JPH06344492A - Packing material and package for moist food - Google Patents

Abstract

PURPOSE:To provide a packing material and package for moist food composed of a gas barrier film gentle to the global environment and excellent in food shelf stability. CONSTITUTION:A packing material and package for moist food enhanced in gas barrier properties and bending properties, being gentle to the global environment and excellent in practical characteristics can be provided by using a gas barrier film obtained by forming an aluminum oxide membrane on a plastic base material and characterized by that the specific gravity of the membrane is 1.80-2.20 as the whole of constitution or a part thereof.

Description

Detailed Description of the Invention

[0001]

The present invention has excellent gas barrier properties,
Various kinds of pickles such as board, string konjac, takuan pickles, soy sauce pickles, Nara pickles, miso and sauce, soy sauce, sauce, ketchup, mayonnaise, etc. TECHNICAL FIELD The present invention relates to a packaging material and package for aquatic foods suitable for storing seasonings and the like.

[0002]

2. Description of the Related Art Laminated various plastic films have been used as packaging materials and packages for water foods having excellent gas barrier properties. For example, a laminate of a nylon film and a PE (polyethylene) film or a nylon film and a CPP (unstretched polypropylene) film. In addition, a bag, a cup, a bag, a cup, or the like, which is obtained by vapor-depositing aluminum on a nylon film, or by using a product in which vinylidene chloride or ethylene vinyl alcohol copolymer is replaced, is laminated with PE or CPP film. Various packages such as trays are made and used. Recently, a gas barrier film using a thin film such as silicon oxide is also used.

[0003]

The conventional packaging materials and packages for aquatic foods have the following problems. The aluminum foil or the one using aluminum vapor deposition has an excellent gas barrier property, but it is opaque and has a drawback that the contents at the time of packaging cannot be seen.
Further, when aluminum is included in a part of the packaging material for aquatic foods and the structure of the package, there is a problem that the plastic film cannot be collected and reused (recycled). Those containing vinylidene chloride or ethylene vinyl alcohol copolymer as part of the packaging material for aquatic foods and the configuration of the packaging have insufficient gas barrier properties such as water vapor and oxygen,
Storage period of contents is short. In addition, vinylidene chloride-based compounds are easily pyrolyzed, making recycling difficult,
There are also concerns about the impact on the global environment, such as the generation of chlorine gas when incinerated. Further, although the ethylene vinyl alcohol type has an excellent barrier property during drying, the oxygen barrier property remarkably deteriorates under high humidity, and the storage period becomes short.

JP-B-51-48511 proposes a gas barrier film in which Si _x O _y (for example, SiO ₂ ) is vapor-deposited on the surface of a synthetic resin, but a SiO _x system (x = 1.3 to 1.8) has a brown color, and its coating is fragile, and when a packaging material for water foods and a packaging body having this as a part or the whole of the composition are handled harshly, a gas barrier. There is a drawback that the property is greatly reduced.

[0005]

DISCLOSURE OF THE INVENTION The present invention is a package for aquatic foods, which has a gas barrier film which is excellent in gas barrier property, has high flex resistance, and is economically advantageous, as a part or all of the constitution. The purpose is to provide materials and packages. That is, the present invention provides a gas barrier film characterized in that a thin film having a composition mainly composed of silicon oxide is provided on at least one surface of a plastic substrate, and the specific gravity of the thin film is 1.80 to 2.20. Is a packaging material and package for aquatic foods which are all or a part of the above.

The plastic substrate referred to in the present invention is a film obtained by melt-extruding an organic polymer and, if necessary, stretching, cooling and heat setting in the longitudinal direction and / or the width direction, As the organic polymer, polyethylene, polypropylene, polyethylene terephthalate, polyethylene-2,6-naphthalate, nylon 6, nylon 4,
Examples thereof include nylon 66, nylon 12, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, wholly aromatic polyamide, polyamideimide, polyimide, polyetherimide, polysulfone, polyphenylene sulfide, and polyphenylene oxide. Further, these (organic polymer) organic polymers may be copolymerized or blended with a small amount of another organic polymer.

Further, known additives such as an ultraviolet absorber, an antistatic agent, a plasticizer, a lubricant and a coloring agent may be added to the organic polymer, and its transparency is not particularly limited. However, when it is used as a transparent gas barrier film, a film having a transmittance of 50% or more is preferable. The plastic film of the present invention may be subjected to corona discharge treatment, glow discharge treatment, or other surface roughening treatment prior to laminating the thin film layers, as long as the object of the present invention is not impaired. Also, it may be subjected to anchor coat treatment, printing, or decoration. The plastic film of the present invention preferably has a thickness of 5 to 500 μm, more preferably 8 to 300 μm.

The silicon oxide thin film in the present invention means Si, S
It is considered to be composed of iO, SiO _2, etc., and the ratio of these differs depending on the production conditions. A trace amount (up to 3% of all components) in this component within the range where the characteristics are not impaired.
Other components may be included. Although the thickness of the thin film is not particularly limited, it is preferably 50 to 8000 Å, more preferably 70 to 5,000 Å, from the viewpoint of gas barrier property and flexibility. For the production of such a silicon oxide thin film, a vacuum vapor deposition method, a sputtering method, an ion plating method
PVD method (physical vapor deposition) such as towing, or C
The VD method (chemical vapor deposition method) or the like is appropriately used. For example,
In the vacuum vapor deposition method, SiO or Si is used as a vapor deposition source material.
A mixture of SiO ₂ is used also as a heating method, resistance heating, high frequency induction heating, electron beam - can be used beam heating or the like. In addition, as a reactive gas, oxygen,
Nitrogen, water vapor, or the like may be introduced, or reactive vapor deposition using means such as ozone addition or ion assist may be used. Further, the production conditions may be changed as long as the object of the present invention is not impaired by applying a bias or the like to the substrate, raising the substrate temperature, or cooling. Sputtering method and C
The same applies to other preparation methods such as the VD method.

In order to form such a silicon oxide thin film, PV such as vacuum deposition method, sputtering method and ion plating is used.
The D method (physical vapor deposition method), the CVD method (chemical vapor deposition method), or the like is appropriately used. For example, in the vacuum evaporation method, Si, SiO, SiO ₂ or the like is used as the evaporation source material, and as the heating method, resistance heating, high frequency induction heating, electron beam heating or the like can be used. Further, as the reactive gas, oxygen, nitrogen, water vapor or the like may be introduced, or reactive vapor deposition using means such as ozone addition or ion assist may be used. Further, the production conditions may be changed as long as the object of the present invention is not impaired by applying a bias or the like to the substrate, raising the substrate temperature, or cooling. The same applies to other preparation methods such as the sputtering method and the CVD method. Further, the product of the present invention may be used as it is, but may be used by laminating or coating another organic polymer film or thin layer.

The specific gravity referred to in the present invention is the ratio of the mass of a substance that occupies a certain volume at a certain temperature to the mass of a standard substance having the same volume (water at 4 ° C.). The measurement of specific gravity is
Usually, the mass and volume of an object may be measured and the ratio to the mass of water of the same volume at 4 ° C. may be obtained, but it is difficult to measure the volume in the measurement of the thin film of the present invention. Therefore, first, the thin film is peeled from the substrate, or only the substrate is melted to form a single film made of only the thin film, and then (JIS K
7112), it is desirable to use a specific gravity measurement method. For example, in the float-sink method, the sample can be dipped in a solution of known specific gravity, and the specific gravity of the thin film can be measured from the floating state. As this solution, a mixed solution of carbon tetrachloride and bromoform, or methylene iodide can be used. The specific gravity value can also be measured by a density gradient tube method in which a single membrane is immersed in a solution having a continuous density gradient.

When the specific gravity of the thin film thus obtained is smaller than 1.80, the structure of the silicon oxide thin film becomes coarse and sufficient gas barrier properties cannot be obtained. Also,
When the specific gravity of the thin film is larger than 2.20, the initial gas barrier property after film formation is excellent, but the film becomes too hard and mechanical properties, particularly gelbo property are inferior. Due to handling and the like, the gas barrier property is likely to deteriorate, and it is not suitable for use as a packaging material. For the above reasons, the preferred specific gravity of the silicon oxide thin film as a packaging material and package for aquatic foods is 1.8.
0 to 2.20, and more preferably 1.90 to 2.1.
5 and more preferably 1.95 to 2.15.

The packaging material for aquatic foods according to the present invention is laminated with various films according to the required characteristics of the contents to be packaged.
The typical laminating structure is gas barrier film (on NY) / PE, gas barrier film (N
Y top) / CPP, gas barrier film (on PET) /
PE, gas barrier film (on PET) / CPP, etc. are considered. Further, it may be printed for decoration or for explaining the contents, or may be laminated with a design film or a reinforcing agent. The package in the present invention includes a bag,
There are lid materials, cups, tubes, standing packs, trays, etc., and there is no particular limitation on the shape and type. For example, the bag type packaging type is a pillow type or a three-way sheet.
, Square seal, etc. are used. A gas barrier film is used as all or part of the configuration of these packaging materials and packages. As the contents to which the water food package of the present invention can be applied, a plate, thread konjac, pickled pickles,
Various kinds of pickles such as soy sauce pickles, Nara pickles, miso dishes and sauces, foods enclosed with soup stock, noodle soup, etc., seasonings such as soy sauce, sauces, etc. Not a thing.

The present invention will be described below with reference to examples. Example 1 (Example 1) As a vapor deposition source, particulate Si (purity 99.99%) and SiO ₂ (purity 9: about 3 to 5 mm) were used.
9.9%) was used to form a silicon oxide-based gas barrier thin film on a nylon film having a thickness of 15 μm (Toyobo Co., Ltd .: N1100) by an electron beam vapor deposition method. The vapor deposition material was divided into two without mixing. An electron gun (hereinafter referred to as EB gun) was used as a heating source, and each of Si and SiO ₂ was heated in a time division manner. The emission current of the EB gun at that time was set to 0.7 to 1.8 A, and the heating ratio to Si and SiO ₂ was changed to 10:10 to 60:10. The film feed speed is changed from 30 to 120 m / min, 40
A film with a thickness of 0 to 4000 Å (angstrom) was formed.
Also, the vapor pressure is changed from 1 × 10 ^-5 〜 by changing the supply amount of oxygen gas.
The conditions were changed up to 8 × 10 ⁻³ Torr. In order to measure the specific gravity of the thin film, a part of the obtained gas barrier film was cut out, the nylon film was dissolved, and then the specific gravity was measured by the float-sink method. Furthermore, by laminating a gas barrier film and PE (polyethylene) 40 μm, Example 1-
Was prepared and the oxygen barrier property of this packaging film was measured. The oxygen barrier property was also measured after the bending fatigue resistance test.

Next, a method for measuring oxygen permeability and a method for testing flex fatigue resistance will be described. -Measuring method of oxygen transmission rate The oxygen transmission rate of the created gas barrier film was measured by an oxygen transmission rate measurement apparatus (OX-TRAN manufactured by Modern Controls Co., Ltd.).
100). -Test method of flex fatigue resistance (hereinafter gelbo property) Flex fatigue resistance was evaluated using a so-called gelbo flex tester (manufactured by Rigaku Kogyo Co., Ltd.). The condition is (MIL-B131H) 11.2 inches x 8 inches
The sample piece of ch is made into a cylindrical shape with a diameter of 3 (1/2) inch, both ends are held, the initial gripping interval is 7 inch, and a twist of 400 degrees is added at a stroke of 3 (1/2) inch. Repeated reciprocating motion of 40 times / m
It was carried out at a speed of in at 20 ° C. and a relative humidity of 65%. As a result, the examples showed excellent oxygen barrier properties (Table 1).

Comparative Example 1 The vapor pressure was changed from 1 × 10 × ^-3 to 2 by changing the supply amount of oxygen gas.
Comparative Example 1 was prepared in the same manner as in Example except that the content was changed to × 10 ^-2 Torr. Also for this comparative example,
After the nylon film was dissolved, the specific gravity was measured by the float-sink method. Gas barrier film and PE (polyethylene)
40 μm was laminated to produce Comparative Examples 1 to 1 and the oxygen barrier property of this packaging film was measured. As a result, it was found that it was slightly inferior to the examples.
(Table 1)

Comparative Example 2 As a comparative example, 1-nylon (15 μm) / PE (4
0 μm), vinylidene chloride nylon (K-N
Y) / PE (40 μm), Al foil (7 μm) / PE
(40 μm) was prepared. The oxygen barrier properties of these packaging films were measured. Next, the film of Example 1 was put into a pillow-shaped bag-making and filling machine to fill a small pouch with plate konjac. This sample was left in a room at 40 ° C. and 90% RH for 1 month and then opened and tasted. The taste of konjac,
There was no change in flavor. Each film of Comparative Example also, using a bag-making filling machine in the same manner as in Example, filled with plate konjac,
Under the same conditions, the sample was left open and tasted, but it was judged that konjac had a poor taste. Next, the film of the example was put into a bag-making filling machine and heat-sterilized (75 ° C. × 10 min) to fill the pickles (Takuan-zuke) while forming into small bags. This sample was left in a room at 40 ° C. and 90% RH for 3 months and then opened and tasted, but there was no change in the taste and flavor of Takuan pickles. Each film of Comparative Example was also filled with Takuanzuke using a bag-making filling machine in the same manner as in Example, opened after being left to stand under the same conditions, and tasted, but there was an oxidative odor except for Al foil products,
The taste was judged to be poor. When these films were incinerated, almost all but the Al foil product could be incinerated, but Al metal dust remained on the Al foil product.

[0017]

INDUSTRIAL APPLICABILITY In a packaging material and package for aquatic foods, which uses a gas barrier film in which a silicon oxide thin film is formed on a plastic substrate, the specific gravity of the thin film is 1.80.
By using the gas barrier film characterized by being ~ 2.20 as the whole or a part of the constitution, it is highly suitable for packaging having high gas barrier properties, high flexibility, and environmentally friendly practical properties. It turns out that it is a useful packaging material and package for aquatic foods.

[0018]

[Table 1]

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Toru Otani 1-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd. Research Institute (72) Inventor Toshiyuki Otani 1-1-1, Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd. General Research Institute (72) Inventor Yozo Yamada 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd. General Research Institute

Claims (2)

[Claims] 1. A plastic substrate on at least one side,
A packaging material for aquatic foods, which comprises a thin film having a composition mainly composed of silicon oxide and has a specific gravity of 1.80 to 2.20 as a whole or a part of the constitution of a gas barrier film. 2. A plastic substrate on at least one side,
A package for aquatic foods, which comprises a gas barrier film comprising a thin film mainly composed of silicon oxide and having a specific gravity of 1.80 to 2.20 as a whole or a part thereof.