JP2016005875A - Multilayer film and package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer film and package that have a good pinhole resistance.SOLUTION: Provided is a multilayer film formed by laminating an outer layer, a first resin layer, an oxygen barrier layer, a second resin layer, a core layer and a seal layer in this order, and in which, characterized, the first resin layer is formed by laminating more than one first repeating laminate unit composed of a first base resin layer and a first adhesive layer, the second resin layer is formed by laminating more than one second repeating laminate unit composed of a second base resin layer and a second adhesive layer, and the core layer is composed of a resin composition comprising a biomass-derived polyolefin obtained by polymerizing a monomer containing biomass-derived ethylene.

Description

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

 In a packaging bag and packaging container for packaging foods and pharmaceuticals, a composite multilayer film is often used in order to satisfy various required performances. In addition, the packaging bag here is a bag-shaped bag in which the side surface of a folded or stacked multilayer film is heat-sealed. In addition, the packaging container here is a container-like container obtained by heat-sealing a bottom material obtained by forming a multilayer film into a shape suitable for the contents by vacuum forming or pressure forming and a lid material which is an unformed film. .

 A multilayer film used for a packaging body such as a packaging bag or a packaging container is required to have impact resistance and pinhole resistance. Pinhole resistance is necessary to prevent pinholes from being generated in the package due to external stress applied to the package due to vibration or dropping during the distribution process. Furthermore, when a package is used as an inner bag of a back-in box that is often filled with a liquid material such as a liquid, or the contents having an irregular shape or a sharp portion are packaged with the package. In many cases, the package is required to have higher pinhole resistance than usual. As the multi-layer film having pinhole resistance, various stretched films or multi-layer films containing a polyamide-based resin are preferably used (for example, see Patent Document 1).

 Moreover, the impact resistance and the pinhole resistance required in the package differ depending on the contents to be packaged. For this reason, some multilayer films used for packaging for packaging heavy objects and the like have a thickness range belonging to the sheet classification according to JIS classification.

 In recent years, in order to reduce the environmental load, it is desired to make the thickness of the multilayer film used for the package thinner than the thickness of the conventional multilayer film. Therefore, many attempts to reduce the thickness of the multilayer film by changing the configuration of the multilayer film have been proposed (for example, see Patent Document 2).

 Furthermore, in recent years, in order to reduce the environmental burden, a part of the raw material for the resin film may be replaced with a resin mainly composed of biomass-derived components (hereinafter referred to as “biomass-derived resin”) from a resin derived from petroleum. It has been studied (Patent Document 1). The biomass-derived resin is expected to have the same physical properties as the conventional petroleum-derived resin without any change in chemical structure.

JP 2005-289399 A JP 2008-80509 A JP 2009-155516 A

 However, there is a limit to reducing the thickness of the multilayer film while maintaining the same performance as that obtained with the multilayer film having the conventional thickness.

An object of the present invention is to provide a multilayer film and a package having good pinhole resistance.

 Such an object is achieved by the present invention described in the following (1) to (11).

(1) A multilayer film in which an outer layer, a first resin layer, an oxygen barrier layer, a second resin layer, a core layer, and a seal layer are laminated in this order, wherein the first resin layer is A plurality of first repetitive laminated portions composed of a first base resin layer and a first adhesive layer are laminated, and the second resin layer is a second base composed of a second base resin layer and a second adhesive layer. A multilayer film comprising a resin composition comprising a biomass-derived polyolefin obtained by polymerizing a monomer containing biomass-derived ethylene, wherein a plurality of repeated lamination portions are laminated.
(2) The multilayer film according to (1), wherein the number of laminations of the first repeated lamination part and the number of laminations of the second repetition lamination part are the same number of laminations.
(3) The multilayer film according to the above (1) or (2), wherein the number of laminations of the first repeated lamination part is 2 parts or more and 20 parts or less.
(4) The multilayer film according to any one of the above (1) to (3), wherein the number of laminations of the second repeated lamination part is 2 parts or more and 20 parts or less.
(5) The multilayer film as described in any one of (1) to (4) above, wherein the thickness of each part of the first repeated laminated part is 0.5 μm or more and 40 μm or less.
(6) The multilayer film according to any one of (1) to (5), wherein the thickness of each part of the second repeated laminated part is 0.5 μm or more and 40 μm or less.
(7) The multilayer film according to any one of (1) to (6), wherein the first base resin and the second base resin are the same resin.
(8) The first base resin according to any one of (1) to (7), wherein the first base resin is one or more resins selected from a polyamide resin, a polyethylene resin, a polypropylene resin, and a polyester resin. Multilayer film.
(9) A package comprising the multilayer film according to any one of (1) to (8) above.

 ADVANTAGE OF THE INVENTION According to this invention, the multilayer film and package which have favorable pinhole resistance can be provided.

It is sectional drawing of the multilayer film which concerns on 1st Embodiment of this invention. It is sectional drawing of the multilayer film which concerns on 2nd Embodiment of this invention. It is sectional drawing of the multilayer film which concerns on 3rd Embodiment of this invention. It is sectional drawing of a package provided with the multilayer film of this invention.

 The present invention will be described in detail based on the following preferred embodiments.

(First embodiment)
FIG. 1 is a cross-sectional view illustrating an example of the multilayer film 100 of the first embodiment.

As shown in FIG. 1, the multilayer film 100 according to the first embodiment of the present invention includes an outer layer 1,
The adhesive layer 2, the first resin layer 3, the oxygen barrier layer 4, the second resin layer 5, the adhesive layer 6, the core layer 7, and the seal layer 8 are arranged in this order.

As for the 1st resin layer 3, the 1st repeating lamination | stacking part 31 is laminated | stacked 4 parts. The first repeated lamination part 31 includes a first base resin layer 311 and a first adhesive layer 312.

  In addition, the second resin layer 5 is formed by laminating 4 parts of the second repeated lamination part 51. The second repeated laminated portion 51 includes a second base resin layer 511 and a second adhesive layer 512.

  Hereinafter, each configuration of the multilayer film 100 will be described in detail.

<Outer layer>
Examples of the material of the outer layer 1 include a polypropylene resin, a polyester resin, a polyamide resin, and an ethylene-vinyl alcohol copolymer (hereinafter referred to as “EVOH resin”). Specifically, when heat sterilization is performed on a package after packaging contents such as food, beverages or industrial parts, the outer layer 1 is exposed to hot water and high-temperature steam. Therefore, it is preferable to use a polypropylene resin, a polyamide resin, or a polyester resin having a high melting point such as polyhexamethylene terephthalate resin having a high heat resistance as the material of the outer layer 1.

 For example, a crystalline polypropylene resin or the like is used as the polypropylene resin of the material of the outer layer 1. Specifically, as a crystalline polypropylene resin, at least one of crystalline propylene homopolymer, crystalline propylene-ethylene random copolymer, crystalline propylene-α-olefin random copolymer, ethylene and α-olefin and propylene A crystalline block copolymer is used. As said alpha olefin, C4-C10 alpha olefins, such as 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, are used. These α-olefins may be copolymerized at an arbitrary ratio.

 As the polyester resin of the material of the outer layer 1, for example, a divalent acid such as terephthalic acid as an acid component, or a derivative thereof having an ester forming ability, a glycol having 2 to 10 carbon atoms as a glycol component, and other 2 A saturated polyester resin or the like obtained using a hydric alcohol or a derivative thereof having ester-forming ability is used. Specifically, a polyalkylene terephthalate resin such as a polyethylene terephthalate resin, a polytrimethylene terephthalate resin, a polytetramethylene terephthalate resin, or a polyhexamethylene terephthalate resin is used as the saturated polyester resin. By using these polyester resins, at least one of the appearance and texture of the package can be improved.

 Further, the polyester resin may be copolymerized with other components. As the components to be copolymerized, known acid components, alcohol components, phenol components, derivatives thereof having an ester forming ability, polyalkylene glycol components, and the like are used.

 As an acid component to be copolymerized, for example, a divalent or higher valent aromatic carboxylic acid having 8 to 22 carbon atoms, a divalent or higher valent aliphatic carbon carboxylic acid having 4 to 12 carbon atoms, a divalent or higher valent fatty acid having 8 to 15 carbon atoms. Cyclic carboxylic acids and derivatives thereof having ester forming ability are used. Specifically, examples of the acid component to be copolymerized include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, bis (p-carbodiphenyl) methaneanthracene dicarboxylic acid, 4,4′-diphenylcarboxylic acid, 1,2-bis ( Phenoxy) ethane-4,4′-dicarboxylic acid, 5-sodium sulfoisophthalic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, maleic acid, trimesic acid, trimellitic acid, pyromellitic acid, 1,3- Cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and derivatives thereof having ester forming ability are used. These acid components can be used alone or in combination of two or more.

 Examples of the alcohol component and phenol component to be copolymerized include, for example, a dihydric or higher aliphatic alcohol having 2 to 15 carbon atoms, a divalent or higher alicyclic alcohol having 6 to 20 carbon atoms, and a divalent or higher valence of 6 to 40 carbon atoms. Aromatic alcohols, dihydric or higher phenols, and derivatives thereof having ester forming ability are used. Specifically, as an alcohol component and a phenol component to be copolymerized, ethylene glycol, propanediol, butanediol, hexanediol, decanediol, neopentylglycol, cyclohexanedimethanol, cyclohexanediol, 2,2′-bis (4-hydroxy) Phenyl) propane, 2,2′-bis (4-hydroxycyclohexyl) propane, hydroquinone, glycerin, pentaerythritol and the like, and derivatives thereof having ester forming ability are used.

 Examples of the polyalkylene glycol component to be copolymerized include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, random or block copolymers thereof, alkylene glycols of bisphenol compounds (polyethylene glycol, polypropylene glycol, polytetramethylene glycol, these Modified polyoxyalkylene glycols such as adducts (such as random or block copolymers) are used.

 Examples of the polyamide resin as the material of the outer layer 1 include polycapramide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid (nylon-9), and polyundecanamide (nylon). -11), polylauryl lactam (nylon-12), polyethylenediamine adipamide (nylon-2,6), polytetramethylene adipamide (nylon-4,6), polyhexamethylene adipamide (nylon-6) , 6), polyhexamethylene sebamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12), polyoctamethylene adipamide (nylon-8,6), polydecamethylene adipa Mido (nylon-10,8), a copolymer resin caprolactam / lauryl lactam copolymer (nylon -6/12), caprolactam / ω-aminononanoic acid copolymer (nylon-6 / 9), caprolactam / hexamethylene diammonium adipate copolymer (nylon-6 / 6,6), lauryl lactam / hexamethylene diammonium Adipate copolymer (nylon-12 / 6,6), ethylenediamine adipamide / hexamethylenediammonium adipate copolymer (nylon-2,6 / 6,6), caprolactam / hexamethylenediammonium adipate / hexamethylenedi Ammonium sebacate copolymer (nylon-6 / 6,6 / 6,12), ethyleneammonium adipate / hexamethylenediammonium adipate / hexamethylenediammonium sebacate copolymer (nylon-6 / 6,6 / 6, 10) etc. Polyamide, a polymer obtained by polymerizing at least one of terephthalic acid and isophthalic acid and hexamethylenediamine, specifically, a polymer of hexamethylenediamine-isophthalic acid, a polymer of hexamethylenediamine-terephthalic acid Amorphous polyamide resin such as a copolymer of hexamethylenediamine-terephthalic acid-hexamethylenediamine-isophthalic acid is used. These resins can be used alone or in combination of two or more.

 The ethylene copolymerization ratio of the EVOH resin used for the outer layer 1 is not particularly limited, but is preferably 24 mol% or more and 44 mol% or less. An EVOH resin having an ethylene copolymerization ratio of 24 mol% or more has good processability of the multilayer film 100 into a container shape, and can suppress a decrease in oxygen barrier properties due to the influence of heated water or steam. An EVOH resin having an ethylene copolymerization ratio of 44 mol% or less has good oxygen barrier properties under dry conditions, and the contents are hardly deteriorated.

 The thickness of the outer layer 1 is not particularly limited, but is preferably 3 μm or more and 100 μm or less, more preferably 5 μm or more and 85 μm or less, and further preferably 7 μm or more and 70 μm or less. When the thickness of the outer layer 1 is within the above range, the multilayer film 100 having a good appearance can be obtained at a relatively low cost.

  Further, when the package after packaging the contents is subjected to low-temperature boil treatment, for example, heat sterilization treatment of about 60 ° C. or more and 95 ° C. or less, as the material of the outer layer 1, as in the above, a high heat resistance polypropylene system It is preferable to use a resin, a polyamide resin, a polyester resin having a high melting point, or the like.

 In addition, if the package after the contents are packaged is not heat sterilized, it is a polyester resin with good gloss and rigidity to improve at least one of the appearance of the package and the texture when used. It is preferable to use EVOH resin having good label suitability and rigidity. Label suitability means that when a label with a product name is affixed to the bottom of the bottom material, this label can be applied following a curved surface, and will peel off even after a long time has elapsed since application. Refers to difficult characteristics.

<Adhesive layer 2>
The adhesive layer 2 includes an adhesive strength between the outer layer 1 and the first resin layer 3 (a plurality of first repeated laminated portions 31), waist strength of the multilayer film 100, pinhole resistance, flexibility, moldability, and the like. To improve.

  As the material of the adhesive layer 2, a known adhesive resin, for example, an adhesive polyolefin resin or the like is used. Specifically, as a material for the adhesive layer 2, for example, an ethylene-methacrylate-glycidyl acrylate terpolymer or a monobasic unsaturated fatty acid, a dibasic unsaturated fatty acid, or an anhydride thereof is added to various polyolefins. Grafted ones (maleic acid grafted ethylene-vinyl acetate copolymer, maleic acid grafted ethylene-α-olefin copolymer, etc.) are used. As the monobasic unsaturated fatty acid, acrylic acid, methacrylic acid or the like is used. As the dibasic unsaturated fatty acid, maleic acid, fumaric acid, itaconic acid or the like is used.

  Although the thickness of the contact bonding layer 2 is not specifically limited, It is preferable that they are 2 micrometers or more and 50 micrometers or less, and it is more preferable that they are 3 micrometers or more and 40 micrometers or less. When the thickness of the adhesive layer 2 is within the above range, the multilayer film 100 imparted with good adhesive strength can be obtained at a relatively low cost.

<First resin layer 3>
In the multilayer film 100 of the first embodiment, the first resin layer 3 is formed by laminating three parts of the first repeated laminated part 31, and each first repeated laminated part 31 includes the first base resin layer 311 and the first adhesive. It is composed of layer 312. Thereby, pinhole resistance can be improved.

  The number of laminated layers of the first repeated laminated portion 31 is not particularly limited as long as it is plural or more, but is preferably 2 parts or more and 20 parts or less, more preferably 3 parts or more and 15 parts or less, Most preferably, it is 4 parts or more and 10 parts or less. Thereby, it is possible to achieve a balance between thinning of the multilayer film and pinhole resistance. Furthermore, the appearance of the multilayer film 100 is also excellent.

 The thickness of each layer of the first base resin layer 311 is not particularly limited, but is preferably 0.05 μm or more and 20 μm or less, more preferably 0.1 μm or more and 19 μm or less, 0.2 μm or more, More preferably, it is 18 μm or less. When the thickness of each layer of the first base resin layer 311 is within the above range, the multilayer film 100 has a good appearance and good pinhole resistance, and is thinner than the conventional multilayer film. be able to.

 As a material of the first base layer 311, for example, a thermoplastic resin such as a polyamide resin, a polyethylene resin, a polypropylene resin, a polyester resin, a polycarbonate resin, or a polystyrene resin is used. Among these, one or more resins selected from polyamide resins, polyethylene resins, polypropylene resins, and polyester resins are preferable. Thereby, pinhole resistance can be improved.

  Examples of the polyamide-based resin include nylon-6,6, nylon-6,10, nylon-6T composed of hexamethylenediamine and terephthalic acid, nylon-6I composed of hexamethylenediamine and isophthalic acid, nonanediamine and terephthalic acid. Nylon-9T composed of: Nylon-M5T composed of methylpentadiamine and terephthalic acid, Nylon-6,12 composed of caprolactam and lauryllactam, and the like. Further, a copolymer of the above resin and at least one of nylon-6, nylon-11, and nylon-12 may be used. These resins can be used alone or in combination of two or more. Further, amorphous aromatic polyamide (amorphous nylon) obtained by polycondensation reaction between an aliphatic diamine such as hexamethylene diamine and a dicarboxylic acid such as terephthalic acid or isophthalic acid or a derivative thereof may be used. When a polyamide resin is used as the material of the outer layer 1, the same polyamide resin as that of the outer layer 1 may be used as the material of the first base resin layer 311.

 The first adhesive layer 312 has a function of bonding the first base resin layer 311 and other layers.

  Examples of the material of the first adhesive layer 312 include a copolymer of ethylene and a vinyl group-containing monomer, a copolymer of propylene and a vinyl group-containing monomer, and a copolymer of 1-butene and a vinyl group-containing monomer. -A copolymer of a butene and a vinyl group-containing monomer. Among these, a copolymer of ethylene and a vinyl group-containing monomer is preferable. Thereby, it has a favorable external appearance and pinhole resistance, and thickness can be made thinner than the conventional multilayer film.

  As the copolymer of ethylene and a vinyl group-containing monomer, a random copolymer, a graft copolymer, a block copolymer, or a graft copolymer is used, and a random copolymer is particularly preferable. Thereby, adhesiveness can be improved.

  Specifically, as a copolymer of ethylene and a vinyl group-containing monomer, maleic anhydride graft-modified linear low-density polyethylene (hereinafter referred to as “LLDPE-g-MAH”), ethylene-vinyl acetate copolymer ( Hereinafter, referred to as “EVA resin”), ethylene-methyl methacrylate copolymer (hereinafter referred to as “EMMA resin”), ethylene-ethyl acrylate copolymer (hereinafter referred to as “EEA resin”), ethylene-methyl. Acrylate copolymer (hereinafter referred to as "EMA resin"), ethylene-ethyl acrylate-maleic anhydride copolymer (hereinafter referred to as "E-EA-MAH resin"), ethylene-acrylic acid copolymer (hereinafter referred to as "E-EA-MAH resin"). , "EAA resin"), ethylene-methacrylic acid copolymer (hereinafter referred to as "EMAA resin"), Iono. Chromatography (hereinafter, referred to as. "ION resin"), and the like. The methacrylic acid copolymerization ratio of the EMAA resin is not particularly limited, but is preferably 5% by weight or more and 20% by weight or less, more preferably 5% by weight or more and 10% by weight or less, and more preferably 8% by weight or more. It is more preferably 10% by weight or less, and most preferably 9% by weight. Thereby, a favorable external appearance and pinhole resistance can be improved. In particular, the copolymer of ethylene and a vinyl group-containing monomer is preferably at least one of LLDPE-g-MAH, EMAA resin, and ION resin. Thereby, it is possible to have good impact resistance and pinhole resistance, whereby the multilayer film 100 is made thinner than the conventional multilayer film while maintaining the same performance as the conventional multilayer film. be able to.

 Furthermore, when the first adhesive layer 312 is an ethylene-vinyl alcohol copolymer, it has good impact resistance, pinhole resistance, and oxygen barrier properties, whereby the multilayer film 100 is different from the conventional multilayer film. In addition to being able to be made thinner than conventional multilayer films while maintaining equivalent impact resistance and pinhole resistance, it can also exhibit oxygen barrier properties.

  The ION resin refers to a copolymer of ethylene and a small amount of acrylic acid or methacrylic acid having an ion bridge structure by salt formation between an acid portion and a metal ion.

  The thickness of each layer of the first adhesive layer 312 is not particularly limited, but is preferably 0.4 μm or more and 20 μm or less, more preferably 0.5 μm or more and 19 μm or less, and 0.6 μm or more and 18 μm. More preferably, it is as follows. When the thickness of each layer of the first adhesive layer 312 is within the above range, the multilayer film 100 has a good appearance and good pinhole resistance and can be made thinner than the conventional multilayer film. it can.

  The thickness of the first repetitive laminated portion 31 composed of the first base resin layer 311 and the first adhesive layer 312 is preferably 0.5 μm or more and 40 μm or less, preferably 1 μm or more and 35 μm or less. Preferably there is. When the thickness is within the above range, the pinhole resistance is particularly excellent.

<Oxygen barrier layer 4>
The oxygen barrier layer 4 has a function of shielding oxygen.

 As a material constituting the oxygen barrier layer 4, for example, a polyvinyl alcohol resin, an EVOH resin, a vinylidene chloride resin, or a polyamide-based resin having an aromatic ring as a diamine component is used. Among these, EVOH resin is preferable. Thereby, oxygen barrier property can be improved more.

  The ethylene copolymerization ratio of the EVOH resin is not particularly limited, but is preferably 20 mol% or more and 50 mol% or less, more preferably 30 mol% or more and 40 mol% or less, and more preferably 30 mol% or more. More preferably, it is 35 mol% or less. When the ethylene copolymerization ratio is within the above range, oxygen barrier properties are particularly excellent.

 The thickness of the oxygen barrier layer 4 is not particularly limited, but is preferably 1 μm or more and 30 μm or less, and more preferably 2 μm or more and 25 μm or less. When the thickness of the oxygen barrier layer 4 is within the above range, the multilayer film 100 can impart good oxygen barrier properties.

  Examples of the oxygen barrier layer 4 include a copolymer of ethylene and a vinyl group-containing monomer, a copolymer of propylene and a vinyl group-containing monomer, a copolymer of 1-butene and a vinyl group-containing monomer, and 2-butene and vinyl. A copolymer with a group-containing monomer may be used. Among these, a copolymer of ethylene and a vinyl group-containing monomer is preferable. Thereby, it has favorable softness | flexibility and bending resistance, and thickness can be made thinner than the conventional multilayer film.

  The oxygen barrier layer 4 may be formed of a plurality of resin layers.

<Second resin layer 5>
In the multilayer film 100 of the first embodiment, the second resin layer 5 is formed by laminating three layers of the second repeated laminated portion 51, and each of the second repeated laminated portions 51 includes the second base resin layer 511 and the second adhesive. It is composed of layer 512. Thereby, pinhole resistance can be improved.

  The number of stacked layers of the second repeated stacked portion 51 is not particularly limited as long as it is plural or more, but is preferably 2 parts or more and 20 parts or less, more preferably 3 parts or more and 15 parts or less, Most preferably, it is 4 parts or more and 10 parts or less. Thereby, it is possible to achieve a balance between thinning of the multilayer film 100 and pinhole resistance. Furthermore, the appearance of the multilayer film 100 is also excellent.

 Note that the number of stacked layers of the first repeated stacked unit 31 and the number of stacked layers of the second repeated stacked unit 52 may be the same or different, but are preferably the same. Thereby, it has a favorable external appearance and pinhole resistance, and thickness can be made thinner than the conventional multilayer film.

 The thickness of each layer of the second base resin layer 511 is not particularly limited, but is preferably 0.05 μm or more and 20 μm or less, more preferably 0.1 μm or more and 19 μm or less, 0.2 μm or more, More preferably, it is 18 μm or less. When the thickness of each layer of the second base resin layer 511 is within the above range, the multilayer film 100 has a good appearance and good pinhole resistance, and is thinner than the conventional multilayer film. be able to.

 The material of the second base layer 511 may be the same as or different from the first base resin layer 311 described above, but it is preferable to use the same material. Thereby, the pinhole resistance on the back surface of the multilayer film 100 is excellent.

 Specifically, as with the material of the first base resin 311, for example, a thermoplastic resin such as a polyamide resin, a polyethylene resin, a polypropylene resin, a polyester resin, a polycarbonate resin, or a polystyrene resin is used. Among these, one or more resins selected from polyamide resins, polyethylene resins, polypropylene resins, and polyester resins are preferable. Thereby, pinhole resistance can be improved.

 The second adhesive layer 512 has a function of bonding the second base resin layer 511 and other layers.

  The material of the second adhesive layer 512 may be the same as or different from that of the first adhesive layer 312, but it is preferable to use the same material. Thereby, the pinhole resistance of the multilayer film 100 can be improved.

  Specifically, copolymers of ethylene and vinyl group-containing monomers, copolymers of propylene and vinyl group-containing monomers, copolymers of 1-butene and vinyl group-containing monomers, 2-butene and vinyl group-containing Examples thereof include a copolymer with a monomer. Among these, a copolymer of ethylene and a vinyl group-containing monomer is preferable. Thereby, it has a favorable external appearance and pinhole resistance, and thickness can be made thinner than the conventional multilayer film.

  The thickness of each layer of the second adhesive layer 512 is not particularly limited, but is not particularly limited, but is preferably 0.4 μm or more and 20 μm or less, more preferably 0.5 μm or more and 19 μm or less, and 0 More preferably, it is 6 μm or more and 18 μm or less. When the thickness of each layer of the second adhesive layer 512 is within the above range, the multilayer film 100 has a good appearance and good pinhole resistance, and can be made thinner than the conventional multilayer film. it can.

  The thickness of the second repeated laminated portion 51 composed of the second base resin layer 511 and the second adhesive layer 512 is preferably 0.5 μm or more and 40 μm or less, respectively, and preferably 1 μm or more and 35 μm or less. Preferably there is. When the thickness is within the above range, the pinhole resistance is particularly excellent.

  The average thickness of each layer of the first repeating part 31 and the average thickness of each layer of the second repeating part 51 may be the same or different, but are preferably the same. Thereby, it becomes a symmetrical structure on both sides of the oxygen barrier layer 4, and pinhole resistance of both surfaces can be made equal.

  Further, it is preferable that the first resin layer 3 and the second resin layer 5 have a substantially symmetrical structure with the oxygen barrier layer 4 interposed therebetween. As a result, the pinhole resistance can be improved on both the first resin layer 3 side and the second resin layer 5 side, whereby the pinhole resistance of the multilayer film 100 can be further improved.

<Adhesive layer 6>
The adhesive layer 6 improves the adhesive strength between the core layer 7 and the second resin layer 5 described later. In addition, the waist strength, pinhole resistance, flexibility or moldability of the multilayer film 100 can be improved.

  The material of the adhesive layer 6 may be the same as or different from the adhesive layer 2 described above.

 Specifically, an adhesive polyolefin-based resin or the like is used, an ethylene-methacrylate-glycidyl acrylate terpolymer, or a monobasic unsaturated fatty acid, a dibasic unsaturated fatty acid, or an anhydride thereof. Products obtained by grafting products (maleic acid grafted ethylene-vinyl acetate copolymer, maleic acid grafted ethylene-α-olefin copolymer, etc.) are used. As the monobasic unsaturated fatty acid, acrylic acid, methacrylic acid or the like is used. As the dibasic unsaturated fatty acid, maleic acid, fumaric acid, itaconic acid or the like is used.

  The thickness of the adhesive layer 6 may be the same as or different from the thickness of the adhesive layer 2.

  Specifically, the thickness of the adhesive layer 6 is not particularly limited, but is preferably 2 μm or more and 70 μm or less, and more preferably 3 μm or more and 60 μm or less. When the thickness of the adhesive layer 6 is within the above range, the multilayer film 100 imparted with good adhesive strength can be obtained at a relatively low cost.

<Core layer 7>
The core layer 7 has pinhole resistance.

 The material of the core layer 7 is made of a resin composition containing a biomass-derived polyolefin formed by polymerization of a monomer containing biomass-derived ethylene.

 In the present invention, “derived from biomass” means containing carbon derived from a biomass raw material produced from an alcohol obtained using a plant as a raw material.

 In the present invention, the biomass-derived polyethylene resin is a homopolymer of biomass-derived ethylene derived from bioethanol obtained from a biomass raw material, or a copolymer of the biomass-derived ethylene and a small amount of other comonomer. .

 Specifically, high density polyethylene (density 0.940 g / cm 3 or more) obtained by polymerizing ethylene derived from bioethanol, medium density polyethylene (density 0.925 or more and less than 0.940 g / cm 3), high pressure method There may be mentioned low density polyethylene (density less than 0.925 g / cm 3), linear low density polyethylene (copolymer of ethylene and α-olefin), and mixtures thereof.

 As a method for producing biomass-derived ethylene and biomass-derived α-olefin, bioethanol is produced by fermenting sugar solution and starch obtained from plants such as sugarcane, corn, and sweet potato with microorganisms such as yeast according to conventional methods. Then, this is heated in the presence of a catalyst, and biomass-derived ethylene and biomass-derived α-olefin (1-butene, 1-hexene, etc.) can be obtained by intramolecular dehydration reaction or the like. Next, using the obtained biomass-derived ethylene and biomass-derived α-olefin, a biomass-derived polyethylene resin can be produced in the same manner as in the production of a petroleum-derived polyethylene resin.

 The method for producing biomass-derived ethylene, biomass-derived α-olefin, and plant-derived polyethylene resin is described in detail in, for example, JP-T-2011-506628.

 Examples of the biomass-derived polyethylene resin suitably used in the present invention include Green PE manufactured by Braskem S.A.

 Use of the biomass-derived polyethylene resin results in obtaining a polymer from a carbon neutral monomer, thereby realizing a reduction in environmental burden.

 The thickness of the core layer 7 is not particularly limited, but is preferably 2 μm or more and 80 μm or less, and more preferably 3 μm or more and 70 μm or less. When the thickness of the core layer 7 is within the above range, it can have pinhole resistance.

<Seal layer 8>
The seal layer 8 has a function of content resistance and a function of suitability for sealing with a mating material. The content resistance refers to a property in which the seal layer 8 does not lose the function related to the sealability with the counterpart material due to the chemical or oil when the content is food containing a large amount of chemical or oil.

  Examples of the material of the sealing layer 8 include a low density polyethylene resin (hereinafter referred to as “LDPE resin”), a linear low density polyethylene resin (hereinafter referred to as “LLDPE resin”), and a medium density polyethylene resin (hereinafter referred to as “LDPE resin”). MDPE resin ”), high-density polyethylene resin (hereinafter referred to as“ HDPE resin ”), polypropylene resin (hereinafter referred to as“ PP resin ”), EVA resin, EMMA resin, EEA resin, EMA resin, E-EA. -Resins such as MAH resin, EAA resin, EMAA resin, and ION resin are used. These resins can be used alone or in combination of two or more. In particular, as a material for the seal layer 8, LLDPE resin and EVA resin are preferable in terms of excellent transparency and seal strength.

 The seal layer 8 preferably has an easy peel function. Thereby, when the multilayer film 100 is used for a package, it can be easily opened. In order to provide the easy peel function, the material of the seal layer 8 is, for example, 10 parts by weight or more and 90 parts by weight or less of an ethylene copolymer such as EMAA resin or EMMA resin, and 10 parts by weight or more and 90 parts by weight of PP resin. What contains the following is used. By making the ethylene copolymer 10 parts by weight or more, the seal layer 8 has a good easy peel property. By making the ethylene copolymer 90 parts by weight or less, variation in peel strength of the seal layer 8 is reduced. The seal layer 8 may not have an easy peel function.

  The thickness of the seal layer 8 is not particularly limited, but is preferably 2 μm or more and 80 μm or less, and more preferably 3 μm or more and 70 μm or less. When the thickness of the seal layer 8 is within the above range, the multilayer film 100 having a good appearance can be obtained at a relatively low cost.

  By setting it as such embodiment, it became clear that the multilayer film 100 in 1st Embodiment has favorable pinhole resistance. Thereby, this multilayer film 100 can make thickness thinner than the conventional multilayer film, maintaining the performance equivalent to the conventional multilayer film. Furthermore, good impact resistance can be exhibited.

  Thus, the reason why the multilayer film 100 in the first embodiment can be made thinner than the conventional multilayer film and has good pinhole resistance compared to the conventional multilayer film is as follows. It seems like.

  First, in order to improve the pinhole resistance of the multilayer film 100, it seems effective to improve the impact resistance and the bending resistance of the multilayer film 100. In the multilayer film 100, for example, with respect to an impact from the outer layer 1 side, the resistance to the impact of the first repeating portion 31 on the outermost layer 1 side among the plurality of first repeating portions 31 constituting the first resin layer 31. Force, resistance force against the impact of the first repeating portion 31 inside thereof, resistance force against the impact of the second repeating portion 51 existing on the opposite side of the oxygen barrier layer 4, and stress at the repeating interface of the first repeating portion 31 The degree of impact resistance is determined by the dispersion. Among these, it is considered that the stress distribution at the interface of the repeated portion is particularly effective for improving the impact resistance. Therefore, since the multilayer film 100 of this invention has many layers with the 1st repetition lamination | stacking part 31 and the 2nd repetition lamination | stacking part 51, it is thought that impact resistance improves.

  Moreover, regarding the bending resistance, the bending resistance becomes better as the flexibility of the film is improved. Therefore, it is considered that the multilayer film 100 of the present invention having a plurality of thin repeating portions is superior in flex resistance to the multilayer film having a thick resin layer.

Since these impact resistance and bending resistance are excellent, it is considered that the multilayer film 100 of the present invention can improve impact resistance and pinhole resistance.
Second Embodiment
Next, 2nd Embodiment of the multilayer film of this invention is described.

  FIG. 2 is a cross-sectional view showing the multilayer film 100 of the second embodiment.

  Hereinafter, although the second embodiment will be described, the description will focus on the differences from the first embodiment, and the description of the same matters will be omitted. In the present embodiment, the same components as those of the first embodiment are denoted by the same reference numerals as those of the components described above, and detailed description thereof is omitted.

  In the multilayer film 100 of the second embodiment, the first resin layer 3 and the second resin layer 5 have an asymmetric structure across the oxygen barrier layer 4.

  The 1st resin layer 3 is comprised by the 1st repeating lamination | stacking part 31 of 3 layers similarly to 1st Embodiment. On the other hand, the second resin layer 5 is composed of two layers of second repeating portions 51. As a result, when pinhole resistance is further required on the first resin layer 3 side, the thickness of the second resin layer 5 is reduced while maintaining the pinhole resistance on the first resin layer 3 side. By doing so, the overall thickness can be reduced.

  In this way, by controlling the number of laminated layers of at least one of the first resin layer 3 and the second resin layer 5, the required pinhole resistance and the thickness of the multilayer film 100 can be balanced. Can be planned.

<Third Embodiment>
Next, a third embodiment of the multilayer film of the present invention will be described.

  FIG. 3 is a cross-sectional view showing the multilayer film 100 of the third embodiment.

  In the following, the third embodiment will be described. The description will focus on the differences from the first embodiment, and the description of the same matters will be omitted. In the present embodiment, the same components as those of the first embodiment are denoted by the same reference numerals as those of the components described above, and detailed description thereof is omitted.

  In the multilayer film 100 of the third embodiment, a first repeated laminated portion 31 ′ having a different thickness is provided between the adhesive layer 2 and the first resin layer 3. Thereby, the pinhole resistance on the first resin layer 3 side can be further improved.

 Each layer constituting the multilayer film 100 of the present invention is an antioxidant, a slip agent, an antiblocking agent, an antistatic agent, an ultraviolet absorber, a resin modifier, a dye, a pigment, etc., as long as the gist of the present invention is not impaired. You may contain additives, such as a coloring agent and a stabilizer, impact resistance imparting agents, such as a fluororesin and a silicone rubber, and inorganic fillers, such as a titanium oxide, a calcium carbonate, and a talc.

Thus, although the multilayer film of this invention was demonstrated using 1st Embodiment, 2nd Embodiment, and 3rd Embodiment, this invention is not limited to this.

  For example, the first resin layer 3 and the second resin layer 5 may be formed with different thicknesses of the first repeated laminated portion 31 and the second repeated laminated portion.

  Moreover, the thickness of the 1st base resin layer 311 and the 1st contact bonding layer 312 which comprise the 1st repeating lamination | stacking part 31 may each differ.

  Similarly, the thicknesses of the second base resin layer 511 and the second adhesive layer 512 constituting the second repeated laminated portion may be different from each other.

  Further, the outer layer 1 and the seal layer 8 may not be provided.

  A plurality of oxygen barrier layers 4 may be provided between the first resin layer 3 and the second resin layer 5.

<Method for producing multilayer film>
The multilayer film 100 as described above includes, for example, an outer layer 1 having an adhesive layer 2, a first resin layer 3, an oxygen barrier layer 4, a second resin layer 5, a core layer 7 having an adhesive layer 6, and a seal. It is obtained by manufacturing the layer 8 separately and then bonding them with a laminator or the like. The multilayer film 100 includes an outer layer 1 having an adhesive layer 2, a first resin layer 3, an oxygen barrier layer 4, a second resin layer 5, a core layer 7 having an adhesive layer 6, and a seal layer 8 that are air-cooled. Alternatively, it can also be obtained by forming a film by a water-cooled coextrusion inflation method or a coextrusion T-die method. In particular, the method of forming a film by the coextrusion T-die method is preferable from the viewpoint of control of the thickness of the multilayer film 100 and transparency, and it is possible to form a film by using an appropriate feed block and die.

<Packaging body>
Next, the packaging body will be described.

  FIG. 4 is a cross-sectional view showing an example of the package of the present invention.

  The packaging body 200 shown in FIG. 4 includes a lid member 201 and a bottom member 202. The bottom material 202 is obtained by forming a recess (pocket) 203 in the multilayer film 100. The recess 203 accommodates contents such as food, beverages or industrial parts. After the contents are stored in the recess 203, the lid member 201 is sealed to the bottom member 202, and the recess 203 of the bottom member 202 is sealed.

  The multilayer film 100 as described above is used for the bottom material 202 of the package 200. The bottom material 202 is formed so that the outer layer 1 is on the outer side and the sealing layer 8 is on the inner side of the multilayer film 100.

Examples of the material of the lid member 201 include a biaxially stretched polypropylene film (OPP film) and a biaxially stretched polyethylene terephthalate film (VMPT) on which a metal oxide is deposited.
Film) and a film in which a polyethylene resin is laminated is used.

  Moreover, since the multilayer film 100 is used for the bottom material 202 of the package 200 as described above, the package 200 has good impact resistance and pinhole resistance and is thicker than the conventional multilayer film. Can be made thinner. Thereby, this packaging body 200 shows favorable impact resistance and pinhole resistance at the time of use, and can reduce the quantity of the multilayer film used as a waste after use. Furthermore, this package 200 can reduce the risk of discarding the product (package containing the contents) due to the pinhole formation due to good impact resistance and pinhole resistance.

  In the present embodiment, the multilayer film 100 is used for the bottom material 202 of the package 200. However, the present invention is not limited to this, and the multilayer film 100 may be used for both the lid material and the bottom material. .

 EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this.

(Example 1)
<Manufacture of multilayer film>
(Example 1)
In order to obtain the multilayer film 100 shown in FIG. 1, each of the outer layer 1, the adhesive layer 2, the first resin layer 3, the oxygen barrier layer 4, the second resin layer 5, the adhesive layer 6, the core layer 7, and the seal layer 8. As shown in Table 1, the resin material for forming was prepared. The raw material of the used resin material is as follows.

Outer layer 1: Polyamide resin, 6-Ny (trade name “1022B”, manufactured by Ube Industries)
Adhesive layer 2: Adhesive resin, LLDPE-g-MAH (trade name “NF536”, manufactured by Mitsui Chemicals, Inc.)
First base resin layer 311 of first resin layer 3: polyamide resin, 6-Ny (trade name “1022B”, manufactured by Ube Industries, Ltd.)
First adhesive layer 312 of the first resin layer 3: adhesive resin, LLDPE-g-MAH (trade name “NF536”, manufactured by Mitsui Chemicals, Inc.)
Oxygen barrier layer 4: Adhesive resin, LLDPE-g-MAH (trade name “NF536”, manufactured by Mitsui Chemicals, Inc.)
Second base resin layer 511 of second resin layer 5: polyamide resin, 6-Ny (trade name “1022B”, manufactured by Ube Industries, Ltd.)
Second adhesive layer 512 of the second resin layer 5: adhesive resin, LLDPE-g-MAH (trade name “NF536”, manufactured by Mitsui Chemicals, Inc.)
Adhesive layer 6: Adhesive resin, LLDPE-g-MAH (trade name “NF536”, manufactured by Mitsui Chemicals, Inc.)
Core layer 7: Sugarcane-derived linear low-density polyethylene resin (trade name: SLH218, manufactured by Braschem)
Seal layer 8: polyethylene resin, LLDPE (trade name “2022L”, manufactured by Prime Polymer Co., Ltd.)
The polyamide-based resin is supplied to an extruder adjusted to 275 ° C., and the adhesive resin and the polyethylene resin are supplied to an extruder adjusted to 240 ° C., respectively, outer layer 1 / adhesive layer 2 / laminate 3 / oxygen. The multilayer film 100 was obtained by performing coextrusion using a feed block and a die so that the order of barrier layer 4 / laminate 5 / adhesive layer 6 / core layer 7 / sealing layer 8 was obtained.

 In this embodiment, the first resin layer 3 is obtained by alternately stacking five first base resin layers 311 and four first adhesive layers 312, and the total number of layers is nine. The second resin layer 5 is obtained by alternately stacking five second base resin layers 511 and four second adhesive layers 512, and the total number of layers is nine. In the multilayer film 100 of Example 1, the total number of layers was 24, and the thickness of the entire film was 150 μm as measured using a Digimatic indicator (product number: ID-C112 (manufactured by Mitutoyo Corporation)). Regarding the thickness, the film was cut with a microtome, and the SEM image was measured with a scanning electron microscope (product number: VE-8800 (manufactured by Keyence Corporation)) to determine the thickness of each layer. It was shown in 1.

(Example 2)
The number of first base resin layers 311 constituting the first resin layer 3 is changed to nine, the number of first adhesive layers 312 is changed to eight, and the second resin layer 5 is constituted. The multilayer film of Example 2 (total), except that the number of layers of the second base resin layer 511 was changed to 9 and the number of layers of the second adhesive layer 512 was changed to 8 layers. Number of layers: 40 layers, thickness: 150 μm) was produced.

(Example 3)
Example 3 is the same as Example 1 except that the thicknesses of the first resin layer 3 and the second resin layer 5 are changed to 20 μm and the thickness of the seal layer 8 is changed to 51 μm. A multilayer film (total number of layers: 24 layers, thickness: 150 μm) was produced.

Example 4
Changing the thickness of the outer layer 1 to 15 μm, changing the thickness of the adhesive layer 2 to 6 μm, changing the thickness of the first resin layer 3 and the second resin layer 5 to 21 μm, the oxygen barrier layer 4 In the same manner as in Example 1, except that the thickness of the adhesive layer 6 was changed to 7 μm, the thickness of the adhesive layer 6 was changed to 6 μm, and the thickness of the seal layer 8 was changed to 24 μm. 4 multilayer films (total number of layers: 24 layers, thickness: 100 μm) were produced.

(Example 5)
Changing the thickness of the outer layer 1 to 9 μm, changing the thickness of the adhesive layer 2 to 4 μm, changing the thickness of the first resin layer 3 and the second resin layer 5 to 13 μm, the oxygen barrier layer 4 In the same manner as in Example 1, except that the thickness of the adhesive layer 6 was changed to 4 μm, the thickness of the adhesive layer 6 was changed to 4 μm, and the thickness of the seal layer 8 was changed to 13 μm. 5 multilayer films (total number of layers: 24 layers, thickness: 60 μm) were produced.

(Example 6)
The multilayer film of Example 6 (total) in the same manner as in Example 1 except that the resin of the seal layer 8 was changed to a sugarcane-derived linear low-density polyethylene resin (trade name: SLH218, manufactured by Braschem). Number of layers: 24 layers, thickness: 150 μm) was produced.

(Example 7)
The multilayer film of Example 7 (total number of layers: 24 layers, thickness) was the same as Example 1 except that the thickness of the core layer 7 was changed to 20.5 μm and the thickness of the seal layer 8 was changed to 20 μm. : 150 μm).

(Example 8)
The multilayer film of Example 8 (total number of layers: similar to Example 1) except that the resin of the core layer 7 was changed to sugarcane-derived low-density polyethylene-based resin (trade name: SEB853, manufactured by Braschem). 24 layers, thickness: 150 μm) were produced.

(Comparative Example 1)
The thickness of the outer layer 1 is changed to 23 μm, the thickness of the adhesive layer 2 is changed to 44 μm, and the first base resin layer 311 (thickness: 16 μm) is used instead of the first resin layer 3 The multilayer film of Comparative Example 1 (the same as Example 1) except that a single second base resin layer 511 (thickness: 16 μm) was used instead of the second resin layer 5. Outer layer / adhesive layer / thermoplastic resin layer / oxygen barrier layer / thermoplastic resin layer / adhesive layer / core layer / seal layer, total number of layers: 8 layers, thickness: 150 μm).

(Comparative Example 2)
Changing the thickness of the outer layer 1 to 15 μm, changing the thickness of the adhesive layer 2 to 31 μm, changing the thickness of the thermoplastic resin layers 31 and 51 to 10 μm, and changing the thickness of the oxygen barrier layer 4 to In the same manner as in Comparative Example 1 except that the thickness was changed to 6 μm, the thickness of the adhesive layer 6 was changed to 10 μm, and the thickness of the seal layer 8 was changed to 18 μm, the multilayer film of Comparative Example 2 ( Outer layer / adhesive layer / first resin layer / oxygen barrier layer / second resin layer / adhesive layer / core layer / seal layer, total number of layers: 8 layers, thickness: 100 μm).

(Comparative Example 3)
Changing the thickness of the outer layer 1 to 9 μm, changing the thickness of the adhesive layer 2 to 18 μm, changing the thickness of the thermoplastic resin layers 31 and 51 to 6 μm, and changing the thickness of the oxygen barrier layer 4 to In the same manner as in Comparative Example 1 except that the thickness was changed to 4 μm, the thickness of the adhesive layer 6 was changed to 6 μm, and the thickness of the seal layer 8 was changed to 11 μm, the multilayer film of Comparative Example 3 ( Outer layer / adhesive layer / first resin layer / oxygen barrier layer / second resin layer / adhesive layer / core layer / seal layer, total number of layers: 8 layers, thickness: 60 μm).

 The multilayer films of Examples 1 to 8 and Comparative Examples 1 to 4 produced as described above were evaluated for impact resistance, flex resistance, stretch rate, and moldability as follows.

(Impact resistance)
A sample was prepared by cutting the multilayer film into a width of 100 mm and a length of 100 mm. This produced sample was set in a falling weight impact tester (manufactured by Instron). Then, a striker having a diameter of 10 mm was made to collide with the outer layer 1 (front surface) side and the seal layer 8 (back surface) side of the multilayer film at a dropping speed of 2.7 m / sec. This test was performed for each of the 20 samples, and the amount of energy required for film penetration was calculated. The calculation was performed by a method according to Japanese Industrial Standard (JIS) K7124-2.

(Flexibility)
Based on ASTMF392, the measurement regarding the bending resistance of a multilayer film was performed with the gelboflex tester (made by Rigaku Corporation). Specifically, a sample of a multilayer film is wound and fixed on two discs having a diameter of 8.8 cm facing each other of a gelbo flex tester, and twisting is applied to the multilayered film formed into a cylindrical shape, thereby performing bending treatment. went. This bending treatment was performed 2000 times at a temperature of 23 ° C. This test was performed on 10 samples, and the number of pinholes generated in each sample was counted. The average number of pinholes per sample was calculated.

(Thermomechanical analysis)
Using a thermomechanical analyzer (manufactured by SII), the elongation at room temperature of the multilayer film was set to 0%, and the elongation at 200 ° C. of the multilayer film was measured to calculate the elongation (%). The measurement was carried out under conditions of a heating rate of 5 ° C./min and a load of 9.8 mN.

(Formability)
Using a vacuum forming machine, the drawdown situation when the film was heated and melted with a hot platen was determined according to the following criteria. The film had an area of 32 × 32 cm. The heating was performed under conditions of about 200 to 250 ° C. for about 5 seconds.

 A: Drawdown is slight or hardly occurs.

 B: Drawdown is large and molding is difficult.

 The evaluation results are shown in Table 1.

As shown in Table 1, the multilayer films of Examples 1 to 5 had better pinhole resistance and impact resistance than the multilayer films of Comparative Examples 1 to 3. In addition, the multilayer films of Examples 1 to 5 are good because the thermal deformability by TMA is low compared to the multilayer films of Comparative Examples 1 to 3, and the drawdown is suppressed and the moldability is also good. The multilayer film of the present disclosure having excellent pinhole resistance and impact resistance has been found to be suitable for skin pack packaging.

 Although the multilayer film for skin pack packaging of this indication is used for skin pack packaging uses, such as a foodstuff, a pharmaceutical, industrial parts, and an electronic material, the application range is not restricted to this.

DESCRIPTION OF SYMBOLS 1 Outer layer 2 Adhesion layer 3 1st resin layer 31 1st repetition part 311 1st base resin layer 312 1st adhesion layer 4 Oxygen barrier layer 5 2nd resin layer 51 2nd repetition part 511 2nd base resin layer 512 2nd adhesion Layer 6 Adhesive layer 7 Core layer 8 Seal layer 100 Multilayer film 200 Packaging body 201 Cover material 202 Bottom material 203 Concave portion

Claims (9)

 An outer layer, a first resin layer, an oxygen barrier layer, a second resin layer, a core layer, and a seal layer are laminated in this order, and the first resin layer includes a first base layer A plurality of first repetitive laminated portions composed of a resin layer and a first adhesive layer are laminated, and the second resin layer is a second repetitive laminated portion composed of a second base resin layer and a second adhesive layer. A multilayer film comprising a resin composition comprising a biomass-derived polyolefin obtained by polymerizing a monomer containing biomass-derived ethylene.   2. The multilayer film according to claim 1, wherein the number of laminated layers of the first repeated laminated portion and the number of laminated layers of the second repeated laminated portion are the same.   The multilayer film according to claim 1 or 2, wherein the number of laminations of the first repeated lamination part is 2 parts or more and 20 parts or less.   The multilayer film according to any one of claims 1 to 3, wherein the number of laminations of the second repeated lamination part is 2 parts or more and 20 parts or less.   The multilayer film according to any one of claims 1 to 4, wherein the thickness of each part of the first repeated lamination part is 0.5 µm or more and 40 µm or less, respectively.   The multilayer film according to any one of claims 1 to 5, wherein the thickness of each part of the second repeated lamination part is 0.5 µm or more and 40 µm or less, respectively.   The multilayer film according to any one of claims 1 to 6, wherein the first base resin and the second base resin are the same resin.   The multilayer film according to any one of claims 1 to 7, wherein the first base resin is one or more resins selected from a polyamide resin, a polyethylene resin, a polypropylene resin, and a polyester resin. A package comprising the multilayer film according to any one of claims 1 to 8.