and package were evaluated. The results are shown in Table 8.

[Example 21]
A laminated film having the configuration shown in FIG. 2 was manufactured by the procedure shown below.
That is, the temperature of the die was 250° C., the composition for forming an easy peel layer (1), the composition for forming a water vapor barrier layer (1), the acid-modified PP, the Ny6, the MXNy, By coextruding the acid-modified PP and the rPP (2) in this order (coextrusion T-die method), an easy peel layer (thickness 11 μm), a water vapor barrier layer (thickness 28 μm), a first The adhesive layer (thickness 18 μm), the intermediate layer (thickness 40 μm), the oxygen barrier layer (thickness 22 μm), the second adhesive layer (thickness 16 μm) and the outer layer (thickness 45 μm) were formed in this order in the thickness direction. A laminated film (thickness: 180 μm) was obtained. This laminated film was evaluated in the same manner as in Example 1.
A package was manufactured and evaluated in the same manner as in Example 1, except that this laminated film was used. The results are shown in Table 9.

As is clear from the above results, in Examples 1 to 24, the amount of oxygen permeation of the laminated film after retort treatment was 16 cc/(m ² ·day · atm) or less (3 to 16 cc/(m ² ·day · atm) )), and the deterioration of oxygen barrier properties was suppressed in the laminated film after retort treatment. In Examples 1 to 24, the storage stability of the food in the package after retort treatment was good, and the whitening of the bottom material (laminated film) after retort treatment was suppressed. As mentioned above, this was consistent with the fact that the decrease in oxygen barrier properties was suppressed.
In Examples 1 to 24, the oxygen barrier layer in the laminated film contained polyamide having an aromatic ring.

In Examples 1 to 24, no foaming was observed in the oxygen barrier layer in the laminated film, which is because the foaming of the oxygen barrier layer and the resin for forming it was suppressed during the production of the laminated film. It showed that.
In Examples 1 to 24, the ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film was 57.8% or less (5.6 to 57.8%).

In Examples 1 to 24, the content deposition on the sealing surface of the easy peel layer was suppressed in the package after retort treatment.
In Examples 1 to 24, the surface roughness Rsm of the sealing surface of the easy peel layer was 80 μm or more (80 to 800 μm).
In Examples 1 to 24, in the easy peel layer, the content ratio of the antiblocking agent was 0.1% by mass or more (0.1 to 3% by mass) based on 100 parts by mass of the total content of components other than the antiblocking agent. .0% by mass).

In Examples 1 to 24, the original fabric obtained by winding the laminated film had suppressed winding misalignment after being transported for 600 km.
In Examples 1 to 24, the surface roughness Rsm of the sealing surface of the easy peel layer was 800 μm or less (80 to 800 μm).

In Examples 1 to 24, the cuttability of the bottom material was good.
In Examples 1 to 24, the ratio of the thickness of the intermediate layer to the thickness of the laminated film was 22.2% or less (5.6 to 22.2%).

In Examples 1 to 24, the haze of the laminated film was 22% or less (13 to 22%). Among them, in Examples 1 to 16, 18 to 21, and 23 to 25, the haze of the laminated film was 19% or less (13 to 19%), which was particularly low.
In Examples 1 to 16, 18, 19, and 21 to 25, in the easy peel layer, the content ratio of the propylene polymer to the total mass of the easy peel layer was 62 to 78% by mass, and The content ratio of the ethylene polymer was 22 to 38% by mass.
Further, in Examples 1 to 21 and 23 to 25, the density of the ethylene polymer contained in the easy peel layer was 0.938 g/cm ³ or less (0.922 to 0.938 g/cm ³ ). .

In Examples 1 to 22, 24, and 25, the shape stability of the bottom material was high.
In Example 23, the melt tension of the water vapor barrier layer was 0.1 g, but in Examples 1 to 22, 24, and 25, the melt tension of the water vapor barrier layer was 0.5 g or more (0.5 to 3 g). .5g).

In Examples 1 to 23 and 25, the effect of suppressing roughness on the surface of the outer layer of the bottom material after retort treatment was high.
In Example 24, the melting point of the propylene polymer contained in the outer layer was 125°C, but in Examples 1 to 23 and 25, the melting point of the propylene polymer contained in the outer layer was 132°C or higher (132°C). ~148°C).

In Examples 1 to 25, the easy-peel properties of the packages after retort treatment were high.

In Examples 1 to 13 and 15 to 25, the appearance of the bottom material after retort treatment was highly uniform.
In Example 14, the melting point of the propylene polymer contained in the water vapor barrier layer was 125°C, but in Examples 1 to 13 and 15 to 25, the melting point of the propylene polymer contained in the water vapor barrier layer was 138°C. ℃ or higher (138-160℃).

In Examples 1 to 16, 18, 19, and 21 to 25, the unsealability of the packages was good, and in Examples 1 to 15, 18, and 21 to 25, it was particularly good.
In Example 17, in the easy-peel layer, the content ratio of the propylene-based polymer was 58% by mass with respect to the total mass of the easy-peel layer, and the content ratio of the ethylene-based polymer was 42% by mass. % by mass, and the feeling of peeling of the bottom material from the lid material was light. In Example 20, in the easy-peel layer, the content ratio of the propylene-based polymer was 82% by mass with respect to the total mass of the easy-peel layer, and the content ratio of the ethylene-based polymer was 18% by mass. % by mass, and the feeling of peeling of the bottom material from the lid material was heavy.
On the other hand, in Examples 1 to 16, 18, 19, and 21 to 25, in the easy peel layer, the content ratio of the propylene polymer to the total mass of the easy peel layer was 62 to 78 mass. %, and the content of the ethylene polymer was 22 to 38% by mass. Among them, in Examples 1 to 15, 18, and 21 to 25, in the easy peel layer, the content ratio of the propylene polymer to the total mass of the easy peel layer is 66 to 74% by mass, The content ratio of the ethylene polymer was 26 to 34% by mass.
In Examples 1 to 25, the peel strength of the package was 5 to 20 N/15 mm, and in particular, in Examples 1 to 16, 18, 19, and 21 to 25, it was 8 to 16 N/15 mm. In Examples 1 to 15, 18, and 21 to 25, it was 10 to 14 N/15 mm.

A comparison between Example 1 and Example 25 confirmed that the laminated film and package had the desired properties even if the order of lamination of the oxygen barrier layer and the intermediate layer was different.

On the other hand, in Comparative Examples 1 to 5, the laminated film or package did not have the desired properties.

In Comparative Example 1, foaming was observed in the oxygen barrier layer in the laminated film, which indicates that the foaming of the oxygen barrier layer or the resin for forming it was not suppressed during the production of the laminated film. It was showing. Further, due to the foaming in the oxygen barrier layer, the effect of suppressing whitening of the bottom material was insufficient.
In Comparative Example 1, the ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film was 62.2%.

In Comparative Example 2, the oxygen permeation amount of the laminated film after retort treatment was 110 cc/(m ² ·day · atm), and the decrease in oxygen barrier properties was not suppressed in the laminated film after retort treatment. In Comparative Example 2, the storage stability of the packaged food after retort treatment was insufficient, and this result was consistent with the fact that the decrease in oxygen barrier properties was not suppressed.
In Comparative Example 2, the oxygen barrier layer in the laminated film contained polyamide having an aromatic ring, but the ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film was 1.7%. Ta.

In Comparative Example 3, the easy peelability of the package after retort treatment was insufficient.
In Comparative Example 3, the melting point of the propylene polymer contained in the water vapor barrier layer was 125°C.

In Comparative Example 4, in the package after retort treatment, deposition of contents on the sealing surface of the easy peel layer was not suppressed.
In Comparative Example 4, the surface roughness Rsm of the sealing surface of the easy peel layer was 50 μm.
In Comparative Example 4, in the easy peel layer, the content of the antiblocking agent was 0.05% by mass with respect to 100 parts by mass of the total content of components other than the antiblocking agent.

In Comparative Example 5, the original fabric obtained by winding up the laminated film was not suppressed from winding misalignment after being transported for 600 km.
In Comparative Example 5, the surface roughness Rsm of the sealing surface of the easy peel layer was 820 μm.

The present invention provides a laminated film having an easy-peel layer that suppresses whitening and deterioration of oxygen barrier properties even when subjected to heat treatment, has heat resistance, and is resistant to adhesion of liquids generated from foods; A package using a laminated film can be provided.

1... Laminated film 1'... Bottom material 2... Laminated film 8... Lid material 9... Item to be packaged 10... Packaging body 11... Easy peel layer 12... Water vapor Barrier layer 13... Oxygen barrier layer 14... Intermediate layer 15... Outer layer 16... Adhesive layer 161... First adhesive layer 162... Second adhesive layer

Claims (14)

A laminated film comprising at least an easy peel layer and an oxygen barrier layer,
The easy peel layer contains a propylene polymer having a melting point of 130° C. or higher,
The surface roughness Rsm of the surface of the easy peel layer opposite to the oxygen barrier layer side is 80 to 800 μm,
The oxygen barrier layer includes polyamide having an aromatic ring,
Immediately after the laminated film was retorted at a temperature of 121°C for 30 minutes, the amount of oxygen permeation of the laminated film was measured in accordance with ASTM D3985 under conditions of a temperature of 23°C and a relative humidity of 60%. 100cc/( ^m2・day・atm) or less,
A laminated film, wherein the ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film is 60% or less. A laminated film comprising at least an easy peel layer and an oxygen barrier layer,
The easy peel layer contains a propylene polymer having a melting point of 130° C. or higher and an anti-blocking agent,
In the easy-peel layer, the content of the anti-blocking agent is 0.1 parts by mass or more with respect to 100 parts by mass of the total content of components other than the anti-blocking agent,
The oxygen barrier layer includes polyamide having an aromatic ring,
Immediately after the laminated film was retorted at a temperature of 121°C for 30 minutes, the amount of oxygen permeation of the laminated film was measured in accordance with ASTM D3985 under conditions of a temperature of 23°C and a relative humidity of 60%. 100cc/( ^m2・day・atm) or less,
A laminated film, wherein the ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film is 60% or less. The laminated film according to claim 1 or 2, wherein the laminated film further comprises an intermediate layer adjacent to the oxygen barrier layer and on the easy peel layer side or the opposite side thereof. The laminated film further includes a water vapor barrier layer,
The laminated film according to claim 1 or 2, wherein the water vapor barrier layer contains a propylene polymer having a melting point of 130°C or higher. The easy peel layer further contains an ethylene polymer,
In the easy-peel layer, the content ratio of the propylene-based polymer to the total mass of the easy-peel layer is 60 to 80% by mass,
The laminated film according to claim 1 or 2, wherein the content of the ethylene polymer in the easy-peel layer is 19 to 39% by mass with respect to the total mass of the easy-peel layer. The laminated film further includes an outer layer as the outermost layer on the opposite side from the easy peel layer,
the outer layer contains a propylene polymer,
The propylene-based polymer is either or both of a propylene homopolymer with a melting point of 130° C. or higher and a propylene-ethylene copolymer with a melting point of 130° C. or higher,
The laminated film according to claim 1 or 2, wherein in the outer layer, a content ratio of the propylene polymer to the total mass of the outer layer is 90% by mass or more. The laminated film according to claim 5, wherein the ethylene polymer included in the easy peel layer is low density polyethylene with a melting point of 120°C or less. The laminated film according to claim 5, wherein the ethylene polymer included in the easy peel layer is low density polyethylene having a density of 0.940 or less. The laminated film according to claim 4, wherein the water vapor barrier layer has a melt tension of 0.2 g or more. The laminated film according to claim 4, wherein the water vapor barrier layer contains one type of the propylene-based polymer or two or more types of the propylene-based polymers having different melt tensions. The laminated film according to claim 3, wherein the intermediate layer contains polyamide having no aromatic ring. The laminated film according to claim 1 or 2, wherein the laminated film has a haze of 20% or less. The laminated film according to claim 1 or 2, wherein the laminated film is for packaging retort food. A package comprising the laminated film according to claim 1 or 2.

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