JPH1135075A - Deep drawn packaging body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the gloss and the transparency from being spoiled even when a boil-sterilization is performed with hot water by a method wherein as a sealable resin layer for the innermost layer of a bottom member film for deep draw-forming and a lid member film, a copolymerized composite film for which an ethylene-acrylic acid random copolymer resin layer is arranged, is used. SOLUTION: By arranging a nylon resin layer on the outermost layer by a bottom member film, the whitening of the film at the time of boil sterilization and the blocking between a packaging body with each other are prevented from arising, and glass and transparency are imparted to the film. The biaxially drawn nylon or a biaxially drawn polypropylene which is used for the outermost layer of the lid member film, prevents the gloss from decreasing due to a roughness of the contact surface when a hot plate comes into contact with the outermost layer surface at the time of heat- sealing with the bottom member film. This packaging body which is vacuum-packaged using the bottom member film and the lid member film is excellent in gloss, transparency and pin-hole resistance, and even when a boil sterilization by hot water at 95 deg.C or higher is performed, blocking and the whitening of the film are not generated, and the packaging body is excellent in both a physical property and an appearance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deep drawn package for vacuum packaging, and more particularly to a composite film which is excellent in gloss and transparency and can be subjected to a boil sterilization treatment.

[0002]

2. Description of the Related Art A so-called boil-sterilizing package in which a bottom material film formed by deep drawing is filled with an object to be packaged, such as ham, and the lid material film is heat-sealed in a vacuum state and then subjected to a boil sterilization treatment with hot water. The bottom film used for the material is composed of an outermost layer, an intermediate layer and an innermost layer.The outermost layer is a polyamide resin layer, the intermediate layer is a resin layer having a gas barrier resin layer, and the innermost layer is an ionomer as a sealing resin layer. A composite film having a configuration in which a resin or an ethylene-vinyl acetate copolymer resin layer is disposed is used. As a lid material film that is heat-sealed to the bottom material, the innermost sealing resin layer is made the same as that of the bottom material film. A composite film of the configuration is used. However, the sealing resin layer used in these combinations has a problem that whitening occurs due to crystallization of the resin during heat sealing or boiling sterilization treatment with hot water, and the appearance of the product is impaired due to a decrease in transparency. Was.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel deep-drawn package which solves the above-mentioned problems.

[0004]

The above object is achieved by the following means.

That is, in the present invention, the outermost layer is sandwiched between a 12 nylon resin layer or a copolymer polyamide resin layer of 12 nylon and 6 nylon, and the intermediate layer is sandwiched between polyolefin-based adhesive resin layers as a bottom material film for deep drawing. Polyamide resin layer or polyamide resin layer sandwiched between polyolefin adhesive resin layer and ethylene-vinyl acetate copolymer saponified resin layer, co-extruded composite film in which ethylene-acrylic acid random copolymer resin is disposed in the innermost layer Used as the lid material film, the outermost layer is nylon 6, the intermediate layer is a polyamide resin layer or a polyamide resin layer and a saponified ethylene-vinyl acetate copolymer resin layer, and the innermost layer is an ethylene-acrylic acid random copolymer resin. It is intended to propose a deep drawn package characterized by using a co-extruded composite film provided with layers, To use the above base material film includes a biaxially oriented nylon or biaxially oriented polypropylene in the outer layer of the lid material film using a composite film obtained by dry lamination.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

In the bottom material film of the present invention, the 12 nylon resin layer or the copolymer layer of 12 nylon and 6 nylon (hereinafter referred to as "nylon 12/6") resin layer is disposed on the outermost layer because of boiling sterilization. It is effective for preventing whitening of the film and blocking of the packages during processing, and is also effective for imparting gloss and transparency to the film.

The thickness of the 12 nylon resin layer or the nylon 12/6 resin layer is preferably 15% or less of the entire composite film. If it exceeds 15%, the pinhole resistance is poor and the film curls. Tends to be easy. The specific thickness is preferably in the range of 5 to 30 μm.

The intermediate layer of the present invention is mainly a gas barrier resin layer, and is a polyamide resin layer or a polyamide resin layer and an ethylene-vinyl acetate saponified resin layer (hereinafter referred to as “EV”).
OH ". ). As the polyamide resin layer, nylon 6, nylon 66, nylon 6 /
66, a resin such as nylon 6I / 6T can be suitably used,
Further, the same nylon 12/6 resin as the outermost layer may be used. E
As the VOH resin, those having an ethylene content of 30 to 60 mol% and a degree of saponification of 95% or more are preferable from the viewpoint of moldability and barrier properties.

[0010] The thickness of the intermediate layer of the bottom material film of the present invention may be in the range of 10 to 70 µm when only the polyamide resin layer is used. 10-70 μm, EV
The OH resin layer may have a thickness in the range of 5 to 30 μm. Also.
The thickness of the intermediate layer of the lid material film may be in the range of 5 to 30 μm in the case of only the polyamide resin layer, and the polyamide resin layer and the EVOH resin layer may have a polyamide resin layer of 5 to 30 μm and an EVOH resin. 5-30 μm layer
Should be within the range.

The ethylene-acrylic acid random copolymer (hereinafter referred to as "EAA" resin) resin used in the innermost layer of the present invention preferably has an acrylic acid content of 3 to 12% by weight. Is different from an ionomer obtained by reacting a reactive metal compound. It is necessary to provide a polyolefin-based adhesive resin layer between the outermost layer and the intermediate layer of the bottom material film of the present invention, and between the intermediate layer and the sealing resin layer, and as a resin to be used, an unsaturated carboxylic acid or A modified polyolefin resin grafted with at least one monomer selected from its derivatives can be suitably used. Further, the pinhole resistance of the entire film can be improved by disposing a polyolefin-based adhesive resin layer having excellent pinhole resistance on both sides of the gas barrier resin layer in which pinholes are easily generated. The thickness of each polyolefin-based adhesive resin layer may be in the range of 5 to 20 μm. Between the outermost layer and the intermediate layer of the lidding film of the first invention,
It is preferable to provide a polyolefin-based adhesive resin layer between the intermediate layer and the sealing resin layer for the same reason as described above.

The adhesion between the outermost layer and the intermediate layer of the lid film of the second invention is preferably performed by dry lamination. Further, biaxially stretched nylon (hereinafter referred to as “ON
y ". ) Or biaxially oriented polypropylene (hereinafter,
It is called "OPP." ) Is suitable for preventing the hot plate from contacting the outermost layer surface of the lid material film when heat sealing with the bottom material film to prevent the contact surface from being roughened and reducing the gloss. The thickness is preferably 15 to 50 μm.

The package which is vacuum-packaged by using the above-mentioned bottom material film and lid material film is excellent in gloss, transparency and pinhole resistance. A package having excellent physical properties and appearance without whitening is obtained.

[0014]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples.

Example 1 Nylon 12 having a thickness of 10 μm and a modified ethylene-α-olefin copolymer having a thickness of 15 μm (hereinafter referred to as AD1)
And nylon 6/66 with a thickness of 60 μm and E with a thickness of 10 μm
VOH, 10 μm thick carboxylic acid-modified ethylene-vinyl acetate copolymer (hereinafter referred to as AD2), and 95 μm thick
m co-extruded with EAA to obtain a 6-layer coextruded composite film, which was used as a bottom film.

Further, nylon 6 having a thickness of 7 μm and nylon 6 having a thickness of 7 μm
AD1 and 25μm thick nylon 6/66 and 7μm thick
m EVOH, 7 μm thick AD2 and 34 μm thick E
EA was co-extruded to form a 6-layer co-extruded composite film, which was used as a cover film.

Example 2 A composite film having the following six layers was co-extruded.
The obtained co-extruded composite film was used as a bottom material film.

Nylon 12 (thickness 10 μm) / AD1
(Thickness 15 μm) / Nylon 6/66 (Thickness 60 μm)
/ EVOH (thickness 10 μm) / AD2 (thickness 10 μm)
m) / EAA (thickness: 95 μm) Further, a composite film having a layer configuration of the following six layers was coextruded.

Nylon 6 (5 μm thickness) / AD1 (5 μm thickness) / Nylon 6/66 (20 μm thickness) / EVO
H (5 μm thickness) / AD2 (5 μm thickness) / EAA (35 μm thickness) 20 μm thickness on the nylon 6 side of the co-extruded composite film
A composite film obtained by dry laminating OPP was used as a cover film.

Example 3 The bottom material film had the same structure as in Example 1.

A composite film having the following six layers is co-extruded, and nylon 6 (thickness 5 μm) / AD1 (thickness 5 μm) / nylon 6/66 (thickness 20 μm) / EVOH (thickness 5 μm)
m) / AD2 (5 μm thickness) / EAA (35 μm thickness) 15 μm thickness on the nylon 6 side of the coextruded composite film
The composite film obtained by dry-laminating ONy was used as a film for a lid material.

Comparative Example 1 A composite film composed of the following six layers was co-extruded.
The obtained co-extruded composite film was used as a bottom material film.

Nylon 6 (thickness 10 μm) / AD1 (thickness 15 μm) / Nylon 6/66 (thickness 60 μm) / E
VOH (thickness 10 μm) / AD2 (thickness 10 μm) / E
VA (thickness: 95 μm) A composite film having a layer configuration consisting of the following six layers was co-extruded, and the obtained co-extruded composite film was used as a cover film.

Nylon 6 (7 μm thickness) / AD1 (7 μm thickness) / Nylon (6/66) (25 μm thickness) / E
VOH (7 μm thickness) / AD2 (7 μm thickness) / EVA
(Thickness: 34 μm) Comparative Example 2 A composite film composed of the following six layers was co-extruded.
The obtained co-extruded composite film was used as a bottom material film.

Nylon 6 (10 μm thickness) / AD1 (15 μm thickness) / Nylon (6/66) (60 μm thickness)
/ EVOH (thickness 10μm) / AD2 (thickness 10μm)
/ Ionomer resin (thickness: 95 μm) A composite film having the following six layers was co-extruded, and the obtained co-extruded composite film was used as a cover film.

Nylon 6 / AD1 / nylon (6/6
6) (25 μm thickness) / EVOH (7 μm thickness) / AD
2 (thickness 7 μm) / ionomer resin (thickness 34 μm) Comparative Example 3 A composite film composed of the following six layers was co-extruded.
The obtained co-extruded composite film was used as a bottom material film.

Nylon 6 (10 μm thickness) / AD1 (15 μm thickness) / Nylon (6/66) (60 μm thickness)
/ EVOH (thickness 10μm) / AD2 (thickness 10μm)
/ EVA (thickness 95 μm) Co-extruded a composite film consisting of the following six layers, nylon 6 (thickness 5 μm) / AD1 (thickness 5 μm) / nylon (6/66) (thickness 20 μm) / EVOH (thickness 5 μm) / AD2 (thickness 7 μm) / EVA (thickness 35 μm)
m) 20 μm thickness on the nylon 6 side of the co-extruded composite film
Was laminated by dry lamination to form a cover film.

Comparative Example 4 A composite film consisting of the following six layers was co-extruded.
The obtained co-extruded composite film was used as a bottom material film.

Nylon 6 (10 μm thickness) / AD1 (15 μm thickness) / Nylon (6/66) (60 μm thickness)
/ EVOH (thickness 10μm) / AD2 (thickness 10μm)
/ Ionomer resin (95 μm thickness) Co-extruded a composite film consisting of the following 6 layers: Nylon 6 (5 μm thickness) / AD1 (5 μm thickness) / Nylon (6/66) (20 μm thickness) / EVOH (5 μm thickness) ) / AD2 (thickness 5 m) / ionomer A (thickness 35 μm) A thickness of 2 was applied to the nylon 6 side of the obtained co-extruded composite film.
OPP of 0 μm was dry-laminated to form a cover film.

Using the composite films described in the above Examples and Comparative Examples, a deep drawing packaging machine (F) manufactured by Omori Machinery Co., Ltd.
V-6300), 500 g of amorphous ham was vacuum-packaged and sterilized in hot water at 98 ° C. for 30 minutes in boil for 30 minutes. The gloss after treatment (with or without blocking), the transparency before and after the boil sterilization treatment (the film (Whitening state) was evaluated.

As a result, the gloss of each of the examples was better than that of the comparative example. Regarding the transparency, the one of the comparative example was slightly whitened and the transparency was lowered, while the one of the examples was good without any change in the transparency.

[0032]

The deep drawn package of the present invention can be suitably used as a vacuum packaging material, since gloss and transparency are not impaired even when subjected to boiling treatment with hot water.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B65D 1/09 B65D 1/00 B

Claims (2)

[Claims] 1. A polyamide resin layer in which the outermost layer is a 12-nylon resin layer or a copolymer polyamide resin layer of 12-nylon and 6-nylon, and an intermediate layer is a polyolefin-based adhesive resin layer as a bottom material film for deep drawing. Or, using a co-extruded composite film in which a polyamide resin layer and an ethylene-vinyl acetate copolymer saponified resin layer sandwiched between polyolefin-based adhesive resin layers, and an ethylene-acrylic acid random copolymer resin in the innermost layer, As a lid material film,
A co-extruded composite film in which the outermost layer is nylon 6, the intermediate layer is a polyamide resin layer, or a polyamide resin layer and a saponified ethylene-vinyl acetate copolymer resin layer, and the innermost layer is an ethylene-acrylic acid random copolymer resin layer. A deep drawn package characterized by using: 2. The deep drawn package according to claim 1, wherein a composite film obtained by dry laminating biaxially oriented nylon or biaxially oriented polypropylene is used as an outer layer of the lid material film.