JP2017141057A - Partition material film and multistage package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multistage package capable of reducing the amount of used packaging materials even while only a small number of articles are packaged, and a coextrusion multilayer film suitably used as a film constituting the multistage package.SOLUTION: This partition material film is provided with: a lid material film; at least one partition material film; and a bottom material film. The bottom material film is provided with: a bottom surface; a side wall erected from the outer periphery of the bottom surface; and a flange part formed at the end of the side wall in an erecting direction. The partition material film is used for a multistage package that has a housing part between the films. The multistage package is a coextrusion multilayer film in which a tensile elastic modulus is 200 MPa-1000 MPa, and a thickness is 40 μm-200 μm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a partition material film used as a partition film of a multistage package suitable as a food packaging container, and a multistage package using the film.

In recent years, the food industry has been required to reduce waste to cope with environmental problems. On the other hand, the amount of packaging material used is increasing because food solids are becoming smaller and packaging of small quantities is progressing to give preservation hygiene.
The same situation applies to deep-drawn packages used for packaging sliced ham, sliced bacon, and the like.

  For example, Patent Document 1 discloses a composite film for deep-drawing packaging bottom material that is soft but has a certain degree of stiffness (rigidity) and good shape retention.

JP2003-136648

However, as a bottom material for deep-drawn packaging, a certain amount of thickness is necessary to maintain its shape, and a certain amount of thickness is necessary for the lid material to have its function. There was a limit to reducing the amount of materials used.
Therefore, the present invention provides a multistage package that can reduce the amount of packaging material used while being a small amount of individual packages, and a partition material film that is suitably used as a film constituting the multistage package. Is an issue.

  As a result of intensive studies to solve the problem of reducing the amount of packaging material used, the present inventors have found this problem from a viewpoint completely different from the viewpoint of reducing the resin material used conventionally. It is found that the problem of trade-off between small quantity individual packaging and reduction of the amount of packaging material can be solved at the same time, and the following multistage packaging body and the partition suitably used for the multistage packaging body The film was completed.

Hereinafter, reference numerals in the drawings are indicated in parentheses at corresponding portions, but the correspondence is shown for the sake of clarity, and the present invention is not limited to the form of the drawings.
A first aspect of the present invention includes a lid material film (10), at least one partition material film (20), and a bottom material film (30), and the bottom material film (30) is a bottom surface (32), A side wall (34) erected from the outer periphery of the bottom surface (32), and a flange part (36) formed at the end of the side wall (34) in the erection direction, are provided between the respective films. A partition material film (20) used for a multistage package (100) having (42, 44), having a tensile elastic modulus of 200 MPa to 1000 MPa, a thickness of 40 µm to 200 µm, and a coextruded multilayer film It is a partition material film (20) which is.

1st aspect of this invention WHEREIN: It is preferable that the partition material film (20) is equipped with the gas barrier layer and the easily peelable layer. By providing the gas barrier layer, gas barrier properties can be provided between the upper and lower accommodating portions of the partition material film (20), and the gas barrier property of the lower accommodating portion can be maintained even after the upper accommodating portion is opened, and accommodated. Effective for long-term storage of goods.
Moreover, providing an easy-peelability between a lid | cover material film (10) and a partition material film (20) and / or a partition material film (20), and a bottom material film (30) by providing an easy-release layer. Can do.

  The second aspect of the present invention comprises a lid material film (10), at least one partition material film (20), and a bottom material film (30), the bottom material film (30) being a bottom surface (32), A side wall (34) erected from the outer periphery of the bottom surface (32), and a flange part (36) formed at the end of the side wall (34) in the erection direction, are provided between the respective films. It is a multistage package which has (42,44), Comprising: A partition material film (20) is a multistage package (100) which is the partition material film (20) as described in the 1st aspect of this invention.

  2nd aspect of this invention WHEREIN: It is preferable that the loop stiffness of a bottom material film (30) is 80 to 1000 g. By using such a bottom material film (30), it is possible to impart an appropriate hardness to the bottom material that can maintain the shape as a deep-drawn molded body.

  In the second aspect of the present invention, it is preferable that the lid material film (10) and the bottom material film (30) each comprise a coextruded multilayer film layer. The lid material film (10) and the bottom material film (30) are each constituted by a coextruded film or include a coextruded film, thereby providing the performance of each layer constituting the coextruded film. It becomes possible to make a multifunctional lid or bottom material. As a layer which comprises a coextrusion multilayer film, a gas barrier layer, an easily peelable layer, a sealing layer, an adhesive resin layer etc. can be mentioned, for example.

In the second aspect of the present invention, the oxygen permeability of the lid material film (10), the partition material film (20), and the bottom material film (30) are all 0.1 cc / m ² / day / atm. It is preferably 50 cc / m ² / day / atm or less. By providing each film with the oxygen permeability, it is possible to impart gas barrier properties required for food packaging.

  In the second aspect of the present invention, the partition material film (20) side surface layer in the lid material film (10), or the lid material film (10) side surface layer in the partition material film (20) is an easily peelable layer, The peel strength between the lid material film (10) and the partition material film (20) is 1 N / 15 mm width to 15 N / 15 mm width, and the bottom material film (30) side surface layer of the partition material film (20), or The partition material film (20) side surface layer of the bottom material film (30) is an easily peelable layer, and the peel strength between the partition material film (20) and the bottom material film (30) is 1 N / 15 mm width or more and 15 N / 15 mm width. It is preferable that: Thereby, it is possible to impart easy peelability (easy peel property) between the lid material film (20) / partition material film (20) and / or between the partition material film (209 / bottom material film (30)). It becomes.

  In addition, in the said aspect, since it is preferable to provide easy peelability to both between a cover material film (10) / partition material film (20) and between a partition material film (20) / bottom material film (30). In that case, the peel strength between the partition material film (20) and the bottom material film (30) may be set larger than the peel strength between the lid material film (10) and the partition material film (20). preferable. With this setting, the purchaser first peels off the lid film (10) and takes out the article in the upper storage section between the lid film (10) and the partition film (20). It becomes possible to guide, and even after opening only the upper accommodating part, the gas barrier property of the lower accommodating part can be maintained, which is effective for long-term storage of the contents.

  According to the present invention, it is possible to achieve both a small amount of individual packaging and a reduction in the amount of packaging material used. In addition, a plurality of individual packages are possible in a single packaging process, and production efficiency can be improved. Moreover, not only can a plurality of similar articles be individually packaged and provided as a single product, but a plurality of different types of articles can be individually packaged and provided as a single product. As a result, related dissimilar articles can be provided together, and the needs of consumers can be dealt with in detail. Furthermore, since the bottom and the lid are flat and the bottom is a deep-drawn package having strength, the packages can be stacked (stacked), which makes it easy for retailers to handle.

It is a perspective view of the multistage package 100 which is one Embodiment of this invention. In FIG. 1, it is sectional drawing when cut | disconnecting along the line shown by II-II. It is a figure explaining the layer structure of the partition material film. It is a figure which shows the evaluation method of the loop stiffness of the bottom material film. It is a figure which shows the evaluation method of the rigid property of a bottom material. It is a figure which shows the evaluation result of the rigid property of a bottom material.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings. However, the present invention is not limited to the embodiment. In addition, the figure shown below shows the structure schematically and does not show the magnitude | size and shape of each component accurately.

[Multistage package 100]
The perspective view which concerns on one Embodiment of the multistage package 100 of this invention is shown in FIG. The multistage package 100 of the present invention includes a lid material film 10, at least one partition material film 20, and a bottom material film 30. The lid material film 10 and the partition material film 20 are planar films. The bottom material film 30 is formed by deep drawing, and includes a bottom surface 32, a side wall 34 erected from the outer periphery of the bottom surface 32, and a flange portion 36 formed at an end portion of the side wall 34 in the erection direction. .

  FIG. 2 shows a cross-sectional view of the multi-stage package 100 taken along the line II-II in FIG. In the present specification, the downward direction in FIG. 2 is referred to as the bottom material direction, and the upward direction in FIG. In the illustrated form, a two-stage package 100 having one partition material film 20 is shown, and an upper storage section 42 and a lower storage section 44 are respectively formed. In addition, the partition material film 20 extends by placing the contents on the partition material film 20 or enclosing an inert gas or the like in the storage portion, and the content sinks in the bottom material direction, so that the upper storage portion 42 and a lower storage 44 are formed.

<Partition film 20>
The partition material film 20 is a coextruded multilayer film, and its tensile modulus is preferably 200 MPa or more and 1000 MPa or less, more preferably 330 MPa or more and 800 MPa or less, and particularly preferably 400 MPa or more and 700 MPa or less. . When the contents are placed on the partitioning material film 20 if the elastic modulus is small outside the range, the partitioning material film 20 is excessively stretched, and the lower storage part of the partitioning material film 20 becomes narrow, Moreover, when the partition material film 20 is pulled and the lower housing part is opened, the partition material film 20 extends. On the other hand, if the elastic modulus is large outside this range, even if the contents are placed on the partition material film 20, the partition material film 20 does not stretch, so the storage section on the upper side of the partition material film 20 becomes narrow, and in some cases. The contents push the lid material, and the lid material rises, deteriorating the aesthetic appearance.
Moreover, it is possible to adjust the magnitude | size of each accommodating part by adjusting the tensile elasticity modulus of the partition material film 20 within the said range according to the weight of the contents.

  Further, the thickness of the partition material film 20 is preferably 40 μm or more and 200 μm or less, more preferably 50 μm or more and 160 μm or less, and further preferably 60 μm or more and 130 μm or less. If the thickness is out of the above range and the thickness is too thin, the film strength may be insufficient, and heat sealing may cause problems such as wrinkles in the sealed portion and impaired aesthetics. The problem of the cost increase accompanying an increase, the increase in the weight of a package, and the increase in the amount of waste arises.

(Gas barrier layer)
Examples of the gas barrier layer include a polyamide resin layer and an ethylene-vinyl acetate copolymer saponified product layer.

Polyamide resin layer The partition material film 20 can impart impact strength and gas barrier properties to the film by including a polyamide resin layer. In addition, since the saponified ethylene-vinyl acetate copolymer layer (EVOH layer) described below is relatively brittle, a film is formed by disposing a polyamide resin layer on one or both sides of the EVOH layer. It is possible to improve the impact resistance.

  Polyamide resins suitable for use include, for example, condensation units such as 6 nylon, 66 nylon, 69 nylon, 6-66 nylon, 12 nylon, 11 nylon, 610 nylon, 612 nylon, 6I-6T nylon, and MXD6 nylon. A polymer, these 2 or more types of copolymers, and also a mixture thereof can be mentioned. Among these, 6-66 nylon and 6 nylon are preferable. Further, when importance is attached to gas barrier properties, it is preferable to use MXD6 nylon or a mixture of the MXD6 nylon and other nylons.

  The lower limit of the thickness of the polyamide resin layer is preferably 2 μm or more, more preferably 3 μm or more, and even more preferably 4 μm or more from the viewpoint of obtaining an aesthetic surface shape free of surface roughness and streaks of the film. The upper limit is preferably 25 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less from the viewpoint of film formability.

Ethylene-vinyl acetate copolymer saponified material layer The partition material film 20 can enhance the oxygen gas barrier property by including an ethylene-vinyl acetate copolymer saponified material layer.
The ethylene monomer content of EVOH is not particularly limited, but is preferably 29 mol% or more and 47 mol% or less, more preferably 32 mol% or more and 44 mol% or less from the viewpoint of film formation stability. Further, the saponification degree of EVOH is preferably 90 mol% or more, more preferably 95 mol% or more. By setting the ethylene monomer content and the saponification degree within the above ranges, the coextrudability and strength of the film are improved.

  The thickness of the EVOH layer is preferably 5 μm or more, more preferably 8 μm or more, and even more preferably 10 μm or more, from the viewpoint of obtaining sufficient oxygen gas barrier properties. The upper limit is preferably 30 μm or less, more preferably 25 μm or less, and even more preferably 20 μm or less from the viewpoint of obtaining good film coextrudability and strength.

The oxygen permeability of the partition material film 20 having the gas barrier layer is preferably 0.1 cc / m ² / day / atm to 50 cc / m ² / day / atm, and more preferably 0.1 cc / m ^2. / Day / atm to 20 cc / m ² / day / atm.
The oxygen transmission rate can be measured by using an oxygen transmission rate measuring apparatus OX-TRAN manufactured by Mocon under the condition of 23 ° C. and 0% relative humidity in accordance with JIS K 7126.

(Easy peeling layer (easy peel layer, EP layer))
It is preferable that the partition material film 20 has an easily peelable layer (EP layer). The EP layer is a layer disposed on the surface layer on the side in contact with the lid material of the partition material film 20 and / or on the surface layer on the side in contact with the bottom material, and between the lid material film 10 and the bottom material film 30, respectively. Gives easy peel. The EP layer may be formed on either of the films to be bonded. For example, when the EP layer is disposed on the side of the partition material film 20 in the lid material film 10, the lid material film 10 of the partition material film 20. There is no need to form an EP layer on the side.
Further, EP layers may be arranged on both sides of the surface layer of the partition material film 20, and in this case, it is not necessary to form an EP layer on the partition material film 20 side of the lid material film 10 and the bottom material film 30. On the contrary, when EP layers are arranged on the partition material film 20 side surface layer of the lid material film 10 and the partition material film 20 side surface layer of the bottom material film 30, EP is provided on both surface layers of the partition material film 20. It is preferable to form a sealing layer without forming a layer.
In addition, the sealing layer demonstrated below is formed in the surface layer of the other party film adhere | attached with EP layer.

  The resin constituting the EP layer is not particularly limited as long as it has an easy peel function, and a mixture of two incompatible polyolefin resins can be used. For example, a mixture of linear low density polyethylene (LLDPE) and polybutene (PB), a mixture of ethylene-vinyl acetate copolymer (EVA) and polypropylene (PP), a mixture of PP and low density polyethylene (LDPE), PP and Examples include mixing of ionomer (IO), mixing of PP and ethylene-acrylic acid copolymer (EAA), mixing of PP and ethylene-methyl methacrylate copolymer (EMMA), and the like. Among them, a mixture of LLDPE and PB or a mixture of PP and LDPE can be preferably used.

The EP layer thickness is 2 μm or more, preferably 3 μm or more, more preferably 4 μm or more, and 15 μm or less, preferably 12 μm or less, more preferably 10 μm or less, from the viewpoint of film formability and peel appearance. desirable.
When the EP layer thickness is 2 μm or more, stable film-forming properties can be obtained, and when the EP layer thickness is 15 μm or less, fluffing and film residue hardly occur at the time of peeling, and a good peeling appearance can be obtained.

  The easy peel strength (peel strength) of the EP layer may be any strength as long as cohesive failure occurs in the peel and the peel surface is not fluffed. For example, at 25 ° C., preferably 1 N / 15 mm width or more, more preferably It is 2N / 15mm width or more, more preferably 4N / 15mm width or more, preferably 15N / 15mm width or less, more preferably 12N / 15mm width or less, and further preferably 10N / 15mm width or less.

  In addition, it is preferable to set the peel strength between the partition material film 20 and the bottom material film 30 to be larger than the peel strength between the lid material film 10 and the partition material film 20. From this viewpoint, the peel strength between the lid material film 10 and the partition material film 20 is preferably 1 N / 15 mm width or more and 8 N / 15 mm width or less, and the peel strength between the partition material film 20 and the bottom material film 30 is 4 N / 15 mm width. The width is preferably 15 N / 15 mm or less.

The partition material film 20 may have a sealing layer, an adhesive resin layer, and a PP layer in addition to the gas barrier layer and the easy peeling layer described above.
(Sealable layer (PE layer))
When the EP layer is not formed on the surface layer of the partition material film 20, a sealing layer is provided. For example, when the EP layer is formed on the partition material film 20 side surface of the lid material film 10, a sealing layer is formed on the lid material film 10 side surface of the partition material film 20. Thereby, an easy peel property can be imparted between the EP layer and the sealing layer.
As the sealing layer, a polyethylene resin (PE) can be used, and the type thereof is not limited. For example, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) , Ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-acrylic acid copolymer (EAA), ethyl-methyl acrylate copolymer (EMA), ethylene-methyl methacrylate copolymer A polymer (EMMA), an ethylene ionomer resin, or a mixture thereof can be used. Of these, LDPE and LLDPE are preferred from the viewpoint of versatility and economy.
The thickness of the sealing layer is preferably 5 μm or more, more preferably 10 μm or more, preferably 50 μm or less, more preferably 40 μm or less.

(Adhesive resin layer)
In the partition material film 20, an adhesive resin layer can be provided between layers having weak affinity. For example, an adhesive resin layer can be provided between the EVOH layer and the sealing layer, between the polyamide resin layer and the sealing layer, between the polyamide resin layer and the polypropylene resin (PP) layer, and the like. As the adhesive resin, it is preferable to use a polyethylene-based adhesive resin in terms of interlayer adhesion.
1-20 micrometers is preferable and, as for the thickness of an adhesive resin layer, 3-10 micrometers is more preferable.

(Polypropylene resin layer (PP layer))
The partition material film 20 may include a polypropylene resin layer (PP layer). By providing the PP layer, the partition film 20 can be given hardness. Examples of the polypropylene resin used for the PP layer include homopolypropylene, random copolymers or block copolymers with α-olefins such as ethylene. From the viewpoint of improving the transparency of the partition material film, a propylene-ethylene random copolymer is preferable.
The thickness of the PP layer is preferably 5 μm or more, more preferably 10 μm or more, preferably 50 μm or less, more preferably 40 μm or less.

  FIG. 3 shows a typical layer structure of the partition material film 20. The upper side of FIG. 3 is the lid film 10 side, and the lower side of the page is the bottom film 30 side. From the lid material film 10 side, the sealing layer 22 / adhesive resin layer 24 / polyamide resin layer 26 / EVOH layer 28 / polyamide resin layer 26 / adhesive resin layer 24 / sealing layer 22 / EP layer 23 are arranged in this order. ing.

  As a specific layer structure of the partition material film 20, the following layer structure can be mentioned, for example. In the following, the sealing resin layer is “PE”, the adhesive resin layer is “AD”, the easy peel layer is “EP”, the polyamide resin layer is “Ny”, and the ethylene-vinyl acetate copolymer saponified layer is “EVOH”. ", The polypropylene resin layer is indicated as" PP ". Further, “/” is indicated between the layers of coextrusion.

PE / AD / EVOH / AD / PE / EP,
PE / AD / Ny / EVOH / AD / PE / EP,
PE / AD / EVOH / Ny / AD / PE / EP,
PE / AD / Ny / EVOH / Ny / AD / PE / EP,
PE / AD / EVOH / AD / PP / EP,
PE / PP / AD / Ny / EVOH / AD / PE / EP,
PE / AD / EVOH / Ny / AD / PE / EP,
PE / AD / Ny / EVOH / Ny / AD / PE / EP,
PE / PP / AD / Ny / EVOH / Ny / AD / PP / EP,
PE / AD / Ny / AD / PE / EP,
PE / AD / Ny / AD / PP / EP,
PE / AD / Ny / AD / Ny / AD / PE / EP,
PE / PP / AD / Ny / AD / PP / EP,
PE / PP / AD / Ny / AD / PP / EP,
Moreover, the partition material film 20 may have layers other than the layer demonstrated above in each layer in the range which does not prevent the effect of this invention.

  The haze of the partition material film 20 is preferably 20% or less, more preferably 15% or less, and still more preferably 10% or less in haze (haze value) measured based on JIS K 7136.

  The film of the present invention can be produced using a known method. For example, an extrusion lamination method, a coextrusion inflation method, a coextrusion T die method, and the like can be used, and it is particularly preferable to use a coextrusion T die method.

<Bottom material film 30>
The bottom material film 30 is formed by deep drawing, and includes a bottom surface 32, a side wall 34 erected from the outer periphery of the bottom surface 32, and a flange portion 36 formed at an end portion of the side wall 34 in the erection direction. . The flange portion 36 of the bottom material film 30 is heat-sealed by overlapping the outer peripheral end portion of the partition material film 20 and the outer peripheral end portion 10 of the lid material film 10 thereon.
In FIG. 1, a bottom film 30 having a substantially rectangular parallelepiped deep drawing portion is illustrated, but the shape of the deep drawing is not limited thereto, and may be, for example, a substantially cubic shape, or a bottom surface. A cylindrical shape in which 32 is a circle or an ellipse may be used. Further, in the illustrated embodiment, the side wall 34 stands upright, but the side wall 34 may be inclined and upright, and the opening on the lid side is larger than the bottom surface 32 or has a truncated cone shape or a cut-off shape. A pyramid shape may be used.
In addition, a plurality of ribs that protrude toward the housing portion may be provided on the bottom surface 32 and / or the side wall 34 in order to impart (stiffen) rigid properties to the bottom material.

  The loop stiffness of the bottom material film 30 is preferably 80 g or more and 1000 g or less, more preferably 100 g or more and 700 g or less, and particularly preferably 120 g or more and 540 g or less. Since each storage part of the multistage package 100 is narrower than that of a single-stage package, the bottom material needs to be strong to secure the capacity of the storage part.

The loop stiffness can be measured using a loop stiffness tester manufactured by Toyo Seiki Seisakusho. The measurement method is shown in FIG.
The ends of the bottom film 30 cut into a strip shape having a width of 15 mm and a length of 120 mm are put together and sandwiched between the ends by a jig 62, and a loop having a loop length of 80 mm as shown in FIG. This occurs when the indenter 64 is crushed vertically by 6 mm in the direction of the arrow shown in FIG. 4 at a speed of 3.3 mm / sec. The resistance load (g) of the film was measured.

If the bottom film 30 satisfies the above-mentioned loop stiffness range and has strength as a deep-drawn molded article, the layer structure is not particularly limited. For example, when a plurality of single-layer films are laminated, coextrusion When it consists only of a film, the case where a single layer film and a coextruded film are laminated | stacked is mentioned. The configuration comprising the coextruded multilayer film is preferable because the number of steps for producing the bottom film can be reduced.
In the case of laminating a single layer film and a coextruded film, a configuration (APET // coextruded film) in which an APET film is dry laminated on the bottom side of the coextruded multilayer film is exemplified.

  The coextruded film constituting the bottom material film 30 may have, for example, the gas barrier layer, the easily peelable layer, the adhesive resin layer, and the sealing layer described in the above partition material film. In the case where the bottom material film 30 is composed only of a coextruded film, it is preferable to arrange an APET layer on the bottom side of the coextruded film because the film can be given rigidity, strength, and gloss. Further, if a PETG layer is arranged further on the bottom side of the APET layer, further gloss can be imparted.

(PETG layer)
The bottom material film 30 is provided with a layer made of a polyethylene terephthalate glycol (PETG) resin, whereby good waist, gloss and transparency can be obtained.
PETG resin refers to a polyester resin in which 5 mol% or more of 1,4-cyclohexanedimethanol component is contained in 100 mol% of a polyhydric alcohol component. The lower limit of the content of the 1.4-cyclohexanedimethanol component is preferably 10 mol% or more, more preferably 12 mol% or more, and even more preferably 15 mol% or more from the viewpoint of increasing the degree of non-crystallization. The upper limit is preferably 50 mol% or less, more preferably 47 mol% or less, and still more preferably 45 mol% or less, from the viewpoint of obtaining sufficient impact strength of the film.

  The lower limit of the ethylene terephthalate unit content in 100 mol% of the unit constituting the polyester resin of the PETG layer is preferably 50 mol% or more, from the viewpoint of film rigidity, tear resistance, impact strength, heat resistance, etc. % Or more is more preferable, and 60 mol% or more is still more preferable. Therefore, the terephthalic acid component in 100 mol% of the polyvalent carboxylic acid component is 50 mol% or more, the ethylene glycol component in 50 mol% of the polyhydric alcohol component in 100 mol%, further 55 to 90 mol%, especially 60 It is preferable to contain -88 mol%.

Resins other than the ethylene terephthalate unit constituting the PETG layer can be combined using the following polyvalent carboxylic acid component and polyhydric alcohol component. Examples of the polyvalent carboxylic acid component include terephthalic acid constituting the ethylene terephthalate unit, aromatic dicarboxylic acid, aliphatic dicarboxylic acid, and alicyclic dicarboxylic acid. Examples of the aromatic dicarboxylic acid include the following.
Benzenedicarboxylic acids such as isophthalic acid, orthophthalic acid, 5-tert-butylisophthalic acid,
・ Naphthalenedicarboxylic acids such as 2,6-naphthalenedicarboxylic acid,
-Dicarboxybiphenyls such as 4,4'-dicarboxydiphenyl, 2,2,6,6-tetramethylbiphenyl-4,4'-dicarboxylic acid,
1,1,3-trimethyl-3-phenylindene-4,5-dicarboxylic acid and its substituted product,
1,2-diphenoxyethane-4,4′-dicarboxylic acid and its substitutes,

Aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, pimelic acid, suberic acid, undecanoic acid, dodecanedicarboxylic acid, brassic acid, tetradecanedicarboxylic acid, tapsinic acid , Nonadecane dicarboxylic acid, docosane dicarboxylic acid and the like.
Examples of the alicyclic dicarboxylic acid include 1,4-dicarboxycyclohexane and 1,3-dicarboxycyclohexane.

Examples of the polyhydric alcohol component include aliphatic diols, alicyclic diols, aromatic diols, and polyalkylene glycols in addition to ethylene glycol constituting the polyethylene terephthalate unit. Specific examples include the following components.
As the aliphatic diol, diethylene glycol, propylene glycol, butanediol, 1,6-hexanediol, 1,10-decanediol, neopentyl glycol, 2-methyl-2-ethyl-1,3-propanediol, 2,2 -Diethyl-1,3-propanediol, 2-ethyl-2-n-butyl-1,3-propanediol and the like.
-As an alicyclic diol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol and the like.
・ As aromatic diols, ethylene oxide adducts of bisphenol compounds such as 2,2-bis (4′-β-hydroxyethoxydiphenyl) propane and bis (4′-β-hydroxyethoxyphenyl) sulfone, and xylylene glycol Such.
-Polyalkylene glycols such as polyethylene glycol and polypropylene glycol.

  For the PETG layer of the film of the present invention, it is preferable to use a polyethylene terephthalate resin in which the polyhydric alcohol component is composed of 1,4-cyclohexanedimethanol and diethylene glycol and the polyvalent carboxylic acid component is terephthalic acid.

  The thickness of the PETG layer is preferably 2 μm or more and 20 μm or less, more preferably 3 μm or more and 17 μm or less, and even more preferably 4 μm or more and 15 μm or less from the viewpoint of the rigid property (waist) of the film.

(APET layer)
By arranging the APET layer, the bottom material film 30 can impart rigidity, strength, and moldability to the film. The APET layer is a layer obtained by forming the PET shown below by quenching to form a film while inhibiting crystallization.
As PET, the ethylene terephthalate unit ratio in the whole resin is generally 80 mol% or more, preferably 83 mol% or more, and more preferably 85 mol% or more. The PET can be formed of a polyvalent carboxylic acid component and a polyhydric alcohol component described below.
Examples of the polyvalent carboxylic acid component include aromatic dicarboxylic acid, aliphatic dicarboxylic acid and alicyclic dicarboxylic acid in addition to terephthalic acid constituting the ethylene terephthalate unit. Examples of the aromatic dicarboxylic acid include the following.
Benzenedicarboxylic acids such as isophthalic acid, orthophthalic acid, 5-tert-butylisophthalic acid,
・ Naphthalenedicarboxylic acids such as 2,6-naphthalenedicarboxylic acid,
-Dicarboxybiphenyls such as 4,4'-dicarboxydiphenyl, 2,2,6,6-tetramethylbiphenyl-4,4'-dicarboxylic acid,
1,1,3-trimethyl-3-phenylindene-4,5-dicarboxylic acid and its substituted product,
1,2-diphenoxyethane-4,4′-dicarboxylic acid and its substitutes,

Aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, pimelic acid, suberic acid, undecanoic acid, dodecanedicarboxylic acid, brassic acid, tetradecanedicarboxylic acid, tapsinic acid , Nonadecane dicarboxylic acid, docosane dicarboxylic acid and the like.
Examples of the alicyclic dicarboxylic acid include 1,4-dicarboxycyclohexane and 1,3-dicarboxycyclohexane.

Examples of the polyhydric alcohol component include aliphatic diols, alicyclic diols, aromatic diols, and polyalkylene glycols in addition to ethylene glycol constituting the polyethylene terephthalate unit. Specific examples include the following components.
As the aliphatic diol, diethylene glycol, propylene glycol, butanediol, 1,6-hexanediol, 1,10-decanediol, neopentyl glycol, 2-methyl-2-ethyl-1,3-propanediol, 2,2 -Diethyl-1,3-propanediol, 2-ethyl-2-n-butyl-1,3-propanediol and the like.
-As an alicyclic diol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol and the like.
・ As aromatic diols, ethylene oxide adducts of bisphenol compounds such as 2,2-bis (4′-β-hydroxyethoxydiphenyl) propane and bis (4′-β-hydroxyethoxyphenyl) sulfone, and xylylene glycol Such.
-Polyalkylene glycols such as polyethylene glycol and polypropylene glycol.

The polyvalent carboxylic acid component and / or the polyhydric alcohol component is preferably used in an appropriate combination of two or more types of monomers and content ratios in order to improve the properties and economical efficiency as a deep-drawing coextruded film.
The resin constituting the PET layer may be any of a single copolymer, two or more types of copolymers, or a mixture of homopolymers.

The thickness of the APET layer is preferably 30 μm or more and 200 μm or less, more preferably 35 μm or more and 190 μm or less, and even more preferably 40 μm or more and 180 μm or less, from the viewpoint of the rigid property (waist) of the film.
The ratio of the total thickness of the PETG layer and the APET layer to the total film thickness is preferably 60% or more and 95% or less, more preferably 70% or more and 95% or less, from the viewpoint of the rigid property and film forming property of the film. % To 95% is more preferable.

Moreover, as above-mentioned, the base material film 30 can also be set as the structure which laminated | stacked other single layer films on the bottom side of a co-extrusion multilayer film, when laminating | stacking a several single layer film. In that case, in terms of deep drawability and bottom material strength, it is preferable to use an APET film as the bottom monolayer film.
As an adhesive used for dry lamination, a two-component curable urethane-based adhesive or the like can be used.

Below, the specific layer structure of a bottom material film is shown. Note that “//” indicates a dry laminate layer, and an adhesive layer of the dry laminate is omitted.
APET // PE
APET // EVOH // PE
APET // EVOH / Ny / AD / PE,
APET // PE / AD / EVOH / AD / PE,
APET // PE / AD / Ny / EVOH / Ny / AD / PE,
APET / AD / EVOH / Ny / AD / PE,
APET / AD / Ny / EVOH / Ny / AD / PE,
PETG / APET / AD / NyEVOH / Ny / AD / PE,
PETG / APET / AD / Ny / EVOH / Ny / AD / PE,

<Cover material film 10>
The lid material film 10 is a flat film, and is heat-sealed by overlapping the outer peripheral end portion thereof, the outer peripheral end portion of the partitioning material film 20, and the flange portion 36 of the bottom material film 30.

The lid material film 10 includes a case where a plurality of single films are laminated, a case where the lid film 10 is composed of only a coextruded multilayer film, and a case where a single layer film and a coextruded multilayer film are laminated. A structure comprising a co-extruded multilayer film is preferable because it can reduce the step of producing a lid film. In addition, when a single layer film is used for the lid film, there are advantages such as printing on the single layer film, and using a film with tension on the single layer film to improve the appearance of the lid material. is there. Among them, it is preferable to dry laminate a biaxially stretched polyethylene terephthalate film (o-PET) on the outside as a lid material of the coextruded multilayer film.
The coextruded film constituting the lid material film 10 may have the gas barrier layer, the adhesive resin layer, the sealing layer, and the easy peeling layer described in the partition material film 20.
As an adhesive used for dry lamination, a two-component curable urethane adhesive is used.

Below, the preferable example of a layer structure of a cover material film is shown.
o-PET // EVOH / Ny / AD / LLDPE / EP

Examples of the present invention will be described below, but the present invention is not limited thereto.

<Raw material for co-extruded multilayer film>
(Raw material for co-extruded multilayer film)
PETG: PETG manufactured by Eastman Chemical Company, intrinsic viscosity 0.78 dl / g,
APET: polyethylene terephthalate resin, intrinsic viscosity 0.82 dl / g,
Ny: 6-66 nylon copolymer, nylon 66 ratio 15% by mass,
EVOH: saponified ethylene-vinyl acetate copolymer, ethylene 32 mol, saponification degree 95 mol% or more,
PE: linear low density polyethylene, melting point 123 ° C., density 0.920, MFR 2.1 g / 10 minutes,
PP: polypropylene-ethylene random copolymer, MFR 2.5 g / 10 min,
LLDPE: linear low density polyethylene resin, melting point 125 ° C., density 0.920, MFR 2.1 g / 10 min.
AD: unsaturated carboxylic acid-modified polyethylene resin,
EP: Mixing of linear low density polyethylene (60% by mass) and polybutene (40% by mass)

<Preparation of lid film>
A coextruded multilayer film having the following layer structure was produced by the coextrusion T-die method.
EVOH (10 μm) / Ny (10 μm) / AD (5 μm) / LLDPE (20 μm) / EP (5 μm)
A biaxially stretched polyethylene terephthalate film (12 μm) was dry-laminated using a two-component mixed urethane adhesive on the EVOH layer surface of the coextruded multilayer film to prepare a lid material film A-1.

<Preparation of partition material film and bottom material film>
By the coextrusion T-die method, a partition material film having a layer structure shown in Table 1 below and a bottom material film shown in Table 2 were prepared. In the column of the layer configuration, the thickness (μm) of each layer is described in parentheses after each layer.

In addition, in B-15, each film shown below was produced by dry laminating using a two-component mixed urethane adhesive as an adhesive.
PE (30): Mitsui Chemicals Tosero Co., Ltd. U. X HC, 30 μm thick,
SPR (15): manufactured by Mitsubishi Plastics, Super Neal SPR-P, 15 μm thick,
EP (30): Jfilm, IMX, 30 μm thick

Moreover, in C-1 to C-4, a single layer film (APET) shown below is used, a two-component mixed urethane adhesive is used as an adhesive, and a coextruded film or the following single layer film ( PE (50)) and dry laminated.
APET: manufactured by Mitsubishi Chemical Corporation, Nova Clear (170-250 μm thick)
PE (50): Mitsui Chemicals Tosero Co., Ltd. U. X HC (50μm thickness)

<Production of multi-stage (two-stage) packaging>
Using the deep-drawing packaging machine (FV6300, manufactured by Omori Machine Industry Co., Ltd.), the produced bottom material film was 160 mm long, 120 mm wide, and 20 mm deep under the conditions of a deep drawing temperature of 100 ° C. and a molding heating time of 2 seconds. Deep squeeze-molded into a shape, and sliced ham (diameter of about 90 mm / sheet, thickness of about 1 mm / sheet, total of 6 sheets, total of about 50 g) was shifted in the horizontal direction by about 5 mm per sheet and stacked. A thing was put and the partition material film was covered on it (corresponding to the lower storage part).
Subsequently, the same sliced ham as described above was placed on the partition material film, and a lid material film was placed thereon (corresponding to the upper storage portion).
Finally, the bottom film, partition film, and lid film together are frame sealed on four sides under conditions of a seal width of 7 mm, a seal temperature of 135 ° C., and a seal time of 2.5 seconds, and multi-stage (two-stage) packaging The body was made.

  The following evaluation was performed on the produced two-stage package. The evaluation results are summarized in Table 3.

(Partition material film hanging down)
In the produced multistage package, it was evaluated according to the following criteria whether or not the partition material film hangs down moderately with the weight of the sliced ham accommodated in the upper stage and the lid material film swells with the thickness of the sliced ham in the upper stage accommodating part.
The bulge of the lid material is 5 mm or less: ○,
The bulge of the lid material exceeds 5 mm: x,
Note that the bulging of the lid material is obtained by measuring the displacement of the seal portion in the vertical upward direction with respect to the lid material surface in a state where the two-stage package body is placed on a horizontal surface with the bottom surface down.
In Comparative Example 2, wrinkles occurred in the seal portion due to the fact that the partition material film was as thin as 35 μm.

(Rigidity of deep-drawn bottom material)
In the produced multi-stage package, the package body is bent when the package body is lifted horizontally by holding the distance position 72 divided into three equal parts of the package body from the upper and lower sides of the package body from one place 74 at the four corners. The case where it was not carried out was marked with “◯”, and the case where the unwrapped portion of the package was bent downward due to its own weight was designated as “x”. FIG. 5 is a view of the package body as viewed from the direction of the lid, and shows a position 72. Moreover, the specific example in case evaluation is "x" is shown to Fig.6 (a)-(c). (A) is an obliquely upward direction, (b) is a lateral direction, and (c) is an oblique view.

DESCRIPTION OF SYMBOLS 10 Cover material film 20 Partition material film 30 Bottom material film 32 Bottom part 34 Side wall 36 Flange part 42 Upper stage accommodating part 44 Lower stage accommodating part 100 Multistage package

Claims (8)

A lid material film, at least one partition material film, and a bottom material film;
The bottom film is provided with a bottom surface, a side wall erected from the outer periphery of the bottom surface, and a flange portion formed at an end of the side wall in the erection direction;
The partition material film used in a multistage package having a housing portion between the respective films, wherein the tensile elastic modulus is 200 MPa or more and 1000 MPa or less, and the thickness is 40 μm or more and 200 μm or less, and is a coextruded multilayer film. , Partitioning film.   The partition material film according to claim 1, wherein the partition material film includes a gas barrier layer and an easily peelable layer. A lid material film, at least one partition material film, and a bottom material film;
The bottom film is provided with a bottom surface, a side wall erected from the outer periphery of the bottom surface, and a flange portion formed at an end of the side wall in the erection direction;
A multi-stage package having a housing portion between the respective films,
The multistage package, wherein the partition material film is the partition material film according to claim 1.   The multistage package according to claim 3, wherein the bottom film has a loop stiffness of 80 g or more and 1000 g or less.   The multi-stage package according to claim 3 or 4, wherein each of the lid material film and the bottom material film includes a coextruded multilayer film layer. The oxygen permeability of the lid material film, the partition material film, and the bottom material film are all from 0.1 cc / m ² / day / atm to 50 cc / m ² / day / atm. The multistage package according to any one of 5. The partition material film side surface layer in the lid material film, or the lid material film side surface layer in the partition material film is an easily peelable layer,
The peel strength between the lid material film and the partition material film is 1 N / 15 mm width or more and 15 N / 15 mm width or less,
The bottom material film side surface layer in the partition material film, or the partition material film side surface layer in the bottom material film is an easily peelable layer,
The multistage package according to any one of claims 3 to 6, wherein a peel strength between the partition material film and the bottom material film is 1 N / 15 mm width or more and 15 N / 15 mm width or less.   The multistage package according to any one of claims 3 to 7, wherein a peel strength between the partition material film and the bottom material film is larger than a peel strength between the lid material film and the partition material film.