JP2019151351A - Package - Google Patents

Abstract

To provide a package which has an excellent food hygiene aspect, which can be manufactured by a simple method, and which has both favorable easily-opening property and favorable re-sealability just by pressurized bonding by a hand or fingers.SOLUTION: A package comprises a multilayer film that comprises a surface resin layer (A), an adhesive resin layer (B), a peelable resin layer (C), and a heat seal resin layer (D) which are laminated sequentially, and that is used for one of a lid member and a bottom member of the package, with the heat seal resin layer (D) of the multilayer film being heat-sealed to the other one of the bottom member and the lid member of the package, to be sealed. When the package is opened, in a heat-sealed part of the package, the inter-layer peeling occurs between the adhesive resin layer (B) and the peelable resin layer (C), and both layers are exposed in a resealable state. The adhesive resin layer (B) comprises a resin composition whose main component is aliphatic polyolefin resin in which loss viscoelasticity E'' at the temperature of 25°C measured at the frequency 10 Hz by the dynamic viscoelasticity measurement is equal to or less than 10.0×10Pa.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a package having a multilayer film as a lid or bottom material, and more particularly to a re-sealable package that is suitably used for packaging foods, pharmaceuticals, and the like.

  Conventionally, various packages with resealing function have been used as packaging means for cosmetics and sanitary products that are repeatedly opened and resealed every time they are used, or for food and pharmaceuticals that cannot be consumed once. . This package can prevent oxidative deterioration of the contents remaining after opening, or deterioration due to moisture absorption, drying, etc. For example, a zipper type package in which a plastic zipper is laminated is known. However, although this package can be repeatedly opened and has excellent durability, a dedicated device for attaching an accessory such as a zipper to the package is necessary, and a processing step associated therewith is also necessary. There are problems such as increased manufacturing costs and reduced production efficiency.

  On the other hand, a multilayer film that can give a reseal function to the package itself without attaching an accessory such as a zipper has been developed. For example, Patent Documents 1 and 2 include a surface resin layer, an adhesive resin layer containing a hydrogenated styrene-diene rubber block copolymer and a tackifier, and a heat seal resin layer. There is disclosed a multilayer film that can be exposed in an adhesive state in which an adhesive resin layer can be resealed at a heat seal portion when the multilayer film used as a lid for a package is peeled off.

  Patent Document 3 discloses a heat-sealing packaging material in which an adhesive resin layer (adhesive layer) and a heat seal agent layer are formed in this order on at least one surface of a substrate, and the adhesive resin layer and the above-mentioned A packaging material is disclosed in which the adhesive strength between the heat sealant layers is smaller than the heat seal strength between the heat sealant layer and the layer to be heat sealed.

  Specifically, as an example, on a biaxially stretched polypropylene surface of a laminate film (thickness 50 μm) made of polyester and biaxially stretched polypropylene, 10% by mass of styrene and 90% by mass of a diene hydrocarbon are formed. An adhesive resin layer having a thickness of 25 μm was laminated by extrusion lamination using a random copolymer with a hydrogenated product of a random copolymer, and a solvent-soluble acrylic heat seal lacquer was coated on the adhesive resin layer. The packaging material (lid material) used as the sealing agent layer is exemplified. In the case of a package that is cut out in a circle with a tab and heat-sealed in a polystyrene container, which is the bottom material, if the tab is pinched and pulled, peeling occurs at the interface between the adhesive resin layer and the heat-sealant layer. It is described that when the cover is put on a container and pressure-bonded with a finger or the like, the adhesive resin layer re-adheres to the flange portion and is sealed again.

  Further, it is disclosed that a styrene-based thermoplastic elastomer having specific viscoelastic properties is used as a main component of an adhesive resin layer, and a release resin layer is disposed between the adhesive resin layer and the heat seal resin layer (patent) Reference 4).

  However, in said patent documents 1-4, the styrene-type elastomer is used as a material which comprises an adhesive resin layer. When a styrene elastomer is used, low molecular weight components such as styrene monomers are likely to be eluted, so that the use may be limited from the viewpoint of food hygiene.

JP 2003-175567 A JP 2004-75181 A JP 2005-41539 A JP 2008-200960 A

  The present invention has been made in order to solve the problems of conventional multilayer films, is excellent in food hygiene, has good easy-openability, and has good resealability only by pressure and pressure bonding with hands and fingers. It is an object to provide a package having both properties.

  As a result of intensive studies, the present inventors have used an aliphatic polyolefin resin having specific viscoelastic properties as a main component of the adhesive resin layer, and a release resin between the adhesive resin layer and the heat seal resin layer. It has been found that the above-mentioned problems can be solved by arranging the layers, and the following invention has been completed.

According to the first aspect of the present invention, a multilayer film comprising a surface resin layer (A), an adhesive resin layer (B), a release resin layer (C), and a heat seal resin layer (D) is sequentially laminated. Or it is a package body which is used for one of the bottom materials and heat-sealed the heat seal resin layer (D) of the multilayer film to the bottom material or lid material of the package body to be sealed, and the package body is opened. In the heat sealing part of the packaging body, the adhesive resin layer (B) and the release resin layer (C) are delaminated, and the packaging body is exposed in a state where both layers can be resealed,
The adhesive resin layer (B) is mainly composed of an aliphatic polyolefin resin having a loss viscoelasticity E ″ at 25 ° C. of 10.0 × 10 ⁶ Pa or less measured at a frequency of 10 Hz by dynamic viscoelasticity measurement. It is the package which consists of a resin composition.

  In the first aspect of the present invention, the exposure of the adhesive resin layer (B) in the heat seal part of the packaging body is caused by breakage of the release resin layer (C) and the heat seal resin layer (D) from the multilayer film, and the adhesive resin layer. It is preferable to be carried out by delamination between (B) and the release resin layer (C) and by shifting the fractured release resin layer (C) and heat seal resin layer (D) to the sealed body side.

  In the first invention, the aliphatic polyolefin resin constituting the pressure-sensitive adhesive resin layer (B) is a copolymer containing at least propylene and an aliphatic α-olefin having 4 to 20 carbon atoms as monomers. It is preferable.

  In the first invention, the surface resin layer (A) is at least one heat selected from the group consisting of aliphatic polyolefin resins, amide resins, saponified ethylene-vinyl acetate copolymers, and polyester resins. It is preferable that the main component is a plastic resin.

  In the first invention, the release resin layer (C) is at least one thermoplastic selected from the group consisting of polyester resins, amide resins, cyclic polyolefin resins, and saponified ethylene-vinyl acetate copolymers. It is preferable that the resin is a main component.

  In the first aspect of the present invention, the surface resin layer (A) is composed of two or more layers, and has a layer mainly composed of a saponified ethylene-vinyl acetate copolymer and / or a layer mainly composed of a polyamide-based resin. A multilayer is preferred.

  In the first aspect of the present invention, the total thickness of the release resin layer (C) and the heat seal resin layer (D) is preferably 1 μm or more and 30 μm or less.

In the first aspect of the present invention, the pressure-sensitive adhesive resin layer (B) preferably does not contain a tackifier.
Here, examples of the tackifier include rosin resins, terpene resins, and petroleum resins.

  In the first aspect of the present invention, the heat seal resin layer (D) is preferably composed mainly of an aliphatic polyolefin resin, a polyester resin, or a mixture thereof.

  According to the present invention, it is possible to provide a package that is excellent in food hygiene and has both good easy-openability and good resealability only by pressure and pressure bonding with hands and fingers.

FIG. 1 is a partial cross-sectional view of a package of the present invention using a multilayer film as a lid. FIG. 2 is a partial cross-sectional view of the package body showing a state where a part of the lid member is peeled from the container in the package body shown in FIG. 1. FIG. 3 is a partial cross-sectional view showing a state where the lid and the bottom material are resealed in the package shown in FIG. 1.

Hereinafter, the multilayer film with a reseal function, a lid material, a bottom material, and a package that constitute the package of the present invention will be described in detail.
In the present specification, “configured as a main component” is intended to allow other components to be included within a range that does not impede the action and effect of the resin constituting each layer. Further, this term does not limit the specific content, but it is 50% by mass or more and 100% by mass or less, preferably 85% by mass or more and 100% by mass or less, more preferably 95% by mass of the total constituent components of each layer. It means that it occupies% or more and 100 mass% or less.

<Multilayer film>
The multilayer film constituting the package of the present invention is a multilayer film in which a surface resin layer (A), an adhesive resin layer (B), a release resin layer (C), and a heat seal resin layer (D) are sequentially laminated. An aliphatic polyolefin resin in which the adhesive resin layer (B) has a loss viscoelasticity E ″ at 25 ° C. of 10.0 × 10 ⁶ Pa or less measured at a frequency of 10 Hz by dynamic viscoelasticity measurement. It is a multilayer film which consists of a resin composition which has a main component.

  And this multilayer film has the following function. That is, the multilayer film is used as one of the lid or bottom material of the packaging body, and the heat seal resin layer (D) of the multilayer film is heat sealed at the bottom material of the packaging body that is the sealed body or the heat seal portion of the lid material. Then, when opening the package, the adhesive resin layer (B) and the release resin layer (C) are delaminated in the heat seal part, and the adhesive resin layer (B) is It has a reseal function that is exposed in a resealable state with the release resin layer (C).

(Surface resin layer (A))
First, the surface resin layer (A) of the film will be described. The surface resin layer (A) is a layer composed mainly of a thermoplastic resin, and the delamination strength between the surface resin layer (A) and the adhesive resin layer (B) at the time of peeling is such that the adhesive resin layer ( The layer structure is not particularly limited as long as it is greater than the delamination strength between B) and the release resin layer (C), and may be a single layer or a multilayer.

  The thermoplastic resin used as the main component of the surface resin layer (A) considers the type of resin used as the main component of the adhesive resin layer (B), the release resin layer (C), and the heat seal resin layer (D). It is preferable to select as appropriate. Since the thermoplastic resin has a melt extrusion temperature in the range of approximately 180 ° C. or more and 300 ° C. or less, a thermoplastic resin that can be melt-extruded within this range is preferably used. Specifically, as the thermoplastic resin, aliphatic polyolefin resin (ethylene resin, propylene resin, cyclic polyolefin resin, etc.), amide resin, saponified ethylene-vinyl acetate copolymer, polyester resin, Examples include polycarbonate resins. These thermoplastic resins can be used alone or as a mixed resin composition of two or more, and can form a single layer structure or a multilayer structure.

  In the present invention, in consideration of molding processability, production cost, transparency and the like, the thermoplastic resin includes aliphatic polyolefin resin, amide resin, saponified ethylene-vinyl acetate copolymer, and polyester resin. At least one thermoplastic resin selected from the group consisting of can be preferably used.

  Examples of the ethylene resin include ethylene resins such as very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE); Ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-acrylic acid copolymer Polymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-glycidyl methacrylate copolymer (E-GMA), ethylene-vinyl acetate-glycidyl methacrylate copolymer (E-VA-GMA), ethylene- Maleic anhydride copolymer (E-MA ), Ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), and the like; and further, metal-neutralized ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer Examples thereof include a metal neutralized product of coalescence. These may be used alone or in combination of two or more.

  Examples of the propylene resin include propylene homopolymers, copolymers of propylene and other aliphatic α-olefins such as ethylene and butene, and the copolymers include random copolymers and block copolymers. Any of these can be used. The stereoregularity may be any of an isotactic structure, a syndiotactic structure, an atactic structure, a stereo block structure, and the like. These may be used alone or in combination of two or more.

  Examples of the amide-based resin include, as aliphatic polyamide polymers, ring-opening polymers of cyclic lactams, polycondensates of aminocarboxylic acids, and polycondensates of dicarboxylic acids and diamines. Specifically, a homopolymer of ε-caprolactam referred to as 6 nylon, polyhexamethylene adipamide referred to as 66 nylon, or 6-66 nylon as a copolymer thereof can be used. Moreover, as an aromatic polyamide polymer, a resin containing 70 mol% or more of a polyamide constituent unit composed of xylylenediamine and an α, ω aliphatic dicarboxylic acid having 6 to 12 carbon atoms in the molecular chain, etc. Can be used. Specifically, homopolymers such as polymetaxylylene adipamide, polymetaxylylene pimeramide, polymetaxylylene azelamide, polyparaxylylene azelamide, polyparaxylylene decanamide, metaxylylene / paraxylylene azamide Examples of the copolymer include a amide copolymer, a metaxylylene / paraxylylene pimeramide copolymer, a metaxylylene / paraxylylene azeramide copolymer, and a metaxylylene / paraxylylene sepacamide copolymer. These may be used alone or in combination of two or more.

  The saponified ethylene-vinyl acetate copolymer has an ethylene content of 29% or more, preferably 32% or more, 47 mol% or less, preferably 44 mol% or less, and a saponification degree of 90%. Above, preferably 95% or more is suitably used. By selecting a grade in which the ethylene content and the degree of saponification are in the above ranges, the gas barrier properties and mechanical strength of the film can be improved. These may be used alone or in combination of two or more.

  Examples of the polyester resin include polyethylene terephthalate resin, polypropylene terephthalate resin, polybutylene terephthalate resin, polyethylene isophthalate resin, polyethylene naphthalate resin, polybutylene naphthalate resin, polyethylene terephthalate / isophthalate copolymer resin, 1,4-cyclohexane. Represented by low crystalline or amorphous polyethylene terephthalate resin, polyethylene / neopentyl terephthalate copolymer resin, and polylactic acid-based resin containing 15 to 50 mol% of dimethanol units in all glycol monomer units. Aliphatic polyester resins and the like can be mentioned.

  In addition, a thermoplastic polyester elastomer having a high melting point and high crystallinity aromatic polyester as a hard segment and an amorphous polyester or amorphous polyether as a soft segment may be appropriately mixed with the polyester resin. These elastomers may be used alone or in a suitable mixture of two or more.

  In order to impart functions such as gas barrier properties and pinhole resistance to the multilayer film, the surface resin layer (A) is composed of two or more layers, and the saponified ethylene-vinyl acetate copolymer is the main component. It is preferable to have a multilayer structure having a layer mainly composed of a layer and / or a polyamide-based resin. However, when the surface resin layer (A) has a multilayer structure, the delamination strength between the resin layers constituting the multilayer is the delamination strength between the adhesive resin layer (B) and the release resin layer (C). It is also important to appropriately select and use an adhesive resin that is larger than that. Alternatively, the surface resin layer (A) may have a multilayer structure, and the layer on the adhesive resin layer (B) side may be a layer made of an adhesive resin. Thereby, the delamination strength between the surface resin layer (A) and the adhesive resin layer (B) at the time of peeling of the package is the delamination strength between the adhesive resin layer (B) and the release resin layer (C). It becomes easy to adjust to become larger.

  Here, as the adhesive resin, ethylene-based resins such as linear low density polyethylene (LLDPE), low density polyethylene (LDPE), and ethylene-vinyl acetate copolymer (EVA), propylene homopolymer, and Propylene-based resins such as copolymers of propylene and other α-olefins, monobasic unsaturated fatty acids such as acrylic acid or methacrylic acid, or methyl acrylate, methyl methacrylate, or glycidyl methacrylate A polyolefin-based adhesive resin in which an ester compound of a monobasic unsaturated fatty acid or an anhydride of a dibasic fatty acid such as maleic acid, fumaric acid or itaconic acid is chemically bonded is preferably used. Specific examples of such adhesive resins include trade name “Admer” manufactured by Mitsui Chemicals, trade name “Modic” manufactured by Mitsubishi Chemical Corporation, and the like.

  Other components may be appropriately added to the surface resin layer (A) as long as the gist of the present invention is not impaired. Specific examples include components such as an antifogging agent, an antistatic agent, a heat stabilizer, a nucleating agent, an antioxidant, a lubricant, an antiblocking agent, a release agent, and an ultraviolet absorber. When the surface resin layer (A) has a multilayer structure, it may be added only to a specific layer or may be added to all layers.

(Adhesive resin layer (B))
Next, the adhesive resin layer (B) will be described. The adhesive resin layer (B) is composed mainly of a polyolefin resin having a loss viscoelasticity E ″ at 25 ° C. of 10.0 × 10 ⁶ Pa or less measured at a frequency of 10 Hz by dynamic viscoelasticity measurement. It is important that it is a layer. Here, if the loss viscoelastic modulus E ″ at 25 ° C. is 10.0 × 10 ⁶ Pa or less, the pressure-sensitive pressure applied to the adhesive resin layer (B) and the release resin layer (C) exposed at the time of peeling by hand or finger It is preferable because practical resealability is exhibited only by wearing. The preferable range of the loss viscoelastic modulus E ″ is 10.0 × 10 ⁶ Pa or less, more preferably 5.0 × 10 ⁶ Pa or less, and further preferably 3.0 × 10 ⁶ Pa or less.

The adhesive resin layer (B) is composed mainly of a polyolefin resin having a loss viscoelastic modulus E ″ at 25 ° C. measured at a frequency of 10 Hz by dynamic viscoelasticity measurement of 10.0 × 10 ⁶ Pa or less. The polyolefin-based resin is preferably a polypropylene-based resin. Among them, a random resin containing an aliphatic α-olefin having 4 to 20 carbon atoms in addition to propylene is preferable. It is preferably a copolymer, more preferably a random copolymer containing an aliphatic α-olefin having 4 to 8 carbon atoms, and a random copolymer with an aliphatic α-olefin having 4 carbon atoms. It is particularly preferred. Moreover, as a particularly preferred form, a random copolymer using the above aliphatic α-olein and further ethylene can be preferably used in addition to propylene.

Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-octene, and 1-decene. The propylene-based structural unit of the propylene-based polymer constituting this is 51 to 90 mol%, preferably 60 to 89 mol%, more preferably 62 to 88 mol%, and the structural unit derived from the aliphatic α-olefin is 0 to 90 mol%. 25 mol%, preferably 0 to 24 mol%, more preferably 0 to 23 mol%, particularly preferably 2 to 23 mol%. As the α-olefin, 1-butene is preferably used.
As a specific example of such an adhesive resin, trade name “Tuffmer” manufactured by Mitsui Chemicals, Inc. can be exemplified.

  Other resins and components may be appropriately added to the pressure-sensitive adhesive resin layer (B) as long as the gist of the present invention is not impaired. Specific examples include low crystalline or amorphous aliphatic polyolefin resins, softeners, stabilizers (antioxidants and the like), and the like.

  Also, from the point of view of food hygiene, the adhesive resin layer (B) should not contain tackifying resins such as styrene resins, rosin resins, terpene resins, petroleum oils and fats that may release styrene monomers. Is preferred.

(Release resin layer)
Next, the release resin layer (C) will be described. The release resin layer (C) is a layer composed of a thermoplastic resin as a main component, and the delamination strength between the adhesive resin layer (B) and the release resin layer (C) at the time of peeling is the surface resin layer ( A layer structure that is smaller than the delamination strength between A) and the adhesive resin layer (B) and between the release resin layer (C) and the heat seal resin layer (D) is particularly limited. Instead, it may be a single layer or multiple layers as desired.

  The thermoplastic resin contained as the main component of the release resin layer (C) is melt-extruded at a melt extrusion temperature of about 180 ° C. to 300 ° C. in the same manner as the thermoplastic resin constituting the main component of the surface resin layer (A). Possible thermoplastic resins are preferably used. Specifically, as the thermoplastic resin constituting the release resin layer (C), easy opening with the adhesive resin layer (B) whose main component is the aliphatic polyolefin resin having the predetermined loss elastic modulus, Considering the balance with sealing properties, moldability, transparency, etc., at least one selected from the group consisting of polyester resins, amide resins, cyclic polyolefin resins, and saponified ethylene-vinyl acetate copolymers A thermoplastic resin is mentioned.

  By disposing a release resin layer (C) that is poorly compatible with the adhesive resin layer (B) between the adhesive resin layer (B) and the heat seal resin layer (D), the bottom of the package body to be sealed Without being limited to the resin constituting the heat seal portion of the material or the cover material, it is possible to impart a good initial peel strength and resealability function with the adhesive resin layer (B). In the present invention, the thermoplastic resin constituting the release resin layer (C) is made of a thermoplastic resin having an excellent initial peel strength and resealability from the adhesive resin layer (B) than the resin constituting the D layer. Is preferred.

  In addition, in the release resin layer (C), in order to develop stable resealability between the adhesive resin layer (B) and the release resin layer (C), mixing with an additive that easily bleeds on the surface of the release resin layer (C) It is preferable not to do as much as possible.

(Heat seal resin layer (D))
Next, the heat seal resin layer (D) will be described. When the heat seal resin layer (D) is heat sealed at the heat seal portion of the sealed body, and then the multilayer film is peeled from the sealed body at the heat seal portion, the heat seal resin layer (D) and the heat seal resin layer (D) are heat sealed. There is no particular limitation as long as the layer peel strength between the resin layers (D) is larger than the peel strength between the adhesive resin layer (B) and the release resin layer (C). Depending on necessity, it may be a resin layer having a single layer structure or a resin layer having a multilayer structure.

  In addition, the resin constituting the heat seal portion of the heat seal resin is preferably a polyolefin resin and an aliphatic polyolefin resin with good heat sealability when sealing with a polyolefin resin, and when sealing with a polyester resin. It is preferable to use a polyester resin and a polyester resin having good heat sealability. The heat seal resin layer (D) is preferably composed mainly of an aliphatic polyolefin resin, a polyester resin, or a mixture thereof.

  As the aliphatic polyolefin-based resin, an ethylene-based resin, a propylene-based resin, or a mixture thereof can be used. As the ethylene-based resin, very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), Ethylene resins such as low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE); ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene -Ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-glycidyl methacrylate copolymer (E-GMA), ethylene Vinyl acetate-glycidyl methacrylate copolymer (E-VA-GMA), ethylene-maleic anhydride copolymer (E-MAH), ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), etc. Examples thereof include ethylene copolymers; further, metal-neutralized products of ethylene-acrylic acid copolymers, metal-neutralized products of ethylene-methacrylic acid copolymers, and the like. These may be used alone or in combination of two or more.

  Examples of the propylene-based resin include propylene homopolymers and copolymers of propylene and other α-olefins such as ethylene and butene. As the copolymers, both random copolymers and block copolymers are used. Can be used. The stereoregularity may be any of an isotactic structure, a syndiotactic structure, an atactic structure, a stereo block structure, and the like. These may be used alone or in combination of two or more.

  As the polyester resin, it is desirable to use an amorphous polyester resin that can be heat-sealed even at a low temperature. The amorphous polyester resin here is a polyester resin in which a melting point peak is not observed by DSC. For example, an amorphous polyester layer made of polyethylene terephthalate glycol (PETG) resin can be provided.

  The PETG resin refers to a polyester resin in which 5 mol% or more of 1,4-cyclohexanedimethanol component is contained in 100 mol% of the polyhydric alcohol component. From the viewpoint of increasing the degree of non-crystallinity, it is desirable that 1,4-cyclohexanedimethanol is contained in an amount of 10 mol% or more, preferably 12 mol% or more, more preferably 15 mol% or more. Examples include “SKYPET S2008” and “Easter Copolyester GN001” manufactured by Eastman Chemical Co., Ltd.

  Moreover, the heat seal resin layer (D) makes the delamination strength between the release resin layer (C) larger than the delamination strength between the adhesive resin layer (B) and the release resin layer (C). Therefore, an adhesive resin layer containing an adhesive resin as a main component between the release resin layer (C) and the heat seal resin layer (D) is contained in the heat seal resin layer (D). (E) can be arranged. As adhesive resin, the thing similar to what was demonstrated in the surface resin layer (A) can be used.

  In addition, it is preferable to add a lubricant to the heat-sealable resin layer (D) from the viewpoint of the processing characteristics of the film, and examples of the lubricant include erucic acid amide and stearic alcohol. The addition amount is preferably 50 to 2000 ppm based on the heat seal layer. Similarly, it is preferable to add an antiblocking agent from the viewpoint of the processing characteristics of the film. Examples of the antiblocking agent include natural silica, synthetic silica, alumina, calcium carbonate and the like. The addition amount is preferably 50 to 5000 ppm based on the heat seal layer.

(Layer thickness)
The adhesive resin layer (B) is usually a resin layer having a single layer structure, and the thickness thereof is not particularly limited, but the balance between easy-openability and resealability, moldability, production cost, etc. Therefore, 0.5 μm or more, preferably 5 μm or more, more preferably 10 μm or more and 100 μm or less, preferably 70 μm or less, more preferably 50 μm or less is suitably employed.

  The total thickness of the release resin layer (C) and the heat seal resin layer (D) is not particularly limited, but is 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more, 30 μm or less, preferably 25 μm. In the following, it is more preferable that the thickness is 15 μm or less. Here, if the total thickness is 1 μm or more, it is preferable because the deformation such as pressurization by a heat seal hot plate at the time of heat sealing can prevent problems such as deterioration of the function of each layer, and the thickness is also preferable. If it is 30 μm or less, the release resin layer (C) and the heat seal resin layer (D) can be easily broken when the adhesive resin layer (B) and the release resin layer (C) are peeled off. It is preferable because the layer (B) can be exposed in a resealable state.

  Further, the thickness of the release resin layer (C) is 0.5 μm or more, preferably 2 μm or more, more preferably 3 μm or more and 29.5 μm or less, preferably 20 μm or less, more preferably 10 μm or less. If the thickness of the release resin layer (C) is 0.5 μm or more, the release resin layer (C) is deformed by the heat sealing pressure during heat sealing, and there are few problems such as a decrease in the function as the release resin layer. If the thickness is 29.5 μm or less, the release resin layer (C) can be easily broken at the time of opening even when a resin having high rigidity such as a polyester-based resin is disposed. The layer (C) and the heat seal resin layer (D) are preferred because they do not easily break down such as a layer remaining on the multilayer film side without breaking.

  Further, the thickness of the heat seal resin layer (D) is 0.5 μm or more, preferably 2 μm or more, more preferably 3 μm or more and 29.5 μm or less, preferably 20 μm or less, more preferably 10 μm or less. If the thickness of the heat seal resin layer (D) is 0.5 μm or more, it is possible to maintain a good interlayer adhesion strength with the release resin layer (C), and the heat seal resin layer ( This is preferable because D) is deformed and defects such as deterioration of the function as the heat seal resin layer are reduced. Moreover, if the thickness is 29.5 μm or less, it is easily broken when opened, and the release resin layer (C) and the heat-seal resin layer (D) are not broken and a layer remains on the multilayer film side. It is preferable because it is less likely to occur.

<Method for producing multilayer film>
Next, the manufacturing method of a multilayer film is demonstrated. Although it does not restrict | limit especially as a manufacturing method of a multilayer film, The coextrusion method excellent in protection, productivity, hygiene, etc. of an adhesive resin layer (B) can be used suitably. That is, each resin composition used for the surface resin layer (A), the adhesive resin layer (B), the release resin layer (C), and the heat seal resin layer (D) described above is heated and melted in a separate extruder, After being laminated in the order of (A) / (B) / (C) / (D) in a molten state by a known method such as a multi-manifold method or a feed block method, a multilayer film is formed by a T-die / chill roll method or an inflation method. Can be molded.

  Here, in order to improve printing suitability and laminate suitability, it is preferable to perform a surface treatment on the surface of the outermost layer of the surface resin layer (A) of the obtained multilayer film. Examples of the surface treatment method include corona treatment, plasma treatment, chromic acid treatment, flame treatment, surface oxidation treatment such as hot air treatment ozone / ultraviolet treatment, sand blasting, and the like. Corona treatment is preferably used from the viewpoint of effects, productivity, and manufacturing cost.

(Lamination process)
The multilayer film is formed on the surface resin layer (A) opposite to the surface on which the pressure-sensitive adhesive resin layer (B) is laminated by a known method such as a dry lamination method or an extrusion lamination method. Laminate base materials can be laminated via an adhesive or an adhesive to form a laminate film or laminate sheet. Here, the laminate substrate is not particularly limited, for example, biaxially stretched polypropylene film, biaxially stretched nylon film, biaxially stretched polyethylene terephthalate film, unstretched polypropylene sheet, unstretched polyethylene terephthalate sheet, An aluminum foil, paper, a nonwoven fabric, etc. are mentioned. In the present invention, a dry lamination method is preferably used, and examples of the adhesive used at that time include a polyester-polyurethane adhesive and a polyether-polyurethane adhesive.

<Packaging body>
In the present invention, the film itself or a laminate film or laminate sheet obtained by laminating a film and a laminate base material can be used as a cover material or a bottom material of various packaging bodies, respectively. For example, when a laminate film is used as a lid for a package (container), the package (container) (sealed body) filled with a heat seal resin layer (D) of the lid and contents such as food By overlapping and heat-sealing with the heat-sealing resin layer, a package (container) having airtightness, practical initial peel strength, and resealing function can be obtained. This package (container) is exposed on the peeled surface after opening in a state where the adhesive resin layer (B) can be resealed, and can be resealed only by pressure pressing with a hand or a finger. Moreover, as a bottom material of various packaging bodies (containers), it is possible to obtain a packaging body (container) having a reseal function similarly by performing deep drawing or the like.

(Resealing mechanism of packaging)
Next, the resealing function in the deep drawn package using the multilayer film defined in the present invention as a lid or bottom material will be described. FIG. 1 is a partial cross-sectional view of a deep-drawn package using a multilayer film defined in the present invention as a lid, and FIG. 2 is a diagram illustrating a part of the lid in the deep-drawn package shown in FIG. FIG. 3 is a partial cross-sectional view showing a state in which the lid material and the bottom material are resealed in the deep-drawn package shown in FIG. 2.

  1 to 3, reference numeral 1 is a lid member, reference numeral 2 is a bottom material (sealed body), reference numeral 3 is a surface resin layer of the lid member, reference numeral 4 is an adhesive resin layer of the lid member, and reference numeral 5 is a lid member. , 6 is a heat seal resin layer of the lid material, 7 is a surface resin layer of the bottom material, 8 is a heat seal resin layer of the bottom material, 9 is a heat seal portion, 10 is a tab portion, Reference numeral 11 denotes an exposed portion of the adhesive resin layer 4 at the time of peeling, and reference numeral 12 denotes an exposed portion of the peeling resin layer 5 at the time of peeling.

  As shown in FIG. 1, the packaging body of the present invention is configured such that a cover material 1 is formed by laminating a surface resin layer 3, an adhesive resin layer 4, a release resin layer 5, and a heat seal resin layer 6 in this order. . The heat seal resin layer 6 of the lid 1 is heat-sealed with the heat seal resin layer 8 of the bottom material 2 that is the object to be sealed. That is, the lid member 1 and the bottom member 2 are bonded by the heat seal portion 9 formed by heat sealing.

  When the tab portion 10 provided on the lid member 1 is picked and pulled, as shown in FIG. 2, in the heat seal portion 9, first, the release resin layer 5 and the heat seal resin layer 6 on the tab portion 10 side are separated from the lid material 1. While being broken, peeling is started between the adhesive resin layer 4 and the release resin layer 5 in the lid member 1. When peeling between the adhesive resin layer 4 and the release resin layer 5 reaches the heat seal portion 9 on the side opposite to the tab portion 10 side, the release resin layer 5 and the heat seal resin layer 6 of the lid member 1 are broken. The release resin layer 5 and the heat seal resin layer 6 of the lid material 1 that has been broken move to the bottom material 2 side that is a sheet body, and the exposed portion 11 of the adhesive resin layer 4 and the exposed portion 12 of the release resin layer 5 It is formed.

  In the case of resealing, as shown in FIG. 3, the peeled cover material 1 is covered on the bottom material 2, and the surface resin layer 3 is pressure-bonded by hand or fingers to form the adhesive resin layer 4 of the cover material 1. By overlapping the exposed portion 11 and the exposed portion 12 of the release resin layer 5 of the lid material 1 that has moved to the bottom material 2, the lid material 1 and the bottom material 2 can be resealed.

  The package of the present invention can be used as various containers, and its use is not particularly limited. For example, the package is packaged in units of several pieces such as wet tissue, perspiration paper, fragrance, disposable diaper, etc. It can be used as a container, or can be used as a container in which pharmaceuticals such as cosmetics, sanitary products, ship medicines, emergency adhesive plasters, and throat candy that are opened and used each time are packaged. In particular, it can be suitably used as a package for storing contents that remain susceptible to deterioration such as oxidative deterioration, moisture absorption, and drying after the opening.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. In addition, the various measured value and evaluation about the film displayed in this specification were performed as follows. Here, the flow direction from the extruder of the film is called the vertical direction, and the orthogonal direction is called the horizontal direction.

(1) Loss viscoelastic modulus E ''
Supply the adhesive resin to an extruder (single-screw extruder with a diameter of 50 mm) of an extrusion film manufacturing apparatus of the T die / chill roll method, and extrude under conditions of an extruder set temperature of 190 to 230 ° C. and a T die set temperature of 200 ° C., A 100 μm thick film was sampled. A sample was cut into a length of 4 mm and a width of 60 mm, using a viscoelastic spectrometer DVA-200 (manufactured by IT Measurement Co., Ltd.) under conditions of vibration frequency 10 Hz, strain 0.1%, heating rate 3 ° C./min, and chuck 25 mm. The transverse direction was measured from −100 ° C., and the loss viscoelastic modulus E ″ at 25 ° C. was determined from the obtained data.

(2) Initial peeling strength The bottom material of the obtained deep-drawn package and the heat seal part of the lid were cut into strips having a width of 15 mm and used as test pieces. The test piece was measured using a universal testing machine (manufactured by Intesco) under the conditions of a temperature of 23 ° C., a tensile speed of 200 mm / min, and a tensile angle of 180 degrees, and the adhesive resin layer (B) and the release resin layer (C) The delamination strength (gf / 15 mm width) was defined as the initial peel strength. In addition, the following standards are also shown.
A: When the initial peel strength is 300 gf / 15 mm width or more and less than 1000 gf / 15 mm,
B: When the initial peel strength is less than 300 gf / 15 mm width or 1000 gf / 15 mm or more,

(3) Reseal peel strength The bottom material of the obtained deep-drawn package and the heat seal part of the lid were cut into strips with a width of 15 mm to form test pieces. The heat seal part is opened, and the part peeled between the adhesive resin layer (B) and the release resin layer (C) is pressure-pressed with a finger and resealed five times. Then, using a universal testing machine (manufactured by Intesco), the peel strength (gf / 15 mm width) measured under the conditions of a temperature of 23 ° C., a tensile speed of 200 mm / min, and a tensile angle of 180 degrees was defined as the resealing peel strength. In addition, the following standards are also shown.
A: When the reseal peel strength is 50 gf / 15 mm width or more, when it is less than 1000 gf / 15 mm,
B: When the reseal peel strength is less than 50 gf / 15 mm width or 1000 gf / 15 mm or more,

Example 1
[Cover material]
The surface resin layer (A) has a three-layer structure using the following three types of resins.
A1: Saponified ethylene-vinyl acetate copolymer (manufactured by Kuraray Co., Ltd., trade name “Eval E105”, hereinafter abbreviated as “EVOH”),
A2: 6-66 nylon resin (manufactured by DSM Japan Engineering Plastics, trade name “Novamid 2030”, hereinafter abbreviated as “6-66Ny”),
A3: Polyolefin-based adhesive resin (manufactured by Mitsui Chemicals, trade name “Admer NF558”, hereinafter abbreviated as “AD1”),

For the adhesive resin layer (B), a polypropylene copolymer resin (Tafmer PN3560 manufactured by Mitsui Chemicals, copolymerization ratio (weight ratio) propylene: ethylene: butene = 75: 5: 20 is abbreviated as “TPP1” hereinafter) is used. Configured.
The release resin layer (C) was composed of an amorphous polyamide resin (manufactured by DSM Japan Engineering Plastics, trade name “Novamid X21”).
The heat-seal resin layer (D) is composed of random polyethylene adhesive resin (Admitor PF508 manufactured by Mitsui Chemicals, Inc., hereinafter abbreviated as “AD2”) manufactured using a metallocene catalyst, 500 ppm of erucamide as a lubricant, A resin composition in which 1000 ppm of natural silica was added and mixed as a blocking agent was used.

  (A) Extruder for layer (single screw extruder of 50 mm in diameter for all three layers), (B) Extruder for layer (single screw extruder of 50 mm in diameter), (C) Extruder for layer (caliber) 50 mm single-screw extruder), (D) T-die / chill roll co-extrusion multi-layer film production apparatus having a layer extruder (single-screw extruder with a diameter of 50 mm) is supplied to each extruder and set for extrusion. Co-extruded under the conditions of a temperature of 190 to 230 ° C. and a T die set temperature of 235 ° C., and the average of each layer in a six-layer configuration of (A1) / (A2) / (A3) / (B) / (C) / (D) A multilayer film (X1) having a thickness of 10 μm / 20 μm / 10 μm / 20 μm / 5 μm / 5 μm and a total thickness of 70 μm was obtained.

Next, a biaxially stretched polyethylene terephthalate film (manufactured by Unitika Ltd., trade name “Emblet PET”, thickness 16 μm) is applied to the outermost layer side of the surface resin layer (A) of the obtained multilayer film (X1) by a dry lamination method. By bonding, a laminate film (X1LF) having a total thickness of 86 μm was obtained and used as a cover material of the package.
In addition, as an adhesive for dry lamination, a two-component curable adhesive (manufactured by Dainippon Ink Co., Ltd., trade name “Dick Dry LX-75A”, as a curing agent, Dainippon Ink Co., Ltd., trade name “Dick Dry KW” −40 ”was used.

[Bottom material]
From the outermost layer side, EVOH, 6-66Ny, AD1, linear low-density polyethylene resin (manufactured by Nippon Polyethylene Co., Ltd., trade name “NOVATEC LL UF240”, hereinafter abbreviated as “LLDPE”) is 1000 ppm of erucic acid amide as a lubricant. In addition, a resin composition (heat seal resin layer) in which 2000 ppm of natural silica was added and mixed as an antiblocking agent was laminated in this order, and each layer had an average thickness of 10 μm / 20 μm / 10 μm / 30 μm and a total thickness of 70 μm. A film (Y1) was obtained by a coextrusion method. An unstretched polyethylene terephthalate sheet having a total thickness of 250 μm (trade name “NOVA CLEAR”, manufactured by Mitsubishi Chemical Corporation) is bonded to the outermost layer side (EVOH surface) of the multilayer film (Y1) by a dry lamination method, and the total thickness is 320 μm. Laminate sheet (Y1LS) was obtained and used as the bottom material of the package. In addition, the grade similar to the case where a laminate film (X1LF) is produced was used as an adhesive for dry lamination.

[Deep-drawn packaging]
Using a deep-drawing packaging machine (manufactured by Mulchback Co., Ltd., model number: R-530), the bottom material is deep-drawn into a rectangular container having a length of 130 mm, a width of 170 mm, and a flange width of 6 mm. In the heat seal part, the above-mentioned cover material (X1LF) is applied to the flange portion provided on the deeply drawn bottom material under the conditions of a heat seal temperature of 180 ° C., a seal time of 2 seconds, and a seal pressure of 4 kg / cm ² . A deep drawn package was produced by heat sealing. The results of evaluation using this deep-drawn package are shown in Table 1 below.

(Example 2)
[Cover material]
For the adhesive resin layer (B), a polypropylene copolymer resin (Tafmer PN2060 manufactured by Mitsui Chemicals, copolymerization ratio (weight ratio) propylene: ethylene: butene = 87: 7: 6 or less is abbreviated as “TPP2”)). The release resin layer (C) is a cycloolefin copolymer resin (trade name “TOPAS 6013F-04” manufactured by Polyplastics Co., Ltd., glass transition temperature (Tg): 138 ° C., hereinafter abbreviated as “COC”. ) Was used to obtain a laminate film (X2LF) in the same manner as in Example 1, except that it was used as a lid for the package.

[Bottom material]
As in Example 1, a laminate sheet (Y1LS) having a total thickness of 320 μm was used as the bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

(Example 3)
[Cover material]
The adhesive resin layer (B) is composed of a polypropylene copolymer resin “TPP2”, and the heat seal resin layer (D) is a random polyethylene adhesive resin manufactured using a metallocene catalyst (Modick P512V manufactured by Mitsubishi Chemical Corporation) A laminate film (same as “AD3”) was used in the same manner as in Example 1 except that the resin composition was mixed with 500 ppm of erucamide as a lubricant and 1000 ppm of natural silica as an antiblocking agent. X3LF) was obtained and used for the lid of the package.

[Bottom material]
From the outermost layer side, EVOH, 6-66Ny, AD4 (Modic P555 manufactured by Mitsubishi Chemical Corporation), polypropylene resin (Novatech PP EG7FTB manufactured by Nippon Polypro Co., Ltd.), 1000 ppm of erucic acid amide as a lubricant, and 2000 ppm of natural silica as an antiblocking agent are added. The mixed resin compositions (heat seal resin layers) are laminated in this order, and a multilayer film (Y1) having an average thickness of each layer of 10 μm / 20 μm / 10 μm / 30 μm and a total thickness of 70 μm is obtained by a coextrusion method. It was. An unstretched polyethylene terephthalate sheet having a total thickness of 250 μm (trade name “NOVA CLEAR”, manufactured by Mitsubishi Chemical Corporation) is bonded to the outermost layer side (EVOH surface) of the multilayer film (Y1) by a dry lamination method, and the total thickness is 320 μm. Laminate sheet (Y2LS) was obtained and used as the bottom material of the package. In addition, the grade similar to the case where a laminate film (X1LF) is produced was used as an adhesive for dry lamination.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Example 4
The release resin layer (C) is composed of the COC used in Example 2, the heat seal resin layer (D) is AD3 used in Example 3, 500 ppm of erucamide as a lubricant, and an antiblocking agent. A laminate film (X4LF) was obtained in the same manner as in Example 1 except that a resin composition in which 1000 ppm of natural silica was added and mixed was used.

[Bottom material]
Similar to Example 3, a laminate sheet (Y2LS) having a total thickness of 320 μm was used as the bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

(Example 5)
The release resin layer (C) is composed of polyethylene terephthalate resin (“RamaPET N1” manufactured by Indrama Co., hereinafter referred to as “PET”), and the heat seal resin layer (D) is formed of PETG (Eastman Chemical Co., Ltd.). A laminate film (X5LF) was prepared in the same manner as in Example 1 except that the resin composition was prepared by adding 500 ppm of erucic acid amide as a lubricant and 1000 ppm of natural silica as an antiblocking agent to “Easter Copolyester GN001” manufactured by And used as a lid for the package.

[Bottom material]
An unstretched polyethylene terephthalate sheet (manufactured by Mitsubishi Chemical Corporation, trade name “Novaclear”) (Y3LS) having a total thickness of 250 μm was used.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

(Example 6)
The adhesive resin layer (B) is configured using TPP2 used in Example 2, and the release resin layer (C) is configured using PETG ("Easter Copolyester GN001" manufactured by Eastman Chemical Co., Ltd.). Except that the layer (D) was composed of PETG used in Example 5 and a resin composition in which 500 ppm of erucamide was added as a lubricant and 1000 ppm of natural silica was added as an antiblocking agent, the same as in Example 1. A laminate film (X6LF) was obtained and used as a lid for the package.

[Bottom material]
An unstretched polyethylene terephthalate sheet (manufactured by Mitsubishi Chemical Corporation, trade name “Novaclear”) (Y3LS) having a total thickness of 250 μm was used.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

(Comparative Example 1)
[Cover material]
A laminate film (X7LF) was obtained in the same manner as in Example 1 except that the adhesive resin layer (B) was constituted by using a polypropylene resin (Novatech PP FB3HAT manufactured by Nippon Polypro Co., Ltd.), and used as a lid for the package. did.

[Bottom material]
As in Example 1, a laminate sheet (Y1LS) having a total thickness of 320 μm was used as the bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

(Comparative Example 2)
[Cover material]
In Example 4, a laminate film (X8LF) was obtained in the same manner as in Example 4 except that the adhesive resin layer (B) was formed using a polypropylene resin (Novatech PP FB3HAT manufactured by Nippon Polypro Co., Ltd.). Used as a lid.

[Bottom material]
As in Example 4, a laminate sheet (Y2LS) having a total thickness of 320 μm was used as the bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

(Comparative Example 3)
[Cover material]
In Example 6, a laminate film (X9LF) was obtained in the same manner as in Example 6 except that the adhesive resin layer (B) was configured using a polypropylene resin (Novatech PP FB3HAT manufactured by Nippon Polypro Co., Ltd.). Used as a lid.

[Bottom material]
Example 6 and an unstretched polyethylene terephthalate sheet (manufactured by Mitsubishi Chemical Corporation, trade name “Novaclear”) (Y3LS) having a total thickness of 250 μm were used.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

From Table 1, it was confirmed that the package of the present invention (deep-drawn package) had no problems in all the properties of the initial peel strength and the reseal peel strength, and was excellent in practicality (Examples 1 to 3). 6).
In contrast, in the case where a polypropylene resin having a loss viscoelasticity of 320 × 10 ⁶ at 25 ° C. was used for the adhesive resin layer, both the initial peel strength and the repeel strength were weak or did not develop.

DESCRIPTION OF SYMBOLS 1 Cover material 2 Bottom material 3 Cover resin surface resin layer 4 Cover material adhesive resin layer 5 Cover material peeling resin layer 6 Cover material heat seal resin layer 7 Bottom material surface resin layer 8 Bottom material heat seal resin layer DESCRIPTION OF SYMBOLS 9 Heat seal part 10 Tab part of cover material 11 Exposed part of adhesive resin layer at the time of peeling 12 Exposed part of heat seal resin layer at the time of peeling

Claims (9)

A multilayer film in which a surface resin layer (A), an adhesive resin layer (B), a release resin layer (C), and a heat seal resin layer (D) are sequentially laminated is used as one of the lid or bottom material of the package. , A heat-sealing resin layer (D) of the multilayer film heat-sealed to the bottom material or lid material of the package body to be sealed, and when the package body is opened, In the heat seal part, the adhesive resin layer (B) and the release resin layer (C) are delaminated, and the package is exposed in a state where both layers can be resealed,
The adhesive resin layer (B) is mainly composed of an aliphatic polyolefin resin having a loss viscoelasticity E ″ at 25 ° C. of 10.0 × 10 ⁶ Pa or less measured at a frequency of 10 Hz by dynamic viscoelasticity measurement. A package comprising a resin composition.   The exposure of the pressure-sensitive adhesive resin layer (B) in the heat-sealed portion of the package is a breakage of the release resin layer (C) and the heat-seal resin layer (D) from the multilayer film, and the pressure-sensitive adhesive resin layer (B) and the release resin layer. The package according to claim 1, which is formed by delamination with (C) and transfer of the fractured release resin layer (C) and heat seal resin layer (D) to the sealed body side.   The aliphatic polyolefin resin constituting the adhesive resin layer (B) is a copolymer containing at least propylene and an aliphatic α-olefin having 4 to 20 carbon atoms as monomers. The package described.   The surface resin layer (A) is composed mainly of at least one thermoplastic resin selected from the group consisting of aliphatic polyolefin resins, amide resins, saponified ethylene-vinyl acetate copolymers, and polyester resins. The package according to any one of claims 1 to 3.   The release resin layer (C) is composed mainly of at least one thermoplastic resin selected from the group consisting of polyester resins, amide resins, cyclic polyolefin resins and saponified ethylene-vinyl acetate copolymers. The package according to any one of claims 1 to 4.   The surface resin layer (A) is composed of two or more layers, and is a multilayer having a layer mainly composed of an ethylene-vinyl acetate copolymer saponified product and / or a layer mainly composed of a polyamide-based resin. The package of any one of -5.   The package according to any one of claims 1 to 6, wherein the total thickness of the release resin layer (C) and the heat seal resin layer (D) is 1 µm or more and 30 µm or less.   The package according to any one of claims 1 to 7, wherein the adhesive resin layer (B) does not contain a tackifier.   The package according to any one of claims 1 to 8, wherein the heat seal resin layer (D) comprises an aliphatic polyolefin resin, a polyester resin, or a mixture thereof as a main component.

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