JP7251111B2 - Multilayer film and package - Google Patents

Description

The present invention relates to multilayer films and packages.

A package in which a content is placed on a hard tray and the content is sealed with a film is called a skin pack. In the skin pack, the film, that is, the film for the skin pack is transparent, so that the contents can be easily visually recognized through the film. In addition, the film for skin pack is soft and can be brought into close contact with the contents without causing wrinkles by evacuating the storage part in the skin pack. Since the skin pack is provided with a hard tray, the contents can be displayed in an upright position without displacement. In view of such characteristics, skin packs are mainly used as packaging bodies for foods.

On the other hand, packaging machines for skin packs are not yet widely used, and skin packs are expensive. On the other hand, conventional deep-drawing packaging has been widely used for packaging foods and pharmaceuticals. Deep draw packaging uses a bottom material film having a recessed storage part, stores an object in this storage part, and seals it with a thin lid material film (for example, Patent Document 1). Deep draw packaging is low cost due to the widespread availability of thermo draw packaging machines.

JP-A-10-119193

However, deep draw packages (including vacuum packages), as described above, use bottom and lid films, which are multi-layered but thin and flexible. Therefore, unlike skin packs, deep-drawn packages are not suitable for standing display.

The present invention has been made in view of the above circumstances, and provides a novel packaging body that can be produced using a deep drawing packaging machine and can be displayed on a stand, and a film for manufacturing the packaging body. The challenge is to

In order to solve the above problems, the present invention employs the following configuration.
[1]. A multilayer film comprising an outer layer containing polyester and a sealant layer containing a resin having a melting point of less than 100° C., wherein the outer layer has a thickness of 25 to 170 μm.
[2]. The multilayer film according to [1], further comprising an intermediate layer between the outer layer and the sealant layer.
[3]. [1] or [2], wherein the resin having a melting point of less than 100° C. is one or more selected from the group consisting of ethylene-methacrylic acid copolymers, ethylene-vinyl acetate copolymers and ionomers; Multilayer film according to.
[4]. [1] to [3], wherein the sealant layer further contains one or more selected from the group consisting of polypropylene and ethylene-propylene copolymer, in addition to the resin having a melting point of less than 100 ° C. A multilayer film according to any one of the clauses.
[5]. The multilayer film according to any one of [1] to [4], wherein the ratio of the thickness of the outer layer to the thickness of the multilayer film is 50% or more.

[6]. The multilayer film according to any one of [1] to [5], wherein the multilayer film has a thickness of 70 μm or more.
[7]. A package comprising the multilayer film according to any one of [1] to [6].
[8]. The package comprises a lid material and a bottom material, the lid material is made of the multilayer film, and the package is a deep-drawn package formed by sealing the lid material and the bottom material. The package according to [7].
[9]. The package according to [8], wherein the lid member has a thickness of 100 μm or more, and the bottom member has a thickness of 160 μm or less.

According to the present invention, a novel packaging body that can be produced using a deep drawing packaging machine, can be tightly attached to a contained object without causing wrinkles, and can be displayed on a stand, and for manufacturing the packaging body of films are provided.

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

<<Multilayer film>>
A multilayer film according to one embodiment of the present invention comprises an outer layer containing polyester and a sealant layer containing a resin having a melting point of less than 100° C. The outer layer has a thickness of 25 to 170 μm.
The multi-layered film of the present embodiment can form a package together with other films using a conventional deep-drawing packaging machine. As such a package, it is possible to manufacture a package that can be vacuum-sealed and that can be displayed on a stand. In this specification, the term “standing display of the package” refers to the display surface of the package without contacting the flat surface of the package (more specifically, the exposed surface of the lid or bottom material). means that the edges of the package are in contact and the package is displayed in an upright position.
The multi-layer film of the present embodiment enables the low-cost production of non-skin pack packages that have the same characteristics as conventional skin packs by using a deep-drawing packaging machine without using a special packaging machine.

The present invention will be described in detail below with reference to the drawings. In the drawings used in the following description, in order to make it easier to understand the features of the present invention, there are cases where the main parts are enlarged for convenience, and the dimensional ratio of each component is the same as the actual one. not necessarily.

FIG. 1 is a cross-sectional view schematically showing a multilayer film according to one embodiment of the invention.
The multilayer film 1 shown here comprises an outer layer 12 and a sealant layer 11 . In the multilayer film 1, the outer layer 12 is one of the outermost layers, and the sealant layer 11 is the other outermost layer.
Furthermore, the multilayer film 1 comprises an intermediate layer 13 between the outer layer 12 and the sealant layer 11 . That is, the multilayer film 1 includes a sealant layer 11 , an intermediate layer 13 placed on the sealant layer 11 , and an outer layer 12 placed on the intermediate layer 13 .

Further, the intermediate layer 13 includes, from the sealant layer 11 side to the outer layer 12 side, an adhesive layer 139, a first resin layer 131 arranged on the adhesive layer 139, and a first resin layer 131 arranged on the first resin layer 131. It has a second resin layer 132 and an adhesive layer 139 arranged on the second resin layer 132, and consists of a plurality of layers.
In this specification, the "adhesive layer on the sealant layer side" may be referred to as the "first adhesive layer", and the "adhesive layer on the outer layer side" may be referred to as the "second adhesive layer".

<Sealant layer>
The sealant layer 11 contains a resin having a melting point of less than 100°C.
The sealant layer 11 may contain only a resin having a melting point of less than 100° C. (that is, may be made of a resin having a melting point of less than 100° C.), or may contain a resin having a melting point of less than 100° C. and a resin having a melting point of less than 100° C. It may contain other components (in this specification, may be referred to as "other components") (that is, it consists of a resin having a melting point of less than 100 ° C. and the other components. may be used).

The resin having a melting point of less than 100° C. contained in the sealant layer 11 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. may Among them, the resin is preferably a copolymer.

Although the melting point of the resin contained in the sealant layer 11 is not particularly limited as long as it is less than 100°C, it is preferably 95°C or less, more preferably 90°C or less. When the melting point of the resin is in such a range, the sealing strength is increased when the multilayer film 1 is heated and sealed.

The lower limit of the melting point of the resin contained in the sealant layer 11 is not particularly limited. For example, the melting point of the resin is preferably 80° C. or higher in terms of easier availability of the resin.

Preferred examples of the resin contained in the sealant layer 11 include ethylene-methacrylic acid copolymer, ethylene-vinyl acetate copolymer, and ionomer.
The ionomer may be an ethylenic ionomer. That is, preferred examples of the resin contained in the sealant layer 11 include copolymers of ethylene and other monomers, such as ethylene-methacrylic acid copolymers, ethylene-vinyl acetate copolymers, and ethylene-based ionomers. (that is, an ethylene-based copolymer). Non-ethylene ionomers include, for example, styrene ionomers.

The resin (resin having a melting point of less than 100° C.) contained in the sealant layer 11 may be of only one type, or may be of two or more types. , can be selected arbitrarily according to the purpose.

The resin contained in the sealant layer 11 is preferably one or more selected from the group consisting of ethylene-methacrylic acid copolymer, ethylene-vinyl acetate copolymer and ionomer.

The other components contained in the sealant layer 11 are not particularly limited and can be arbitrarily selected according to 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 having a melting point of 100° C. or higher.
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.
More specific examples of the other components that are resin components include polyolefins such as polypropylene; and olefinic copolymers such as ethylene-propylene copolymers. The sealant layer 11 containing these other components (resin component) further improves easy peelability due to cohesive failure.

Examples of the other components, which are non-resin components, include additives known in the art.
Examples of the additives include antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, viscosity reducers, thickeners, heat stabilizers, lubricants, infrared absorbers, ultraviolet absorbers, antifogging agents, and the like. is mentioned.

The other components contained in the sealant layer 11 may be only one type, or may be two or more types, and when there are two or more types, the combination and ratio thereof may be arbitrarily depending on the purpose. You can choose.

In terms of the sealant layer 11 having good easy peelability, the other components contained in the sealant layer 11 are one or more selected from the group consisting of polypropylene and ethylene-propylene copolymers (this In the specification, it may be abbreviated as "easy peeling resin"). That is, the sealant layer 11 preferably contains one or more selected from the group consisting of polypropylene and ethylene-propylene copolymer, in addition to the resin having a melting point of less than 100°C.

When the sealant layer 11 does not contain the easy-peel resin as the other component, the content ratio of the resin having a melting point of less than 100° C. to the total mass of the sealant layer 11 in the sealant layer 11 is It is preferably 85% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, for example, 97% by mass or more, or 99% by mass or more. good too. When the ratio is equal to or higher than the lower limit, the sealing strength increases when the multilayer film 1 is heated and sealed.
The upper limit of the ratio is not particularly limited. For example, the proportion may be 100% by mass or less.

In other words, when the sealant layer 11 does not contain the easy peel resin as the other component, the content ratio of the other component in the sealant layer 11 to the total mass of the sealant layer 11 is It is preferably 15% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less, for example, 3% by mass or less and 1% by mass or less. good too. When the ratio is equal to or less than the upper limit, the sealing strength increases when the multilayer film 1 is heated and sealed.
The lower limit of the ratio is not particularly limited. For example, the ratio may be 0% by mass or more.

When the sealant layer 11 contains the easy peel resin as the other component, a resin having a melting point of less than 100 ° C. and the easy peel resin in the sealant layer 11 with respect to the total mass of the sealant layer 11 and the total content ratio is preferably 85% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, for example, 97% by mass or more, and Any of 99 mass % or more may be sufficient. When the ratio is equal to or higher than the lower limit, when the multilayer film 1 is sealed by heating, the sealing strength becomes high and the easy peel property of the sealed portion becomes high.
The upper limit of the ratio is not particularly limited. For example, the proportion may be 100% by mass or less.

In other words, when the sealant layer 11 contains the easy-peel resin as the other component, the other components other than the easy-peel resin in the sealant layer 11 with respect to the total mass of the sealant layer 11 is preferably 15% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less, for example, 3% by mass or less and 1% by mass. It may be any of the following: When the ratio is equal to or less than the upper limit, the sealing strength increases when the multilayer film 1 is heated and sealed.
The lower limit of the ratio is not particularly limited. For example, the ratio may be 0% by mass or more.

When the sealant layer 11 contains the easy peel resin as the other component, in the sealant layer 11, the total content of the resin having a melting point of less than 100 ° C. and the easy peel resin, The content ratio of the resin having a melting point of less than 100° C. is preferably 60 to 90 mass %.

The sealant layer 11 may consist of one layer (single layer), or may consist of multiple layers of two or more layers. When the sealant layer 11 is composed of multiple layers, these multiple layers may be the same or different, 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, not only in the case of the sealant layer 11, but "a plurality of layers may be the same or different" means "all the layers may be the same, or all the layers may be It may be different, and only a part of the layers may be the same", and further, "a plurality of layers are different from each other" means that "at least one of the constituent material and thickness of each layer is different from each other". means that

The thickness T ₁₁ of the sealant layer 11 is preferably 3 to 100 μm, more preferably 5 to 60 μm, regardless of whether the multilayer film 1 is used as a lid material or a bottom material of a package described later. is more preferable, and may be, for example, 5 to 40 μm or 5 to 20 μm. When the thickness T11 of the sealant layer ₁₁ is equal to or greater than the lower limit, the strength of the sealant layer 11 is further increased. When the thickness _T11 of the sealant layer 11 is equal to or less than the upper limit, the sealant layer 11 is prevented from becoming excessively thick.
Here, the "thickness of the sealant layer 11" means the thickness of the entire sealant layer 11. For example, the thickness of the sealant layer 11 consisting of a plurality of layers is the total thickness of all layers constituting the sealant layer 11. means the thickness of

An exposed surface 11a of the sealant layer 11 opposite to the adhesive layer 139 side (in this specification, may be referred to as a "first surface") 11a is a sealing surface.

<Outer layer>
Outer layer 12 comprises polyester.
The outer layer 12 may contain only polyester (that is, may be made of polyester), or polyester and other components (hereinafter referred to as "other components"). (that is, it may consist of polyester and the other components).

The polyester included in the outer layer 12 is a polymer corresponding to a polycondensate of dicarboxylic acid and glycol (diol compound), and has structural units derived from dicarboxylic acid and structural units derived from glycol.

The dicarboxylic acid is not particularly limited as long as it is a compound having two carboxy groups (-C(=O)-OH).
More specifically, the dicarboxylic acid includes, for example, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sodiumsulfoisophthalic acid, phthalic acid, and other aromatic acids. chain aliphatic dicarboxylic acids such as oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid and fumaric acid; and cycloaliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid.
Among these, the dicarboxylic acid is preferably terephthalic acid, isophthalic acid or naphthalenedicarboxylic acid.

In the glycol, one hydrogen atom (a total of two hydrogen atoms (-H)) bonded to two different carbon atoms in the hydrocarbon is substituted with a hydroxyl group (-OH). It is not particularly limited as long as it is a compound.
As the glycol, more specifically, for example, chain aliphatic diols such as ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, and neopentyl glycol; cycloaliphatic diols such as cyclohexanedimethanol; , aromatic diols such as bisphenol S; and polyoxyethylene glycols such as diethylene glycol and polyethylene glycol.
Among these, the glycol is preferably ethylene glycol.

In the polyester, the structural units derived from a dicarboxylic acid and the structural units derived from a glycol may be either one type or two or more types, and when there are two or more types , their combination and ratio can be arbitrarily selected according to the purpose.

As the polyester, more specifically, for example, polyethylene terephthalate (herein sometimes abbreviated as "PET"), polybutylene terephthalate (herein sometimes abbreviated as "PBT") , polybutylene succinate, polyethylene naphthalate, unmodified polyester such as polybutylene naphthalate; glycol-modified polyethylene terephthalate (herein sometimes abbreviated as "PETG"), etc. In the unmodified polyester, glycol Examples include modified polyesters having two or more structural units derived from.

The polyester contained in the outer layer 12 may be of only one type, or may be of two or more types, and when two or more types are used, the combination and ratio thereof can be arbitrarily selected according to the purpose.

More preferably, the polyester contained in the outer layer 12 is PET.

The other components included in the outer layer 12 are not particularly limited and can be arbitrarily selected according to 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 polyester.
Examples of the other component, which is a non-resin component, include the same additives as the other components included in the sealant layer 11 .

The other components contained in the outer layer 12 may be only one kind, or may be two or more kinds, and when there are two or more kinds, the combination and ratio thereof are arbitrarily selected according to the purpose. can.

The ratio of the polyester content in the outer layer 12 to the total weight of the outer layer 12 is preferably 85% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. , 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, the rigidity of the multilayer film 1 and the package constructed using the multilayer film 1 becomes higher, and the package is more suitable for standing display. Become.
The upper limit of the ratio is not particularly limited. For example, the proportion may be 100% by mass or less.

In other words, the ratio of the content of the other components in the outer layer 12 to the total weight of the outer layer 12 is preferably 15% by mass or less, more preferably 10% by mass or less, and 5% by mass or less. For example, it may be either 3% by mass or less or 1% by mass or less. When the ratio is equal to or less than the upper limit, the rigidity of the multilayer film 1 and the package constructed using the multilayer film 1 is increased, and the package is more suitable for standing display. Become.
The lower limit of the ratio is not particularly limited. For example, the ratio may be 0% by mass or more.

The outer layer 12 may consist of one layer (single layer), or may consist of two or more layers. When the outer layer 12 is composed of multiple layers, these multiple layers may be the same or different, 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 T ₁₂ of the outer layer 12 is 25-170 μm.
When the multilayer film 1 is used as a lid material for a package described later, the thickness _T12 of the outer layer 12 is preferably 70 to 170 μm, for example, 85 to 170 μm, 100 to 170 μm, 110 to 165 μm, and 110 to 160 μm. In the above case, when the thickness _T12 of the outer layer 12 is equal to or greater than the lower limit value, the rigidity of the multilayer film 1 and the package constructed using the multilayer film 1 is increased, and the package can be displayed on a stand. be suitable for When the thickness _T12 of the outer layer 12 is equal to or less than the upper limit, the sealing properties of the multilayer film 1 are further improved.
As used herein, the “thickness of the outer layer 12” means the thickness of the entire outer layer 12. For example, the thickness of the outer layer 12 consisting of a plurality of layers refers to the total thickness of all layers constituting the outer layer 12. means

When the multilayer film 1 is used as the bottom material of a package described later, the thickness _T12 of the outer layer 12 is preferably 25 to 100 μm, for example, either 25 to 80 μm or 25 to 60 μm. There may be. In the above case, when the thickness _T12 of the outer layer 12 is equal to or greater than the lower limit, the strength of the outer layer 12 becomes higher. When the thickness T12 of the outer layer ₁₂ is equal to or less than the upper limit, the adhesion of the package constructed using the multilayer film 1 to the contents is further improved.

When the multilayer film 1 is used as a lid material for a package, which will be described later, the ratio of the thickness T12 of the outer layer ₁₂ to the thickness _T1 of the multilayer film 1 ( _T12 / _T1 ×100) is particularly limited. However, it is preferably 50% or more, more preferably 54% or more, even more preferably 58% or more. When the ratio is equal to or higher than the lower limit, the rigidity of the multilayer film 1 and the package constructed using the multilayer film 1 becomes higher, and the package is more suitable for standing display. Become.

When the multilayer film 1 is used as a lid material for a package, which will be described later, the ratio of the thickness _T12 of the outer layer ₁₂ to the thickness T1 of the multilayer film 1 is preferably 80% or less, preferably 76%. It is more preferably 72% or less, more preferably 72% or less. When the ratio is equal to or less than the upper limit, the sealing properties of the multilayer film 1 are further improved.

The ratio of the thickness _T12 of the outer layer ₁₂ to the thickness T1 of the multilayer film 1 can be appropriately adjusted within a range set by arbitrarily combining the preferred lower and upper limits described above. For example, in one embodiment, the percentage is preferably 50-80%, more preferably 54-76%, even more preferably 58-72%. However, these are examples of preferred ratios.

When the multilayer film 1 is used as the bottom material of a package described later, the ratio of the thickness T12 of the outer layer ₁₂ to the thickness _T1 of the multilayer film 1 ( _T12 / _T1 ×100) is particularly limited. However, it is preferably 25 to 65%, more preferably 28 to 60%, even more preferably 30 to 55%. When the ratio is equal to or higher than the lower limit, the strength of the outer layer 12 becomes higher. When the ratio is equal to or less than the upper limit, the adhesion of the package formed using the multilayer film 1 to the contents is further improved.
In this specification, when the multilayer film 1 is used as a bottom material, the multilayer film may be denoted by reference numeral 2 and the outer layer 12 may be denoted by reference numeral 12', as will be described later.

<Middle layer>
The intermediate layer 13 imparts functions to the multilayer film 1 separately from the sealant layer 11 and the outer layer 12 . The multilayer film 1 does not have to include the intermediate layer 13, but the presence of the intermediate layer 13 makes it more functional.

[First resin layer]
The first resin layer 131 in the intermediate layer 13 contains a first resin.
Examples of the first resin layer 131 include a protective layer that provides the multilayer film 1 with high puncture strength, pinhole resistance, and the like.

When the first resin layer 131 is the protective layer, the first resin layer 131 preferably contains polyamide such as nylon as the first resin.
Examples of the nylon include 4-nylon, 6-nylon, 7-nylon, 11-nylon, 12-nylon, 46-nylon, 66-nylon, 69-nylon, 610-nylon, 611-nylon, and 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, 6-nylon and 12-nylon (nylon 6/12), 6-nylon and 612 nylon copolymer, 6-nylon and 6T-nylon copolymer, 6-nylon and 6I-nylon copolymer, 6-nylon and 610-nylon copolymer with 66-nylon, 12-nylon copolymer of 6-nylon and 66-nylon (nylon 6/66/12), copolymer of 6-nylon and 66-nylon and 612-nylon, 66 - copolymer of nylon and 6T-nylon, copolymer of 66-nylon and 6I-nylon, copolymer of 6T-nylon and 6I-nylon, copolymer of 66-nylon, 6T-nylon and 6I-nylon, etc. .

Regardless of whether the first resin is polyamide, the first resin layer 131 may contain only the first resin (that is, may be made of the first resin), or may contain the first resin. It may contain a resin and other components (in this specification, may be referred to as "other components") (that is, it consists of the first resin and the other components). may be used).

The first resin contained in the first resin layer 131 may be of only one type, or may be of two or more types. When there are two or more types, the combination and ratio thereof may be arbitrary depending on the purpose. can be selected to

When first resin layer 131 contains polyamide, it may or may not contain resin other than polyamide.
A resin other than polyamide contained in the first resin layer 131 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. .
The resin other than polyamide contained in the first resin layer 131 is not particularly limited and can be arbitrarily selected according to the purpose.

The other component contained in the first resin layer 131 is not particularly limited as long as it is a non-resin component.
Examples of the other component, which is a non-resin component, include the same additives as the other components included in the sealant layer 11 .

The other components contained in the first resin layer 131 may be of only one kind, or may be of two or more kinds. Can be selected arbitrarily.

Regardless of whether the first resin is polyamide or not, the ratio of the content of the first resin in the first resin layer 131 to the total mass of the first resin layer 131 is preferably 85% 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 proportion is equal to or higher than the lower limit, the effect of using the first resin can be obtained more remarkably.
The upper limit of the ratio is not particularly limited. For example, the proportion may be 100% by mass or less.

In other words, the ratio of the content of the other components in the first resin layer 131 to the total mass of the first resin layer 131 is preferably 15% by mass or less, more preferably 10% by mass or less. It is preferably 5% by mass or less, more preferably 5% by mass or less, and may be either 3% by mass or less or 1% by mass or less. When the proportion is equal to or less than the upper limit, the effect of using the first resin can be obtained more remarkably.
The lower limit of the ratio is not particularly limited. For example, the ratio may be 0% by mass or more.

When the first resin layer 131 contains polyamide, the content ratio of the polyamide in the first resin layer 131 to the total mass of the first resin layer 131 is preferably 85% by mass or more, and 90% by mass or more. and more preferably 95% by mass or more. For example, it may be either 97% by mass or more or 99% by mass or more. When the proportion is equal to or higher than the lower limit, the effect of using polyamide can be obtained more remarkably.
The upper limit of the ratio is not particularly limited. For example, the proportion may be 100% by mass or less.

The first resin layer 131 may be composed of one layer (single layer), or may be composed of multiple layers of two or more layers. When the first resin layer 131 is composed of multiple layers, these multiple layers may be the same or different, 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 T ₁₃₁ of the first resin layer 131 is determined regardless of whether the multilayer film 1 is for a lid material or a bottom material of a package described later, and whether the first resin is polyamide. However, it is preferably 3 to 50 μm, more preferably 4 to 25 μm, and may be, for example, 5 to 10 μm. When the thickness T ₁₃₁ of the first resin layer 131 is equal to or greater than the lower limit, the strength of the first resin layer 131 becomes higher. Since the thickness T ₁₃₁ of the first resin layer 131 is equal to or less than the upper limit value, the excessive thickness of the first resin layer 131 is suppressed.
Here, the “thickness of the first resin layer 131” means the thickness of the entire first resin layer 131. For example, the thickness of the first resin layer 131 consisting of a plurality of layers means means the total thickness of all the layers that make up the

[Second resin layer]
The second resin layer 132 in the intermediate layer 13 contains a second resin.
Examples of the second resin layer 132 include an oxygen barrier layer that imparts a strong oxygen barrier property (in other words, a property of suppressing permeation of oxygen gas) to the multilayer film 1 .

When the second resin layer 132 is the oxygen barrier layer, examples of the second resin included in the second resin layer 132 include saponified ethylene-vinyl acetate copolymer (abbreviated as “EVOH” in this specification). may be used), etc.

The second resin layer 132 may contain only the second resin (that is, may consist of the second resin) regardless of whether the second resin is EVOH, or may contain the second resin. It may contain a resin and other components (in this specification, may be referred to as "other components") (that is, it consists of the second resin and the other components). may be used).

The second resin contained in the second resin layer 132 may be of only one type, or may be of two or more types. When there are two or more types, the combination and ratio thereof may be arbitrary depending on the purpose. can be selected to

When the second resin layer 132 contains EVOH, it may or may not contain a resin other than EVOH.
The resin other than EVOH contained in the second resin layer 132 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. .
The resin other than EVOH contained in the second resin layer 132 is not particularly limited and can be arbitrarily selected according to the purpose.

The other component contained in the second resin layer 132 is not particularly limited as long as it is a non-resin component.
Examples of the other component, which is a non-resin component, include the same additives as the other components included in the sealant layer 11 .

The other components contained in the second resin layer 132 may be only one type, or may be two or more types, and when there are two or more types, the combination and ratio thereof may be changed depending on the purpose. Can be selected arbitrarily.

Regardless of whether the second resin is EVOH or not, the content ratio of the second resin in the second resin layer 132 to the total mass of the second resin layer 132 is preferably 85% 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 higher than the lower limit, the effect of using the second resin can be obtained more remarkably.
The upper limit of the ratio is not particularly limited. For example, the proportion may be 100% by mass or less.

In other words, the ratio of the content of the other components in the second resin layer 132 to the total mass of the second resin layer 132 is preferably 15% by mass or less, more preferably 10% by mass or less. It is preferably 5% by mass or less, more preferably 5% by mass or less, and may be either 3% by mass or less or 1% by mass or less. When the ratio is equal to or less than the upper limit, the effect of using the second resin can be obtained more remarkably.
The lower limit of the ratio is not particularly limited. For example, the ratio may be 0% by mass or more.

When the second resin layer 132 contains EVOH, the ratio of the EVOH content in the second resin layer 132 to the total mass of the second resin layer 132 is preferably 85% by mass or more, and 90% by mass or more. and more preferably 95% by mass or more. For example, it may be either 97% by mass or more or 99% by mass or more. When the ratio is equal to or higher than the lower limit, the effect of using EVOH can be obtained more remarkably.
The upper limit of the ratio is not particularly limited. For example, the proportion may be 100% by mass or less.

The second resin layer 132 may be composed of one layer (single layer), or may be composed of multiple layers of two or more layers. When the second resin layer 132 is composed of multiple layers, these multiple layers may be the same or different, 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 T ₁₃₂ of the second resin layer 132 is determined regardless of whether the multilayer film 1 is used as a lid material or a bottom material of a package described later, and whether the second resin is EVOH or not. It is preferably 3 to 20 μm, more preferably 3 to 15 μm, even more preferably 5 to 10 μm. When the thickness _T132 of the second resin layer 132 is equal to or greater than the lower limit value, the strength of the second resin layer 132 is further increased (higher functional expression can be expected). Since the thickness T ₁₃₂ of the second resin layer 132 is equal to or less than the upper limit value, the second resin layer 132 is prevented from becoming excessively thick.
Here, the “thickness of the second resin layer 132” means the thickness of the entire second resin layer 132. For example, the thickness of the second resin layer 132 consisting of a plurality of layers means means the total thickness of all the layers that make up the

[Adhesion layer]
Adhesive layer 139 in intermediate layer 13 contains an adhesive.
Adhesive layer 139 adheres the two adjacent layers on both sides thereof. In the multilayer film 1, an adhesive layer (first adhesive layer) 139 disposed between the sealant layer 11 and the first resin layer 131 bonds the sealant layer 11 and the first resin layer 131, An adhesive layer (second adhesive layer) 139 arranged between the layer 132 and the outer layer 12 bonds the second resin layer 132 and the outer layer 12 together.
These two adhesive layers 139 may be the same or different.

The adhesive contained in the adhesive layer 139 is not particularly limited as long as it can adhere two layers to be adhered with sufficient strength.
Examples of the adhesive include adhesive resins such as olefin-based resins (that is, polymers of olefins that are one or more monomers).

More specifically, the olefin-based resin includes, for example, an ethylene-based copolymer, a propylene-based copolymer, a butene-based copolymer, and the like, and may be a polyolefin having a polar group.
The ethylene-based copolymer is a copolymer of ethylene and a monomer other than ethylene.
The propylene-based copolymer is a copolymer of propylene and a monomer other than propylene.
The butene-based copolymer is a copolymer of butene and a monomer other than butene.

Examples of the ethylene-based copolymer include copolymers of ethylene and a vinyl group-containing monomer.
Copolymers of ethylene and vinyl group-containing monomers include, for example, maleic anhydride graft-modified linear low-density polyethylene (herein sometimes abbreviated as "LLDPE-g-MAH"), ethylene -Vinyl acetate copolymer (in this specification, sometimes abbreviated as "EVA resin"), ethylene-methyl methacrylate copolymer (in this specification, sometimes abbreviated as "EMMA resin") ), ethylene-ethyl acrylate copolymer (in this specification, sometimes abbreviated as "EEA resin"), ethylene-methyl acrylate copolymer (in this specification, abbreviated as "EMA resin" ), ethylene-ethyl acrylate-maleic anhydride copolymer (in this specification, sometimes abbreviated as "E-EA-MAH resin"), ethylene-acrylic acid copolymer (in this specification may be abbreviated as "EAA resin"), ethylene-methacrylic acid copolymer (in this specification, may be abbreviated as "EMAA resin"), ionomer (in this specification, "ION may be abbreviated as "resin"), ethylene-based thermoplastic elastomers, and the like. The ION resin means a copolymer of ethylene and a small amount of acrylic acid or methacrylic acid that has an ion-bridged structure through salt formation between an acid moiety and a metal ion.

The adhesive layer 139 may contain only an adhesive (that is, may consist of an adhesive), or may include an adhesive and other components (in this specification, “other components”). ) (that is, it may consist of an adhesive and the other components).

The adhesive layer 139 may contain only one kind of adhesive, or two or more kinds thereof, and when two or more kinds of adhesives are contained, the combination and ratio thereof can be arbitrarily selected according to the purpose. .

The other components included in the adhesive layer 139 are not particularly limited and can be arbitrarily selected according to the purpose, and may be, for example, either a resin component or a non-resin component.

The other components contained in the adhesive layer 139 may be of only one type, or may be of two or more types. When there are two or more types, the combination and ratio thereof may be arbitrarily selected depending on the purpose. You can choose.

The content ratio of the adhesive in the adhesive layer 139 to the total mass of the adhesive layer 139 may be, for example, 85 to 100% by mass.
In other words, the content ratio of the other components in the adhesive layer 139 with respect to the total mass of the adhesive layer 139 may be 0 to 15% by mass.

The adhesive layer 139 may consist of one layer (single layer), or may consist of two or more layers. When the adhesive layer 139 is composed of multiple layers, these multiple layers may be the same or different, 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 139 is preferably 2 to 20 μm, more preferably 3 to 15 μm, regardless of whether the multilayer film 1 is used as a cover material or a bottom material of a package described later. It is preferably 4 to 10 μm, more preferably 4 to 10 μm. When the thickness of the adhesive layer 139 is equal to or greater than the lower limit value, the adhesive strength between the two layers to be adhered becomes higher. Since the thickness of the adhesive layer 139 is equal to or less than the upper limit value, it is possible to prevent the adhesive layer 139 from becoming excessively thick.
Here, the “thickness of the adhesive layer 139” refers to the thickness of the entire adhesive layer 139 (for example, the thickness of the entire adhesive layer 139 disposed between the sealant layer 11 and the first resin layer 131, 2 the thickness of the entire adhesive layer 139 disposed between the resin layer 132 and the outer layer 12), for example, the thickness of the adhesive layer 139 consisting of multiple layers means the thickness of all the layers constituting the adhesive layer 139 means the total thickness of

The thickness _T1 of the multilayer film 1 can be arbitrarily selected according to the purpose and is not particularly limited.
For example, if the multilayer film 1 is used as a lid material and a deep-drawing packaging machine is used to manufacture a package that can be vertically displayed from the multilayer film 1, the thickness _T1 of the multilayer film 1 is For example, it is preferably 70 μm or more, more preferably 100 μm or more, still more preferably 140 μm or more, and particularly preferably 180 μm or more. When the thickness _T1 of the multilayer film 1 is within such a range, the rigidity of the multilayer film 1 and the package constructed using the multilayer film 1 is increased, and the package can be displayed upright. is more suitable for
The package will be explained in detail later.

For example, when multilayer film 1 is used as a bottom material and a package that can be vertically displayed is manufactured from multilayer film 1 using a deep drawing packaging machine, thickness _T1 of multilayer film 1 is For example, it is preferably 70 μm or more, and may be either 85 μm or more or 125 μm or more. When the thickness _T1 of the multilayer film 1 is within such a range, the strength of the multilayer film 1 becomes higher.

The upper limit of the thickness _T1 of the multilayer film 1 is not particularly limited.
When the multilayer film 1 is used as a cover material, the thickness _T1 of the multilayer film 1 is preferably 300 μm or less, more preferably 250 μm or less, in order to further improve the sealing properties of the multilayer film 1. more preferred.

When the multi-layer film 1 is used as a bottom material, the thickness _T1 of the multi-layer film 1 is set to: It is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 160 μm or less.

<Other layers>
The multilayer film 1 does not correspond to any of the outer layer 12, the sealant layer 11, the adhesive layer 139, the first resin layer 131, and the second resin layer 132 within a range that does not impair the effects of the present invention. , may comprise other layers.
The other layer is not particularly limited and can be arbitrarily selected according to the purpose.
Moreover, when the multilayer film 1 includes the other layer, the multilayer film 1 may further include an adhesive layer (for example, the adhesive layer 139 or the like) for bonding the other layer to other layers.

The multilayer film of this embodiment is not limited to the one described above, and part of the configuration may be changed, deleted, or added within the scope of the present invention.
For example, in the multilayer film 1 shown in FIG. 1, the first resin layer 131 and the second resin layer 132 are laminated in this order from the sealant layer 11 side toward the outer layer 12 side, but the order of lamination is reversed. may be
That is, a multilayer film according to one embodiment of the present invention includes a sealant layer, an intermediate layer disposed on the sealant layer, and an outer layer disposed on the intermediate layer, and further the intermediate layer is an adhesive layer, a second resin layer disposed on the adhesive layer, a first resin layer disposed on the second resin layer, and the first resin layer from the sealant layer side toward the outer layer side. and an adhesive layer disposed on one resin layer.

The multilayer film of the present embodiment can be used, for example, as both a lid material and a bottom material for constituting a package to be described later, and is particularly suitable for use as a lid material.

<<Method for producing multilayer film>>
The multilayer film of the present embodiment can be produced by, for example, a feed block method in which resins, resin compositions, etc., which are the materials for forming each layer, are melt-extruded using several extruders, or a co-extrusion T-die method such as a multi-manifold method. , an air-cooled or water-cooled co-extrusion inflation method, or the like.

In addition, the multilayer film of the present embodiment is obtained by coating the surface of another layer for constituting the multilayer film with a resin, a resin composition, or the like, which is a material for forming one of the layers, and optionally It can also be produced by forming a laminated structure in the multilayer film by drying under a vacuum, and if necessary, further laminating layers other than these so as to obtain the intended arrangement form.

In the multilayer film of the present embodiment, two or more films for constituting any two or more layers thereof are separately prepared in advance, and these films are laminated using an adhesive by a dry lamination method, extrusion method, or the like. It can also be produced by laminating and laminating by any one of lamination method, hot melt lamination method and wet lamination method, and if necessary, further lamination so that other layers are arranged in the desired configuration. At this time, an adhesive capable of forming the adhesive layer may be used as the adhesive.

In addition, the multilayer film of the present embodiment is obtained by laminating two or more films separately prepared in advance as described above by laminating them by a thermal (heat) lamination method or the like without using an adhesive. If necessary, it can also be produced by further laminating layers other than these so as to obtain a desired arrangement form.

When manufacturing the multilayer film of the present embodiment, two or more methods for forming any layer (film) in the multilayer film described above may be combined.

<< package >>
A package according to one embodiment of the present invention includes the multilayer film according to one embodiment of the present invention described above.
The packaging body of the present embodiment can be produced by using a conventional deep-drawing packaging machine that can be vertically displayed. Such packages (eg, deep-drawn packages) are different from conventional skin packs, but have similar properties and are cheaper to manufacture than skin packs.
The package of the present embodiment is suitable as, for example, a packaging bag or a packaging container for packaging food or the like.

FIG. 2 is a cross-sectional view schematically showing a package according to one embodiment of the invention.
In the drawings after FIG. 2, the same constituent elements as those shown in already explained figures are given the same reference numerals as in the already explained figures, and detailed explanations thereof will be omitted.

The packaging body 10 shown here includes a lid member 1 and a bottom member 2 .
The lid member 1 is made of the multilayer film 1 shown in FIG.
By using the lid member 1, the package 10 can be displayed upright with the contents 9 stored therein.
In addition, in FIG. 2, distinction of each layer in the multilayer film 1 is omitted.

The thickness _T1 of the lid member 1 is the same as the thickness _T1 of the multilayer film 1 described above.

The bottom material 2 is obtained by deep-drawing a film, and usually consists of a transparent multilayer resin film (hereinafter simply referred to as "multilayer film").
A concave portion 2c is formed in the bottom material 2, and one surface (in this specification, may be referred to as a “first surface”) 2a of a region of the bottom material 2 excluding the concave portion 2c, and a lid member The first surface 11a of the (multilayer film) 1 is in close contact with the seal. As a result, a storage portion 10a is formed between the first surface 2a of the bottom member 2 and the first surface 11a of the lid member 1 in the region of the recessed portion 2c of the bottom member 2. As shown in FIG. An object 9 is hermetically sealed in the storage portion 10a.
In FIG. 2, there are some gaps between the container 9 and the lid member 1 and between the container 9 and the bottom member 2 in the storage part 10a of the package 10. , the presence of these gaps is not essential in the package 10 in which the contents 9 are accommodated.

A preferable multilayer film for forming the bottom material 2 has a thickness of 160 μm or less, more preferably 155 μm or less, as described above. When the thickness of the multilayer film is equal to or less than the upper limit value, the effect that the bottom member 2 is brought into close contact with the stored object 9 in the storage portion 10a is enhanced.
On the other hand, the lower limit of the thickness of the multilayer film for forming the bottom material 2 is not particularly limited. However, in terms of increasing the strength of the bottom material 2, the thickness of the multilayer film is preferably 70 μm or more, as described above.
These thicknesses of the multilayer film for forming the base material 2 are the same as the thickness _T2 of the base material 2 .

As an example of the package of this embodiment, the package includes a lid material and a bottom material, the lid material is made of the multilayer film of the above-described embodiment, and the package is the lid material and a deep-drawn package constructed by sealing the bottom material.

In the packaging body of the present embodiment, it is preferable that both the thicknesses of the lid material and the bottom material satisfy the conditions of the preferred numerical ranges described above. For example, as an example of such a package, the thickness of the lid material is 100 μm or more and the thickness of the bottom material is 160 μm or less.

The container 9 can be arbitrarily selected according to the purpose and is not particularly limited, but is preferably food.

Although the mass of the contained item 9 is not particularly limited, it is preferably 60 g or less from the viewpoint that the package 2 is more suitable for standing display.

The package of the present embodiment is not limited to the above-described one, and part of the configuration may be changed, deleted, or added within the scope of the present invention.
For example, the package 10 shown in FIG. 2 uses the multilayer film 1 shown in FIG. 1, but the package of this embodiment uses a multilayer film other than the multilayer film 1 shown in FIG. There may be.

<<How to use the package>>
The package of the present embodiment does not contact the display surface of the display area with the flat surface of the package (more specifically, the exposed surface of the lid or bottom material), but the edge of the package is in contact. The package can be displayed in a standing position with the package upright. At this time, one package may be vertically displayed by itself, or two or more packages may be stacked and displayed vertically.

<<Method for manufacturing package>>
The package of this embodiment can be manufactured by stacking and heat-sealing the lid member and the bottom member so as to form the storage portion.
When manufacturing the package, the contents are stored in the storage portion before the lid member and the bottom member are heat-sealed.

The present invention will be described in more detail below with reference to specific examples. However, the present invention is by no means limited to the examples shown below.

<<Manufacturing multilayer film and package>>
[Example 1]
A multilayer film having the structure shown in FIG. 1 and a package having the structure shown in FIG. 2 were manufactured by the following procedure.

<Production of multilayer film for lid material>
An ethylene-vinyl acetate copolymer resin (“Evaflex EV460” manufactured by Mitsui DuPont Polychemicals, melting point 84° C.) was prepared as a resin constituting the sealant layer.
As the polyester constituting the outer layer, polyethylene terephthalate (“Novapex GM700Z” manufactured by Mitsubishi Chemical Corporation) was prepared.
As the first resin constituting the first resin layer, polyamide ("Ube Nylon 1030B" manufactured by Ube Industries, Ltd.) was prepared.
EVOH (“EVAL J171B” manufactured by Kuraray Co., Ltd.) was prepared as the second resin constituting the second resin layer.
A polyolefin having a polar group ("Modic M555" manufactured by Mitsubishi Chemical Corporation) was prepared as an adhesive resin constituting the first adhesive layer.
A polyolefin having a polar group (“Modic F515A” manufactured by Mitsubishi Chemical Corporation) was prepared as an adhesive resin constituting the second adhesive layer.
Then, the sealant layer, the first adhesive layer, the first resin layer, the second resin layer, the second adhesive layer and the outer layer were co-extruded in this order to produce a multilayer film for lid material.
The resulting multilayer film comprises a sealant layer (thickness T ₁₁ =35 μm), a first adhesive layer (thickness 10 μm), a first resin layer (thickness T ₁₃₁ =15 μm), a second resin layer (thickness T ₁₃₂ = 10 μm), a second adhesive layer (thickness T 12 = 120 μm), a second adhesive layer (thickness T ₁₂ = 120 μm) are laminated in this order in the thickness direction, and the thickness T ₁ is 200 μm. .

<Manufacturing of multilayer film for bottom material>
A multilayer film for a bottom material was manufactured in the same manner as the multilayer film for a lid material, except that the amount of resin used for forming each layer was changed.
The obtained multilayer film had a sealant layer (55 μm), a first adhesive layer (10 μm), a first resin layer (15 μm), a second resin layer (10 μm), a second adhesive layer (10 μm) and an outer layer (50 μm). The layers are laminated in this order in the thickness direction and have a thickness of 150 μm.

<Production of package>
The bottom material multilayer film obtained above was subjected to deep drawing to produce a bottom material. The outer shape of the concave portion in the bottom member, which serves as the storage portion, was cylindrical with a diameter of 100 mm and a height (depth) of 8 mm.
Next, 40 g of sliced ham was placed in the recess in the bottom material obtained above. In this state, the multilayer film for lid material obtained above was used as it was as a lid material, and this lid material and bottom material were overlapped so as to form a storage portion and heat-sealed at 135°C.
As described above, a package containing the sliced ham in the container was manufactured.

[Example 2]
<Production of multilayer film for lid material>
A multilayer film for lid material was produced in the same manner as in Example 1, except that the amount of resin used for forming each layer was changed.
The resulting multilayer film includes a sealant layer (thickness T ₁₁ =9 μm), a first adhesive layer (8 μm), a first resin layer (thickness T ₁₃₁ =15 μm), a second resin layer (thickness T ₁₃₂ =10 μm). ), a second adhesive layer (8 μm) and an outer layer (thickness T ₁₂ =150 μm) are laminated in this order in the thickness direction, and the thickness T ₁ is 200 μm.

<Manufacturing of multilayer film for bottom material>
A bottom material multilayer film was manufactured in the same manner as the lid material multilayer film of Example 1, except that the amount of the resin used for forming each layer was changed.
The obtained multilayer film had a sealant layer (9 μm), a first adhesive layer (8 μm), a first resin layer (15 μm), a second resin layer (10 μm), a second adhesive layer (8 μm) and an outer layer (50 μm). The layers are laminated in this order in the thickness direction and have a thickness of 100 μm.

<Production of package>
A package was produced in the same manner as in Example 1, except that the lid material multilayer film and bottom material multilayer film obtained above were used.

[Example 3]
<Production of multilayer film for lid material>
A multi-layer film for lid material was produced in the same manner as in Example 2.

<Manufacturing of multilayer film for bottom material>
A bottom material multilayer film was manufactured in the same manner as the lid material multilayer film of Example 1, except that the amount of the resin used for forming each layer was changed.
The obtained multilayer film had a sealant layer (7 μm), a first adhesive layer (5 μm), a first resin layer (15 μm), a second resin layer (10 μm), a second adhesive layer (5 μm) and an outer layer (28 μm). The layers are stacked in this order in the thickness direction and have a thickness of 70 μm.

<Production of package>
A package was produced in the same manner as in Example 1, except that the lid material multilayer film and bottom material multilayer film obtained above were used.

[Comparative Example 1]
<Production of multilayer film for cover material and multilayer film for bottom material>
A multilayer film for lid material was produced in the same manner as in Example 1, except that the amount of resin used for forming each layer was changed.
The resulting multilayer film includes a sealant layer (thickness T ₁₁ =65 μm), a first adhesive layer (10 μm), a first resin layer (thickness T ₁₃₁ =15 μm), a second resin layer (thickness T ₁₃₂ =10 μm). ), a second adhesive layer (10 μm), and an outer layer (thickness T ₁₂ =40 μm) are laminated in this order in the thickness direction, and have a thickness of 150 μm.
Furthermore, the same multilayer film was produced as the multilayer film for the bottom material.

In this specification, for the sake of convenience, the thickness of the lid material multilayer film of the comparative example and the thickness of each layer in the film are denoted by the same reference numerals as in the example.

<Production of package>
A package was produced in the same manner as in Example 1, except that the lid material multilayer film and bottom material multilayer film obtained above were used.

[Comparative Example 2]
<Production of multilayer film for lid material>
As the resin constituting the sealant layer, instead of "Evaflex EV460", a metallocene-catalyzed linear low-density polyethylene ("Umerit 1520F" manufactured by Ube Maruzen Polyethylene Co., Ltd., melting point 114 ° C.) is used, and each layer is composed of A multilayer film for lid material was produced in the same manner as in Example 1, except that the amount of the resin used for was changed.
The resulting multilayer film includes a sealant layer (thickness T ₁₁ =25 μm), a first adhesive layer (10 μm), a first resin layer (thickness T ₁₃₁ =15 μm), a second resin layer (thickness T ₁₃₂ =10 μm). ), a second adhesive layer (10 μm) and an outer layer (thickness T ₁₂ =180 μm) are laminated in this order in the thickness direction, and the thickness T ₁ is 250 μm.

<Manufacturing of multilayer film for bottom material>
Example 2 except that metallocene-catalyzed linear low-density polyethylene (“Umerit 1520F” manufactured by Ube Maruzen Polyethylene Co., Ltd., melting point 114° C.) was used as the resin constituting the sealant layer instead of “Evaflex EV460”. A multilayer film for bottom material was produced in the same manner as in .
The obtained multilayer film had a sealant layer (9 μm), a first adhesive layer (8 μm), a first resin layer (15 μm), a second resin layer (10 μm), a second adhesive layer (8 μm) and an outer layer (50 μm). The layers are laminated in this order in the thickness direction and have a thickness of 100 μm.

<Production of package>
A package was produced in the same manner as in Example 1, except that the lid material multilayer film and bottom material multilayer film obtained above were used.

[Comparative Example 3]
<Production of multilayer film for lid material>
As the resin constituting the sealant layer, instead of "Evaflex EV460", linear low-density polyethylene ("Ultzex 2022L" manufactured by Prime Polymer Co., Ltd., melting point 120 ° C.) was used. A multilayer film for lid material was produced in the same manner as in Example 2, except that the amount of resin used was changed.
The resulting multilayer film includes a sealant layer (thickness T ₁₁ =9 μm), a first adhesive layer (8 μm), a first resin layer (thickness T ₁₃₁ =15 μm), a second resin layer (thickness T ₁₃₂ =10 μm). ), a second adhesive layer (8 μm) and an outer layer (thickness T ₁₂ =150 μm) are laminated in this order in the thickness direction, and the thickness T ₁ is 200 μm.

<Manufacturing of multilayer film for bottom material>
In Example 2, except that linear low-density polyethylene ("Urtzex 2022L" manufactured by Prime Polymer Co., Ltd., melting point 120 ° C.) was used as the resin constituting the sealant layer instead of "Evaflex EV460". A multilayer film for a bottom material was produced in the same manner as above.
The obtained multilayer film had a sealant layer (9 μm), a first adhesive layer (8 μm), a first resin layer (15 μm), a second resin layer (10 μm), a second adhesive layer (8 μm) and an outer layer (50 μm). The layers are laminated in this order in the thickness direction and have a thickness of 100 μm.

<Production of package>
A package was produced in the same manner as in Example 1, except that the lid material multilayer film and bottom material multilayer film obtained above were used.

<<Evaluation of package>>
<Evaluation of sealability>
A test piece with a width of 15 mm including the heat-sealed portion was cut from the package obtained above. A part of the heat-sealed portion of the obtained test piece was peeled off so that the heat-sealed surfaces formed an angle of 180 °, and both ends of the peeled surface generated at this time were held by both grips of the tensile tester. attached to the tool. Then, by applying a tensile stress at a rate of 200 mm / min, the heat-sealed portion is further peeled off, and the heat-sealed portion is completely peeled (that is, opened), and the maximum stress during that time is obtained. of the seal strength.
Then, when the measured value of the seal strength is (10N/15mm) or more, the sealability of the package is judged as "A", and when the measured value of the seal strength is less than (10N/15mm) , the sealability of the package was determined as "B". Table 1 shows the results.

<Evaluation of standing displayability>
The edges of the package obtained above are brought into contact with the display surface of the display case, and the package is placed on the display case without contacting the flat surface of the package (the exposed surface of the lid or bottom material) with the display surface. It was confirmed whether or not the package could be displayed in this state after being placed on a stand.
Then, if the package can be displayed in a leaning state, the prop displayability of the package is determined as "A", and if it is not possible to display the package in a leaning state. evaluated the standing displayability of the package as "B". Table 1 shows the results.

As is clear from the above results, in the lid materials and multilayer films for lid materials of Examples 1 to 3, the melting point of the resin contained in the sealant layer was 84°C, and the thickness _T12 of the outer layer containing polyester was 120 to 120°C. It was 150 μm, and both the sealability and the standing displayability of the package were good. The thickness _T2 of the bottom material and the multilayer film for the bottom material in Examples 1 to 3 was 70 to 150 μm, and the thickness _T1 of the lid material and the multilayer film for the lid material was 200 μm.

On the other hand, in the lid material and the multilayer film for lid material of Comparative Example 1, the thickness _T12 of the polyester-containing outer layer was 40 μm, which was too thin, so that the package was inferior in standability.
Contrary to Comparative Example 1, in the lid material and lid material multilayer film of Comparative Example 2, the thickness _T12 of the outer layer containing polyester was 180 μm, which was too thick, and the melting point of the resin contained in the sealant layer was Since the temperature was 114° C., which was too high, the sealability of the package was poor.
In the lid material and lid material multilayer film of Comparative Example 3, the melting point of the resin contained in the sealant layer was 120° C., which was too high, and thus the sealing performance of the package was poor.

INDUSTRIAL APPLICABILITY The present invention is applicable to packaging bodies used for food storage.

1 Multilayer film (lid material)
DESCRIPTION OF SYMBOLS 11... Sealant layer 12... Outer layer 13... Intermediate layer 131... 1st resin layer 132... 2nd resin layer 139... Adhesive layer 10... Package body 2... Bottom Materials T ₁ Thickness of multilayer film (lid material) T ₁₂ Thickness of outer layer T ₂ Thickness of bottom material

Claims (6)

A multilayer film comprising an outer layer containing polyester and a sealant layer containing a resin having a melting point of less than 100°C,
The outer layer has a thickness of 100 to 170 μm,
The ratio of the thickness of the outer layer to the thickness of the multilayer film is 58% or more,
The resin having a melting point of less than 100° C. is one or more selected from the group consisting of ethylene-methacrylic acid copolymers, ethylene-vinyl acetate copolymers and ionomers,
In addition to the resin having a melting point of less than 100° C., the sealant layer further includes, as a resin having a melting point of 100° C. or higher, one or more selected from the group consisting of polypropylene and ethylene-propylene copolymers. When the peelable resin is included, the ratio of the total content of the resin having a melting point of less than 100° C. and the easy peelable resin to the total mass of the sealant layer in the sealant layer is 85% by mass. Above, in the sealant layer, the ratio of the content of the resin having a melting point of less than 100° C. to the total content of the resin having a melting point of less than 100° C. and the easy peeling resin is 60 to 90. % by mass,
When the sealant layer does not contain the easy-peel resin, the ratio of the content of the resin having a melting point of less than 100° C. in the sealant layer to the total mass of the sealant layer is 85% by mass or more. can be,
The multilayer film, wherein the polyester is one or more selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate and glycol-modified polyethylene terephthalate. 2. The multilayer film of claim 1, further comprising an intermediate layer between said outer layer and said sealant layer. 3. The multilayer film according to claim 1 , wherein the multilayer film has a thickness of 180 [ mu]m or more. A package comprising the multilayer film according to any one of claims 1 to 3 . The package comprises a lid material and a bottom material,
The lid material is made of the multilayer film,
5. The package of claim 4 , wherein the package is a deep draw package formed by sealing the lid and bottom material. The package according to claim 5 , wherein the lid member has a thickness of 180 µm or more, and the bottom member has a thickness of 160 µm or less.

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