JP2007008046A - Film for deep drawing, bottom material for deep drawing packaging and deep drawing packaging - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film for deep drawing which shows good microwave oven opening properties, boiling resistance at a temperature lower than 100°C and easy peelability. <P>SOLUTION: The film has at least a polyamide resin layer and an easily peelable layer having an easy peel strength of 1.96 to 7.84 N/15 mm at 25°C and 0.8 to 4.90 N/15 mm at 95°C and showing cohesive failure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention mainly relates to a deep drawing film, a bottom material for a deep drawing package, and a deep drawing package that can be suitably used for packaging foods heated in a microwave together with the package.

  Conventionally, as a package for foods that are heated or cooked in a microwave oven, there is a wide variety of packages in which a part of the package is opened and then heat-treated in a microwave oven before being heated in the microwave oven. It has been commonly used. The reason for this is that if heat treatment is performed in a microwave oven without opening, there is a risk that the internal pressure in the package rises and bursts during heating, and the internal pressure is released outside the package in order to avoid the risk. However, in the case of a conventional package, it takes time to open a part of the package before heat treatment in a microwave oven, and internal pressure escapes to the outside during heating, and the package may expand. Therefore, there is a problem that it is difficult to understand the completion of heating of the contents.

In order to solve the above problems, recently, a heat-sealed part of a package or a part with weak heat-seal strength is prepared, and heat treatment is performed in a microwave oven without opening the package. A package that has been devised to release the internal pressure by peeling off a portion having a weak seal strength has also been developed (for example, Patent Document 1). However, in order to make such a package, there was a problem that a special film corresponding to the heat seal part of the packaging machine had to be used. Furthermore, since the package includes only a type that cannot be boiled, assuming only heating by a microwave oven, when such a package is used, there is a problem that the cooking method is limited. there were.
Japanese Patent Laid-Open No. 11-139465

  The present invention is intended to solve the above-mentioned problems of the prior art, and the object of the present invention is that no special device is required for the heat seal part, and it does not rupture due to an increase in internal pressure when heated in a microwave oven. Another object of the present invention is to provide a deep-drawing film capable of releasing the internal pressure by peeling off the easy peel portion and further capable of boiling heating below 100 ° C.

  Another object of the present invention is to provide a bottom material for a deep-drawn package and a deep-drawn package comprising the deep-drawing film of the present invention.

  The object of the present invention is a polyamide resin (hereinafter sometimes referred to as “PA”) layer, a 1.96 N / 15 mm width to 7.84 N / 15 mm width at 25 ° C., and a 0.8 N / 15 mm width at 95 ° C. This is achieved by a film for deep drawing having at least an easy peel layer (hereinafter sometimes referred to as “EP layer”) having an easy peel strength of 4.90 N / 15 mm width or less and having cohesive failure. .

  Here, having a cohesive fracture property means that when the deep-drawn package is opened, the easy peel layer itself is broken and peeled off, and the easy peel layer remains on both the bottom material side and the lid material side. .

The EP layer has an easy peel strength of 1.96 N / 15 mm width to 7.84 N / 15 mm width at 25 ° C. and 0.8 N / 15 mm width to 4.90 N / 15 mm width at 95 ° C. The resin constituting the EP layer is not particularly limited, but is composed of a mixture of the resin A and the resin B, and the contents of the resins A and B are 40% by mass to 80% by mass and 20% by mass to 60% by mass, respectively. % Or less is preferable.
Resin A: linear low density polyethylene resin (hereinafter sometimes referred to as “LLDPE”), ethylene-vinyl acetate copolymer resin (hereinafter sometimes referred to as “EVA”), ethylene-acrylic acid copolymer Copolymer resin (EAA), ethylene-ethyl acrylate copolymer resin (EEA), ethylene-methacrylic acid copolymer resin (EMAA), ethylene-methyl methacrylate copolymer resin (EMMA), ethylene-methyl acrylate copolymer At least one selected from the group consisting of a polymer resin (EMA) and these ionomers Resin B: Polypropylene resin (hereinafter sometimes referred to as “PP”) or polybutene resin (hereinafter sometimes referred to as “PB”). )

  The film of the present invention preferably has at least one PP layer outside the PA layer and / or between the PA layer and the EP layer.

  Further, the film of the present invention has at least one EVA layer or polyethylene resin (hereinafter referred to as “PE”) between the PA resin layer and the EP layer or / and between the PA layer and the PP layer. It is preferable to have a layer.

  The film of the present invention preferably has at least one adhesive resin layer between the PA layer and the EP layer or / and between the PA layer and the PP layer.

  In addition, the film of the present invention has at least one saponified ethylene-vinyl acetate copolymer (hereinafter referred to as “EVOH”) between the PA layer and the EP layer or / and between the PA layer and the PP layer. It is preferable that it has.

  The second aspect of the present invention is a bottom material for a deep drawn package formed by the deep drawing film described above.

  The third aspect of the present invention is a deep drawn package using the above bottom material. The deep-drawn package is preferably provided for use in microwave heating.

  The film for deep drawing of the present invention comprises a polyamide resin (PA) layer, 1.96 N / 15 mm width to 7.84 N / 15 mm width at 25 ° C., and 0.8 N / 15 mm width to 4.90 N / 15 mm at 95 ° C. It has at least an easy peel layer (EP layer) exhibiting an easy peel strength equal to or less than the width and having cohesive failure. With this configuration, according to the present invention, it is possible to obtain an optimum film for deep drawing having a microwave oven opening property, a boil resistance of less than 100 ° C., and a good easy peel property.

  Since the film of the present invention is a film having good microwave oven opening property, boil resistance of less than 100 ° C. and easy peel property, it is particularly suitable as a film for microwave oven-compatible deep drawing packages. It can be suitably used as a bottom material.

  Hereinafter, the film for deep drawing, the bottom material for a deep drawing package, and the deep drawing package of the present invention will be described in more detail.

[Film for deep drawing]
The film of the present invention comprises a polyamide resin (PA) layer and a range of 1.96 N / 15 mm width to 7.84 N / 15 mm width at 25 ° C., and 0.8 N / 15 mm width to 4.90 N / 15 mm width at 95 ° C. It has at least an easy peel layer (EP layer) having an easy peel strength and cohesive failure.

(PA layer)
In the film of the present invention, it is necessary to provide at least one PA layer for the purpose of imparting pinhole resistance and deep drawability.

  The type of resin constituting the PA layer is not particularly limited as long as it is a polyamide resin, but it is preferable to use a nylon resin (Ny) from the viewpoint of pinhole resistance. Examples of Ny include polymers of condensed 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, or two of these. Copolymers with the above, and mixtures thereof can also be mentioned. Among them, it is preferable to use 6 nylon or 6-66 nylon.

  The thickness of the PA layer is 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, and is 200 μm or less, preferably 180 μm or less, more preferably 150 μm or less. When the lower limit value of the thickness of the PA layer is 5 μm, good pinhole resistance can be obtained, and when the upper limit value is 200 μm, the thermoformability of the film can be maintained well.

  The film of this invention should just have at least one PA layer, and may form two or more layers as needed. If there are two or more PA layers in the film of the present invention, the pinhole resistance and water resistance can be further improved, and the whitening prevention effect of the EVOH layer can be further improved. When two or more PA layers are formed in the film, the total thickness of the PA layers is desirably 5 μm to 200 μm, preferably 10 μm to 180 μm.

  (Easy peel layer (EP layer))

  The film of the present invention has an easy peel having an innermost layer of 1.96 N / 15 mm width to 7.84 N / 15 mm width at 25 ° C. and 0.8 N / 15 mm width to 4.90 N / 15 mm width at 95 ° C. It is necessary to provide an EP layer that exhibits strength and has cohesive failure.

  The easy peel strength at 25 ° C. of the EP layer is 1.96 N / 15 mm width or more, preferably 2.45 N / 15 mm width or more, more preferably 2.94 N / 15 mm width or more, and 7.84 N / 15 mm width or less, preferably Is preferably 7.35 N / 15 mm width or less, more preferably 6.86 N / 15 mm width or less.

  By setting the easy peel strength at 25 ° C. of the EP layer to 1.96 N / 15 mm width or more, it is possible to obtain the resistance to breakage during transportation, and by opening it to 7.84 N / 15 mm width or less, good opening Sex can be obtained. The easy peel strength at 95 ° C. of the EP layer is 0.8 N / 15 mm width or more, preferably 0.98 N / 15 mm width or more, more preferably 1.47 N / 15 mm width or more, and 4.90 N / 15 mm width or less, preferably Is preferably 4.41 N / 15 mm width or less, more preferably 3.92 N / 15 mm width or less.

  Further, by setting the easy peel strength at 95 ° C. of the EP layer to 0.8 N / 15 mm width or more, it is possible to withstand boil heating of less than 100 ° C., and by setting it to 4.90 N / 15 mm width or less, microwave heating Sometimes the package can be opened smoothly with internal pressure without bursting.

  The resin constituting the EP layer has an easy peel strength of 1.96 N / 15 mm width to 7.84 N / 15 mm width at 25 ° C. and 0.8 N / 15 mm width to 4.90 N / 15 mm width at 95 ° C. And if it is resin which has cohesive failure, it will not specifically limit. The EP layer can be composed of, for example, the following different types of resins A and B.

That is, as the resin A, the main component is a linear low density polyethylene (LLDPE) having a melting point of 90 ° C. or higher, preferably a melting point of 95 ° C. or higher, more preferably a melting point of 100 ° C. or higher, most preferably a melting point of 120 ° C. or higher.
Low density polyethylene (LDPE),
Ethylene-vinyl acetate copolymer (EVA),
Ethylene-acrylic acid copolymer (EAA),
Ethylene-ethyl acrylate copolymer (EEA),
Ethylene-methacrylic acid copolymer (EMAA),
Ethylene-methyl methacrylate copolymer (EMMA),
Ethylene-methyl acrylate copolymer (EMA)
And at least one selected from the group consisting of these ionomers can be used. From the viewpoint of heat resistance, it is preferable to use a linear low-density polyethylene resin (LLDPE) having a melting point of 100 ° C. or higher and a density of 0.915 g / cm ³ or more and 0.945 g / cm ³ or less. it can. Furthermore, from the viewpoint of heat resistance and low temperature sealing properties, a mixed resin of a linear low density polyethylene resin (LLDPE) and an ethylene-vinyl acetate copolymer (EVA) can be suitably used.

On the other hand, as the resin B,
Polypropylene (PP) or polybutene (PB)
Can be used. As the PP of the resin B, any of a random copolymer (including a random copolymer obtained by a metallocene catalyst), a homopolymer, a block copolymer, and the like can be used, and among these, a random copolymer can be preferably used. Examples of polybutene (PB) include 1-polybutene and 2-polybutene, and 1-polybutene can be particularly preferably used.

  The content of the resin A in the resin constituting the EP layer is 40% by mass or more, preferably 50% by mass or more, more preferably 55% by mass or more, and 80% by mass or less, preferably 70% by mass or less. More preferably, the content is 65% by mass or less. The content of the resin B in the resin constituting the EP layer is 20% by mass or more, preferably 30% by mass or more and 35% by mass or more, and 60% by mass or less, preferably 50% by mass or less, 45% by mass. % Or less is desirable. By setting the content ratios of the resin A and the resin B within the above ranges, it is possible to keep the easy peel strength at 25 ° C. and 95 ° C. within a predetermined range defined by the present invention.

  The easy peel strength at 25 ° C. can be adjusted by changing the content ratios of Resin A and Resin B. For example, when it is desired to increase the easy peel strength at 25 ° C., it can be achieved by increasing the content of the resin A, while when it is desired to decrease the easy peel strength at 25 ° C., the content of the resin A. This can be achieved by reducing.

  The easy peel strength at 95 ° C. can be adjusted by changing the melting point and density of the resin A. For example, when it is desired to increase the easy peel strength at 95 ° C., it can be achieved by using a resin A having a relatively high melting point or a resin A having a high density. On the other hand, when it is desired to reduce the easy peel strength at 95 ° C., it can be achieved by using a resin A having a relatively low melting point (however, a melting point of 90 ° C. or higher) or a resin A having a low density.

  The thickness of the EP layer is 3 μm or more, preferably 4 μm or more, more preferably 5 μm or more, and 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less from the viewpoint of film forming property and peel appearance. It is desirable to do. By setting the thickness of the EP layer to 3 μm or more, stable film forming properties can be obtained. On the other hand, when the thickness of the EP layer is 20 μm or less, fluffing and film residue can hardly occur during peeling, and a good peel appearance can be obtained.

(Intermediate and outer layers)
In the film of the present invention, an intermediate layer can be provided between the PA layer and the EP layer, and an outer layer can be provided outside the PA layer. Here, the intermediate layer is a single layer or a layer composed of two or more layers provided between the PA layer and the EP layer, and the outer layer is a single layer or two or more layers provided outside the PA layer. A layer composed of a plurality of layers. Below, each layer which comprises an intermediate | middle layer and an outer layer is demonstrated.

-EVA layer and PE layer-
As the intermediate layer and the outer layer, an ethylene-vinyl acetate copolymer (EVA) layer or a polyethylene resin (PE) layer may be provided for the purpose of imparting flexibility. The ethylene content of EVA is not particularly limited, but from the viewpoint of film formation stability, it is 1 mol% or more, preferably 1.5 mol% or more, 20 mol% or less, more preferably 15 mol% or less. It is desirable that When the EVA layer is provided, the thickness of the EVA layer is 10 μm or more, preferably 20 μm or more, more preferably 25 μm or more, and 100 μm or less, preferably 80 μm or less, more preferably 60 μm or less from the viewpoint of film forming properties. It is desirable to do.

  Examples of commercially available EVA include a product name “Novatech EVA” manufactured by Nippon Polyethylene Co., Ltd.

  When providing a PE layer in an intermediate | middle layer and an outer layer, PE used by PE layer is not specifically limited. For example, as the PE layer, a low density polyethylene resin (LDPE), a linear low density polyethylene resin (LLDPE), a high density polyethylene (HDPE), or a blend thereof can be used. The blend ratio can be appropriately determined for the purpose of imparting desired flexibility. For example, the blending ratio of LDPE and HDPE is 40 to 80:60 to 20, preferably 50 to 80:50 to 20, more preferably by mass ratio. Preferably it can be set to 60-80: 40-20.

LDPE or LLDPE preferably has a density of 0.90 g / cm ³ or more, and HDPE preferably has a density of 0.94 g / cm ³ or more. By using a high-density material, moderate hardness can be imparted to the PE layer while maintaining flexibility. The thickness of the PE layer is 10 μm or more, preferably 20 μm or more, more preferably 25 μm or more, and 100 μm or less, preferably 80 μm or less, more preferably 60 μm or less.

  Examples of commercially available PEs include Idemitsu Petrochemical's trade name “MORETECH”.

-PP layer-
A polypropylene resin (PP) layer can also be provided for the purpose of imparting hardness to the outer layer and / or the intermediate layer. The type of PP is not particularly limited, and for example, a random copolymer (including a random copolymer obtained by a metallocene catalyst), a block copolymer, a homopolymer, or a blend thereof can be used. Particularly preferably, random copolymers can be used. Examples of commercially available PP include the product name “Novatech PP” manufactured by Nippon Polypro Co., Ltd., the product name “Noblen” manufactured by Grand Polymer Co., Ltd. and the like.

-EVOH layer-
An EVOH layer can be provided in the intermediate layer for the purpose of imparting oxygen barrier properties. The ethylene content of EVOH used in the EVOH layer is not particularly limited, but is 32 mol% or more, preferably 38 mol% or more, and 47 mol% or less, preferably 44 mol from the viewpoint of film formation stability. % Or less is desirable. Further, EVOH has a saponification degree of 90% or more, preferably 95 mol% or more. By maintaining the ethylene content and saponification degree of EVOH within the above ranges, the coextrudability of the film of the present invention and the strength of the film can be improved. Examples of commercially available EVOH include, for example, Kuraray Co., Ltd., trade name “EVAL”, Nippon Synthetic Chemical Co., Ltd., trade name “Soarnol”, and the like.

  When the EVOH layer is provided, the thickness of the EVOH layer is 5 μm or more, preferably 8 μm or more, more preferably 10 μm or more, and 30 μm or less, preferably 25 μm or less, more preferably 20 μm or less. By setting the lower limit of the EVOH layer thickness to 5 μm, sufficient oxygen barrier properties can be obtained, and by setting the upper limit to 30 μm, the coextrudability of the film is not deteriorated and good film strength is maintained. it can.

-Adhesive resin layer-
Further, in the intermediate layer and the outer layer, an adhesive resin layer can be provided for bonding the layers. The adhesive resin used in the adhesive resin layer is not particularly limited as long as the PA layer, PE layer, and PP layer can be bonded to the required strength, but a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof is preferable. Can be used. Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid and the like. In addition, an ester or anhydride of the unsaturated carboxylic acid can be used as an adhesive resin, and as derivatives, methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, butyl acrylate, butyl methacrylate, vinyl acetate. , Glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide, sodium acrylate and the like can be used. Examples of commercially available adhesive resins include Mitsui Chemical Co., Ltd., trade name “Admer”, Mitsubishi Chemical Corporation, trade name “Modic”, and these can be used preferably.

  At least one adhesive resin layer can be provided between the PA layer and the intermediate and outer layers. Furthermore, it is preferable to provide between the PE layer and PA layer of an intermediate | middle layer, or between PA layer and outer layer PP from a viewpoint of raising interlayer adhesive strength more.

  The film of the present invention can contain an additive in each layer as necessary, as long as the effects of the present invention are not impaired. Additives that can be included include crystal nucleating agents, heat stabilizers, ultraviolet absorbers, lubricants, weathering stabilizers, slip agents, antistatic agents, antifogging agents, pigments, dyes and the like. The crystal nucleating agent is not particularly limited, and a known crystal nucleating agent can be used. Examples thereof include sorbitols, metal salts such as di- (aluminum para-t-butylbenzoate) and sodium bis (4-t-butylphenyl) phosphate, and inorganic crystal nucleating agents such as silica and talc. . Of these, crystal nucleating agents of sorbitols and metal salts are preferable. The crystal nucleating agent is preferably blended in an amount of 0.05 parts by mass or more and 1.00 parts by mass or less with respect to 100 parts by mass of the resin. Furthermore, it is preferable that they are 0.05 mass part or more and 0.50 mass part or less. Here, when there are too few compounding quantities of a crystal nucleating agent, the transparency improvement effect may not be enough. On the other hand, when the compounding amount of the crystal nucleating agent is too large, it is not only economically disadvantageous, but conversely, transparency may deteriorate.

<Layer structure of film>
The layer structure of the film of the present invention is composed of a polyamide resin (PA) layer and a width of 1.96 N / 15 mm or more and 7.84 N / 15 mm or less at 25 ° C., and a width of 0.8 N / 15 mm or more and 4.90 N / 15 mm at 95 ° C. The layer configuration of the other layers is not particularly limited as long as it has at least an easy peel layer (EP layer) having an easy peel strength less than the width and cohesive failure. For example, when represented by PA layer (A), PE layer (B), EVA layer (C), PP layer (D), easy peel layer (E), adhesive resin (F) and EVOH layer (H), The layer structure can be formed. Among these, a preferable layer configuration is the following (2), (4), (8), (12) or (15), and a more preferable layer configuration is (8) or (15).
(1) A / F / E (hereinafter referred to as “layer structure (1)”)
(2) A / F / B / E (hereinafter referred to as “layer structure (2)”)
(3) A / F / C / E (hereinafter referred to as “layer structure (3)”)
(4) A / F / D / E (hereinafter referred to as “layer structure (4)”)
(5) D / F / A / F / E (hereinafter referred to as “layer structure (5)”)
(6) D / F / A / F / B / E (hereinafter referred to as “layer structure (6)”)
(7) D / F / A / F / C / E (hereinafter referred to as “layer structure (7)”)
(8) D / F / A / F / D / E (hereinafter referred to as “layer structure (8)”)
(9) A / F / A / F / E (hereinafter referred to as “layer structure (9)”)
(10) A / F / A / F / B / E (hereinafter referred to as “layer structure (10)”)
(11) A / F / A / F / C / E (hereinafter referred to as “layer structure (11)”)
(12) A / F / A / F / D / E (hereinafter referred to as “layer structure (12)”)
(13) D / F / H / A / F / B / E (hereinafter referred to as “layer structure (13)”)
(14) D / F / H / A / F / C / E (hereinafter referred to as “layer structure (14)”)
(15) D / F / H / A / F / D / E (hereinafter referred to as “layer structure (15)”)
(16) B / F / H / A / F / B / E (hereinafter referred to as “layer structure (16)”)

<Method for producing film for deep drawing>
The deep drawing film of the present invention can be produced by simultaneously or sequentially laminating a PA layer, an EP layer, an intermediate layer formed in the middle thereof, and an outer layer formed on the outer side.

  The film of the present invention can simultaneously produce a PA layer, an EP layer, an intermediate layer, and an outer layer by co-extrusion using an extruder equipped with a die by an existing method such as a T-die method or a tubular method. . Further, the deep drawing film can be sequentially produced by separately forming the resin constituting each layer and then laminating them using a press method, a roll nip method or the like.

[Bottom material for deep-drawn packaging and deep-drawn packaging]
The film of the present invention can be used in a deep-drawn package by filling with contents such as hamburger after deep-drawing, and covering and heat-sealing a cover material film thereon. In particular, when the film of the present invention is used as the bottom material of a deep drawn package, a good deep drawn package can be obtained. Specifically, the film of the present invention is formed on the bottom material of a deep drawn package by a deep drawn packaging machine.

  FIG. 1 is an explanatory view showing a package before joining. Contents 40 such as pasta are accommodated in the recess 30 of the bottom member 20. FIG. 2 is an explanatory view showing the package after joining the lid and the bottom material. The upper surface of the flange portion 25 of the bottom member 20 and the portion around the lower surface of the lid member 10 are heat sealed to form a heat seal portion 50 (shaded in the figure).

  The cover of the deep-drawn package of the present invention is capable of heat sealing the composite film of the present invention, and is 1.96 N / 15 mm width or more and 7.84 N / 15 mm width or less at 25 ° C., 0.8 N / 15 mm width or more at 95 ° C. If an easy peel strength of 4.90 N / 15 mm width or less is obtained, there is no particular limitation. For example, the outer layer may be biaxially stretched nylon, the intermediate layer may be silica-deposited biaxially stretched polyethylene terephthalate, and the seal layer may be polyethylene or polypropylene.

  The package of the present invention can be produced by adhering the above-mentioned lid material and the bottom material of the present invention by an adhesive means such as heat sealing.

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

Example 1
A film having a layer structure (2) was obtained by co-extrusion in all layers, and Example 1 was obtained.
Ny1 (40 μm) / adhesive resin (10 μm) / LLDPE1 (40 μm) / EP1 (10 μm)
Ny1: "Novamid 6Ny" made by Mitsubishi Engineering Plastics
Adhesive resin: "Admer" manufactured by Mitsui Chemicals
LLDPE1: "Moretech" made by Idemitsu Petrochemical
EP1: Blend of LLDPE2 (60%) and polybutene (40%) LLDPE2: Idemitsu Petrochemical's "Moretec" (density 0.916 g / cm ³ ) Melting point 119 ° C
Polybutene: Mitsui Chemicals' Toughmer

(Example 2)
A film having a layer structure (15) was obtained by coextrusion of all layers, and was used as Example 2.
PP1 (30 μm) / Adhesive resin (10 μm) / EVOH (10 μm) / Ny2 (30 μm) / Adhesive resin (10 μm) / PP1 (20 μm) / EP2 (10 μm)
Ny2: “Novamid 6-66Ny” manufactured by Mitsubishi Engineering Plastics Co., Ltd. 6-66 copolymer with Ny ratio of 15%
EVOH: Kuraray "Eval" (44 mol type)
EP2: Blend of LDPE (50%) and PP1 (50%) LDPE: “Novatec PE” (density 0.924 g / cm ³ ) made by Nippon Polyethylene Melting point 112 ° C.
PP1: "Novatec PP" (Random Copolymer) made by Nippon Polypro

(Example 3)
A film having a layer structure (3) was obtained by co-extrusion in all layers, and Example 3 was obtained.
Ny1 (40 μm) / adhesive resin (10 μm) / EVA1 (40 μm) / EP3 (10 μm)
Ny1: "Novamid 6Ny" made by Mitsubishi Engineering Plastics
Adhesive resin: "Admer" manufactured by Mitsui Chemicals
PP1: "Novatec PP" (Random Copolymer) made by Nippon Polypro
EP3: blend of EVA1 (75%) and polybutene (25%) with a vinyl acetate content of 5% by mass EVA1: "Novatec EVA" made by Nippon Polyethylene Melting point: 108 ° C

Example 4
A film having a layer structure (4) was obtained by co-extrusion in all layers, and Example 4 was obtained.
Ny1 (40 μm) / adhesive resin (10 μm) / PP1 (40 μm) / EP4 (10 μm)
Ny1: "Novamid 6Ny" made by Mitsubishi Engineering Plastics
Adhesive resin: "Admer" manufactured by Mitsui Chemicals
PP1: "Novatec PP" (Random Copolymer) made by Nippon Polypro
EP4: Blend of ionomer (70%) and PP1 (30%)
Ionomer: "High Milan" made by Mitsui DuPont Polychemicals, melting point 97 ° C

(Example 5)
A film having a layer structure (16) was obtained by co-extrusion in all layers, and Example 5 was obtained.
LLDPE1 (30 μm) / Adhesive resin (10 μm) / EVOH (10 μm) / Ny2 (30 μm) / Adhesive resin (10 μm) / LLDPE1 (20 μm) / EP2 (10 μm)
LLDPE1: "Moretech" made by Idemitsu Petrochemical
Adhesive resin: "Admer" manufactured by Mitsui Chemicals
EVOH: Kuraray "Eval" (44 mol type)
Ny2: “Novamid 6-66Ny” manufactured by Mitsubishi Engineering Plastics Co., Ltd. 6-66 copolymer with Ny ratio of 15%
EP2: Blend of LDPE (50%) and PP1 (50%)

(Example 6)
A film having a layer structure (13) was obtained by coextrusion of all layers, and Example 6 was obtained.
PP1 (30 μm) / Adhesive resin (10 μm) / EVOH (10 μm) / Ny2 (30 μm) / Adhesive resin (10 μm) / LLDPE1 (20 μm) / EP2 (10 μm)
PP1: "Novatec PP" (Random Copolymer) made by Nippon Polypro
Adhesive resin: "Admer" manufactured by Mitsui Chemicals
EVOH: Kuraray "Eval" (44 mol type)
Ny2: “Novamid 6-66Ny” manufactured by Mitsubishi Engineering Plastics Co., Ltd. 6-66 copolymer with Ny ratio of 15%
EP2: Blend of LDPE (50%) and PP1 (50%)

(Comparative Example 1)
A film having a layer structure (2) was obtained by coextrusion of all layers, and was designated as Comparative Example 1.
Ny1 (40 μm) / adhesive resin (10 μm) / LLDPE1 (40 μm) / EP3 (10 μm)
EP3: Blend of LLDPE2 (35%) and polybutene (65%)

(Comparative Example 2)
A film having a layer structure (2) was obtained by coextrusion of all layers, and was designated as Comparative Example 2.
Ny (40 μm) / adhesive resin (10 μm) / LLDPE1 (40 μm) / EP4 (10 μm)
EP4: Blend of LLDPE2 (85%) and polybutene (15%)

(Comparative Example 3)
A film having a layer configuration (15) was obtained by coextrusion of all layers, and was designated as Comparative Example 3.
PP1 (30 μm) / Adhesive resin (10 μm) / EVOH (10 μm) / Ny2 (30 μm) / Adhesive resin (10 μm) / PP1 (20 μm) / EP5 (10 μm)
EP5: A blend of EVA2 (60%) and polybutene (40%) with a vinyl acetate content of 20% EVA2: "Novatech EVA" made by Nippon Polyethylene Melting point: 89 ° C

[Preparation of packed sample]
Using a deep drawing packaging machine (FV6300 manufactured by Omori Machine Industry Co., Ltd.), it was deep drawn into a shape having a length of 160 mm, a width of 120 mm, and a drawing depth of 25 mm.

In addition, the following were used for the lid | cover material.
(Cover material of Example 1, Comparative Examples 1-3)
It was produced by the dry lamination method with the following configuration. In the following, “//” is indicated between the layers to indicate a dry laminate.
ONy (15 μm) // LLDPE (70 μm)
ONy: Santo Neil SNR-XT (biaxially stretched product made by Mitsubishi Plastics)
LLDPE: L-6102 (Toyobo Co., Ltd.)

(Cover material of Examples 2-6)
It was produced by the dry lamination method with the following configuration.
Barrier Ny (15 μm) // CPP (70 μm)
Barrier Ny: Super Neal S-PR XT (biaxially stretched product made by Mitsubishi Plastics)
CPP: P1153 (Toyobo Co., Ltd.)

[Evaluation methods]
<Easy peel strength>
The seal part of the pack product was cut into a strip shape having a width of 15 mm with respect to the film flow direction, and the lid material and the bottom material were peeled off at a speed of 200 mm / min using a tensile tester in an atmosphere of 25 ° C. or 95 ° C. The maximum load at that time was defined as easy peel strength.

<Peelability>
When the packaged product was peeled off by hand, the one with good openability was marked with ○, and the one that was heavy and difficult to open was marked with ×.

<Breaking resistance>
10 wrappings are made, stacked in 5 layers, packed in cardboard cases in 2 rows, and dropped when dropped to the concrete surface 5 times from a height of 1.5 m under freezing (−18 ° C.) conditions. The case where there was no bag was marked with ◯, and the case where there was a broken bag was marked with ×.

<Boil resistance>
When the package was boiled at 95 ° C. for 30 minutes, the one without any broken bag was marked with “◯”, and the one with broken bag was marked with “×”.

<Appropriate for microwave oven>
The package was placed in a microwave oven (500 W), and the one that could be opened smoothly with internal pressure was marked with “◯”, and the one that burst and confirmed the scattering of the contents was marked with “x”.

  Examples 1 to 6 had good openability and could be opened smoothly by internal pressure without tearing even in a drop test and boiling, and without bursting in a microwave oven.

  On the other hand, in Comparative Example 1, since the easy peel strength at 25 ° C. was weak, some bags were broken from the heat seal portion by the drop test. Since Comparative Example 2 has a strong easy peel strength at 25 ° C., it has poor peelability and is difficult to open. In addition, since the easy peel strength at 95 ° C. is strong, the internal pressure may rise too much when applied to a microwave oven, and the contents may rupture and scatter. In Comparative Example 3, since the easy peel strength at 95 ° C. was weak, there was a case where the bag was broken from the heat seal part during boiling.

It is explanatory drawing which shows the package body before joining. It is explanatory drawing which shows the package body after joining of a cover material and a bottom material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cover material 20 Bottom material 30 Concave part 40 Contents, such as pasta 50 Heat seal part

Claims (9)

  A polyamide resin (PA) layer and an easy peel strength of 1.96 N / 15 mm width to 7.84 N / 15 mm width at 25 ° C. and 0.8 N / 15 mm width to 4.90 N / 15 mm width at 95 ° C. And a deep drawing film having at least an easy peel layer having cohesive failure. 2. The easy peel layer is composed of a mixture of the following resin A and resin B, and the contents of resins A and B are 40% by mass to 80% by mass and 20% by mass to 60% by mass, respectively. The film for deep drawing described in 1.
Resin A: Linear low density polyethylene (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer having a melting point of 90 ° C. or higher Polymer (EEA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-methyl acrylate copolymer (EMA) and at least selected from the group consisting of these ionomers Type 1 Resin B: Polypropylene (PP) or Polybutene (PB)   The film for deep drawing according to claim 1 or 2, wherein at least one polypropylene resin (PP) layer is provided outside and / or inside the PA layer.   The deep drawing film according to any one of claims 1 to 3, further comprising at least one ethylene-vinyl acetate copolymer (EVA) layer or polyethylene resin (PE) layer outside and / or inside the PA layer. .   The film for deep drawing according to any one of claims 1 to 4, further comprising at least one ethylene-vinyl acetate copolymer saponified product (EVOH) layer outside and / or inside the PA layer.   The deep drawing film according to any one of claims 3 to 5, further comprising at least one adhesive resin layer between the PA layer and a layer formed outside and / or inside the PA layer.   A bottom material for a deep-drawn package, which is formed from the deep-drawing film according to any one of claims 1 to 6.   A deep drawn package using the bottom material according to claim 7. The deep-drawn package according to claim 8, wherein the use is for microwave heating.

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