JPS5946865B2 - packaging goods - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a packaged article, and an object of the present invention is to prevent the packaged article from being altered or deteriorated due to harmful gases mixed in the packaging container.

In the packaging of foodstuffs and precision electrical and mechanical parts, hermetic packaging materials that can be isolated from the outside air are used to prevent deterioration, corrosion, staining, etc. due to contact with the outside air.

However, it is often difficult to achieve complete sealing from the outside air, and it is impossible to avoid oxidation, corrosion, and deterioration of the packaged articles due to gases existing in the gaps between the articles in the packaging container.

The most important cause of such problems is that reactive gases such as oxygen are mixed in and remain inside the packaging container. As a result, in food packaging, food materials undergo corrosion due to oxidation, deterioration, and microbial growth occurs in food containers containing oxygen, and in packaging for electrical contact materials and mechanical parts, rust occurs due to oxidation of the materials. do. Gas replacement packaging and vacuum packaging have been conventionally used as methods for preventing oxygen remaining in packaging containers from causing deterioration of packaged articles.

However, in gas replacement packaging where the air in the packaging container is replaced with a gas that does not contain oxygen, such as nitrogen, carbon dioxide, or a mixture thereof, at least 2% by volume is added to the periphery of the nozzle of the replacement device during the sealing process. It is unavoidable that outside air, which normally contains about 4% by volume of oxygen, re-enters the packaging container, and for this reason, it is not possible to prevent the progress of oxidation, deterioration, and corrosion of the product during long-term storage. It is. On the other hand, vacuum packaging, in which the packaging container is evacuated after the packaged product is stored in the packaging container, may not be usable because the packaged product itself contains substances that are easily extracted by vacuum, such as moisture, as in food packaging. Water and water-soluble substances are extracted from the inside of the product and segregated on the surface of the food, which has the disadvantage of impairing taste and flavor.

Furthermore, not only is the vacuum packaging process itself large-scale and expensive, but there are also problems in that there are very few packaging materials that can be kept under vacuum for a long period of time. In addition, there are oxygen scavengers that remove oxygen through a chemical reaction using hydrosulfide, but these have the disadvantage of generating toxic gases such as sulfur dioxide and hydrogen sulfide during the chemical reaction process, and are expensive.

There are also oxygen scavengers that use enzymes such as glucose oxidase, but enzymatic reactions are extremely difficult to control temperature, hydrogen ion concentration, and temperature, making actual use complicated and expensive. The present inventors have solved all of these problems by developing a simple and simple method that can quickly remove harmful gases remaining inside packaging containers and quickly remove harmful gases that enter from the outside during long-term storage. We will consider inexpensive and reliable packaging methods, first focusing on converting harmful gases inside the packaging container into other harmless substances, and then focusing on the catalyst materials needed to cause two or more gases to react with each other. It has been found that by attaching the compound to the inner wall of a packaging container by vacuum deposition, it is highly active and exhibits a catalytic effect even in a very small amount, resulting in an extremely excellent packaging container.

That is, the present invention provides a package in which a thin layer of a catalytic material formed on a base soil by a vacuum deposition method and at least two or more gases that react with each other using the catalytic material as a catalyst coexist inside the package. provide goods;

The detailed contents of the present invention will be explained below.

As a packaging material for goods, it must have good gas barrier properties, good transparency and beauty, and be easy to print in various ways.
Organic polymer films are often used because they are easy to seal and have excellent flexibility. The catalyst-coated substrate used in the present invention includes:
The feature is that all of these commonly used packaging materials can be used. In other words, catalyst-adhesive supports for conventionally known chemical reactions include porous ceramics such as alumina, silica, zirconia, titania, ittria, and ceria, granular materials such as carbon particles and ferrite particles, and silica cloth. , glass cloth, quartz cloth, metal mesh, etc., and all of them cannot be used to form packaging containers for articles or coexist in food packaging containers as in the present invention. Examples of catalyst-adhered substrates used in the invention include polyethylene, polypropylene, polybutene-1, ethylene propylene copolymer, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polystyrene, polyether, and polyvinyl. Raw materials consisting of individual or mixtures of organic polymers such as alcohol, polyester represented by polyethylene terephthalate, ionomer polycarbonate represented by "Surlyn" (manufactured by Dupont), polyamide, polyimide, polyamideimide, cellulose, acetate, etc. Stretched or unstretched films or molded products made of the above-mentioned polymers and organic polymers such as silicone, polyurethane, polysulfone, phenol, melamine, urea resin, and epoxy resin are preferred.

Various known additives, such as heat stabilizers, antioxidants, lubricants, antistatic agents, colorants, clarifying agents, ultraviolet inhibitors, or pigments, are added to these organic polymer base materials. Good too. Furthermore, films made by laminating the above film materials into two or more layers by extrusion lamination, dry lamination, etc., films made by adhering and laminating these films with metal foils such as aluminum foil, or films made by vacuum evaporation, etc. Those coated with metals such as aluminum, zinc, and tin, and those coated with printing can also be used in exactly the same way. In addition, thin metal plates such as tinplate, chrome-plated steel plates, aluminum plates, and anti-rust iron plates, which can be used to form metal packaging containers, as well as glass and paper, can also be used, but they are less likely to adhere to catalysts than organic polymer films. Also, it is unavoidable that the amount of the coating is relatively large.

The shape of these catalyst-coated substrates is not particularly limited due to the nature of the present invention, but the shape may ultimately be a bag-like shape constituting a packaging container,
It needs to be in the shape of a can, a lid, etc., or it needs to be in a shape that can be substantially stored inside the packaging container, such as a label, lining sheet, inner lid, etc.

In the present invention, the catalyst-adhered substrate exhibits the most uniform and efficient catalytic activity when it has good planarity, and furthermore, a substrate with a low saturated water absorption rate can maintain the catalytic activity life for a long period of time. has advantages. In addition, when the catalyst-coated substrate ultimately constitutes the outer wall of the packaging container, in order to remove harmful gases such as oxygen gas over a long period of time, the oxygen permeability of the substrate itself is 10 CC/24 hr-m.
It is most preferable to have a particle diameter of 100 μm or less.

The most effective catalyst materials to be deposited on such substrates are those from the group consisting of palladium, platinum, and rhodium.
Next comes the group consisting of iridium, osmium, and ruthenium.

These consist of a system containing one or more types〇Generally,
A known method for depositing a catalyst material on a substrate is to immerse the substrate in a solution of a metal compound that will serve as a catalyst, allow the surface to be adsorbed, and then reduce it by firing in a high-temperature furnace using a stream of hydrogen. It has been found that it is difficult to develop the catalytic activity in the present invention when the surface is flat or has no water absorbency.

In addition, particle size 1 with palladium coated on the alumina particle surface
Attempts have also been made to coat and dry particles of μ to 500μ using vinyl chloride monovinyl acetate copolymer as a binder, etc., but the activity is low even when filled with a large amount of catalyst material, and the short time is short. It became clear that the catalytic activity was lost over time. The most preferred method for achieving the object of the present invention is to convert the catalyst material such as palladium, platinum, rhodium, etc. into an atomic or molecular gas in a vacuum and then deposit it on a substrate.

Examples of such a vacuum deposition method include a vacuum evaporation method, an ion plating method, and a sputtering method.

In either case, the process involves the step of converting the material into atomic or molecular gases and then redepositing the material onto the substrate. Through this process, the catalyst substances deposited on the substrate reduce their kinetic energy by colliding and cooling on the substrate, and coalesce with each other to form fine island-like structures or network structures with diameters of several 10X to several 100X. It can be applied to the substrate. Among them, when the sputtering method is adopted as a vacuum deposition method, it is possible to create an island-like structure with uniform particle size and small diameter by sufficiently adjusting the sputtering conditions, and when depositing such a structure, the catalytic activity It was found that the highest value can be obtained.

The amount of the catalyst material deposited on the substrate is preferably in the range of 10-7 MOlA to 5 x 10-3 m01/m''; if it is less than 10-7 MOl/m, it is difficult to obtain catalyst activity; /Tri' or more, the catalyst activity relative to the amount of adhesion decreases significantly.

Among them, the adhesion amount is from 10-6m01/i to 5×10-4
A range of m0I/m' is most preferable because the catalyst activity is high relative to the amount of adhesion.

Various methods such as direct current sputtering, high frequency sputtering, and magnetron sputtering can be used to deposit the catalyst material using the sputtering method. , hydrogen, and other non-oxidizing gases are preferred, and large amounts of oxygen, water vapor, carbon dioxide, and the like are not preferred because they reduce the catalytic activity.

When a substrate coated with a catalyst material by such a method constitutes a packaging container, a heat-sensitive, pressure-sensitive, or heat-sensitive pressure-sensitive adhesive layer is coated or laminated as necessary, and then the catalyst material is coated. It is molded into a container such as a bag with the surface facing inside.

Moreover, it may be stored as it is together with the packaged article in a normal packaging container. It is permissible to coat the surface of the catalyst-coated substrate with a thin layer of organic polymer having good gas permeability before it is used as a packaging container.

After a packaged article such as food or precision parts is stored in such a packaging container, a gas that reacts with the harmful gas inside the packaging container or the harmful gas generated from the packaged article is sealed in the packaging container, or the reaction is After the process of enclosing the gas-generating substance within the packaging container, the container must be hermetically sealed.

For example, hydrogen is used as an enclosed gas to remove oxygen from a packaging container in order to prevent corrosion, quality deterioration, rust, etc. due to oxidation. In this case, an amount of hydrogen equivalent to twice the volume of residual oxygen or more is enclosed, but it is also possible to use a mixture of hydrogen and other gases such as nitrogen and carbon dioxide. In the packaging of goods, it is generally recommended that the hydrogen content be
From the viewpoint of safety and workability, it is preferable to use a nitrogen mixed gas of less than % by volume.

In addition, if you use a substance that generates hydrogen slowly at room temperature and pressure, there is no need to add hydrogen gas, which improves workability.
More preferred in terms of safety.

Substances that generate hydrogen include the following metal hydrides, such as lanthanum-nickel, magnesium-nickel, zirconium-iron, zirconium-cobalt, zirconium-chromium, magnesium-copper, and zirconium. There are magnesium hydrides, and among them, those that easily release hydrogen at room temperature and pressure are desirable. By using the packaging article according to the present invention, harmful oxygen gas can easily react with hydrogen even at room temperature by catalytic action and be converted into trace amounts of water, ensuring no quality loss even during long-term storage of the packaging article. It became possible to maintain the condition without any deterioration.

Although the examples of oxygen and hydrogen are shown above, the present invention is not limited to these. The packaged articles according to the present invention include foods such as oil confectionery such as potato chips, gastera, rice crackers, peanuts, kamaboko, chikuwa, dried bonito flakes, cheese, powdered milk, ham sausage, instant noodles, bread, fish, meat, raw vegetables, and fruits; Canned fish and meat, green tea, black tea, coffee, cocoa, sake, wine, whiskey and other beverages, tobacco, various medicines such as vitamins, electrical contact materials, precision tools,
Can be used for packaging precision measuring instruments, etc.

Next, embodiments of the present invention will be described in detail.

EXAMPLE Palladium was deposited by sputtering on an axially stretched polyethylene terephthalate film (Lumira, manufactured by Toray Industries, Inc., thickness: 12 μm).

For sputtering, DC bipolar sputtering was used.
A palladium plate with a width of 400 mm, a length of 200 mm, and a thickness of 1 mm was placed on a water-cooled target holder, and this was used as a cathode so that a voltage of -3 kV could be applied. Width 400m7! The L polyethylene terephthalate film was made to run along a metal water-cooled drum placed opposite the cathode. First, the inside of the vacuum system is evacuated to 5×10-5T0rr, and then the purity is 99.
Fill with 99% dry argon gas and increase the pressure to 7 x 10
While maintaining the voltage at -2T0rr, a voltage was applied to the cathode to generate plasma discharge. Palladium was deposited in various thicknesses on the substrate film while changing the film running speed and applied voltage. When the applied voltage was 3 Kv and the film speed was 10 m/min, a uniform catalyst deposition of 2.5 x 10-4 m01/TI was obtained. A layer was formed. The amount of palladium deposited on the substrate film was actually measured by activation analysis.

On the other hand, as a film with high gas barrier properties, a composition made of polyvinylidene chloride is coated on one side of a polypropylene film, and polyethylene is further laminated on the coated side (total thickness of 50μ), so that the polyethylene side is on the inside. A bag with an internal volume of 500 cc was produced in this manner.

Here, the composition made of polyvinylidene chloride was applied under the following conditions.

Coating agent 1 Krehalon DOATX-27 (vinylidene chloride copolymer manufactured by Kureha Chemical Co., Ltd.) 100 parts by weight in solid quantity 3 Zeon 1211.25 parts by weight (vinyl chloride straight polymer manufactured by Nippon Zeon Co., Ltd.) Zinc stearate 0 Mixed emulsion consisting of .25 parts by weight (concentration: 30% by weight) Coating amount: 19/m゛ (solid content) Drying: 1400C for 4 seconds. Extrusion laminate (approximately 35μ thick) was performed.

Inside this bag, put 100d of palladium-coated film and the detection part of an oxygen concentration meter (Model J Camo V) manufactured by Toshiba Beckman Corporation, and use replacement gas with a hydrogen concentration of 8% by volume and a nitrogen concentration of 92% to remove the internal air. After replacing it, the opening was heat sealed.

Table 1 shows the continuous measurements of the oxygen concentration inside the bag after it was sealed.

Immediately after sealing, the oxygen concentration was 3 to 401) in all cases, but in most of the cases in which the palladium-coated film was sealed, the oxygen concentration decreased to 0.1% or less within one hour. Table 1 also shows the results of making similar bags and measuring the change in oxygen concentration within the container over time using a gas chromatograph instead of an oxygen concentration meter.

Example 2 In the same manner as in Example 1, a film was coated with platinum and rhodium by sputtering.
The oxygen removal effect was investigated using the same method.

The results are shown in Table 2. Although rhodium has slightly higher activity per amount deposited than platinum, both exhibited properties roughly equivalent to those of palladium. Example 3 A palladium film was attached to the film used in Example 1 on a substrate by vacuum evaporation.

Purity 99.9. % palladium plate was heated and vaporized by electron beam heating, and under a pressure of 5 × 10-5 T0rr,
It was adhered to a film substrate placed at a position 25 cTrL from the heating crucible. The amount of palladium deposited was measured by activation analysis. Thereafter, the oxygen concentration inside the bag was measured in the same manner as in Example 1 to examine the oxygen removal effect. FIG. 1 shows the results of examining the temporal change in oxygen concentration in a deposited film (25 samples) having the same deposition amount as the A6.8 sample produced by sputtering in Example 1. At the same deposition amount, internal oxygen could be removed in a shorter time using sputtering.

Example 4 A composition consisting essentially of polyvinylidene chloride was applied to one side of a biaxially stretched polypropylene film (Toray Fan BOl thickness 20 microns) in the same manner as in Example 1, and the coated surface was Then, palladium was sputtered onto the surface of the polyethylene film in the same manner as in Example 1 using a polyethylene laminated film substrate (total thickness of 50 microns).

The film was heat-sealed with the palladium side facing inside to produce a bag with an internal volume of 500 cc. After heat sealing,
As a result of a 180-volume peel test using Tensilon, it was found that 5009/Cr! has no practical problem as long as the amount of catalyst adhesion is 5 x 10-4 m01/Trl or less! It was found that an adhesive force of L or higher was obtained.

Subsequently, gas replacement and airtight sealing were performed in the same manner as in Example 1, and the oxygen concentration was measured. It was found that oxygen could be completely removed in a shorter time than in Example 1.
Those with a palladium coating amount of 5×10-5m01/TI (
sample. The measurement results for 46.26) are shown in Figure 2. Example 5 A biaxially stretched polypropylene layer of 25μ, polybutene-
A uniaxially stretched layer of an equal weight mixture of 1 and polypropylene has a thickness of 5μ
A two-layer laminated composite film was created.

The polypropylene surface of the composite film was subjected to corona discharge treatment in nitrogen gas, and a composition made of polyvinylidene chloride was applied to the treated surface in the same manner as in Example 1. (manufactured by Nippon Ink Co., Ltd.) was applied (coating amount: 3 g/TI). On the other hand, 5 palladium was added to the surface of the polybutene-1 and polypropylene mixture layer of the composite film by the sputtering method as in Example 1.
x10-5m01/TI was deposited. The thus obtained film was heat-sealed with the palladium-attached side facing inside to prepare a packaging bag with an internal volume of 500 cc, and the bag was replaced with gas and hermetically sealed in the same manner as in Example 1, and the oxygen concentration was measured. The oxygen concentration is 3.5% by volume after 0 minutes and is 60
After a few minutes, the concentration decreased to 0.1% by volume or less. Example 6 Palladium was deposited on one side of a biaxially stretched polypropylene film with a thickness of 35 μm by the sputtering method in the same manner as in Example 1.
μ polyethylene was extruded and laminated.

On the other hand, on the other side, an acrylic ester-methacrylic ester copolymer (copolymerization ratio = 99.5:0.
An ethyl acetate solution of a pressure-sensitive adhesive containing 5% by weight) as a main component was applied and dried with hot air at 100°C to evaporate the solvent. The thus produced film was cut into 30 mm x 30 mm pieces (this is referred to as 5 films). On the other hand, heat sealable polypropylene film (manufactured by Toray Industries, Inc., TM2)
In the same manner as in Example 1, a composition consisting of polyvinylidene chloride was applied to the non-heat-sealed surface of the
This is called 8 films). Next, the adhesive surface of the 6th film was attached to a part of the heat-sealed surface of the 8th film other than the heat-sealed portion by pressure bonding so that the adhesive surface of the 6th film was aligned with the heat-sealed surface. Using the thus produced film, a packaging bag with an internal volume of 500 cc was prepared with the heat-sealed surface facing inside, and the bag was heat-sealed, and the oxygen concentration inside the bag was measured in the same manner as in Example 1. As a result, the oxygen concentration of 3.4 volume % immediately after sealing became O volume % after 24 hours. Example 7 Similar to Example 1, palladium was added to a biaxially stretched polyethylene terephthalate film (12 μ) in a 1×1
0-4 m01/ml was deposited.

This was cut into 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 x 30 type sections from this material, respectively, and placed in a 40 mm x 40 mm polyethylene pouch (thickness: 20 µm) and sealed.
The pouch thus obtained was placed in the 8-film packaging bag (inner volume: 500 cc) described in Example 7, heat-sealed, and the oxygen concentration was measured in the same manner as in Example 1. As a result, the oxygen concentration immediately after sealing was 3.5% by volume, but after two days it became O% by volume. Example 9 Biaxially oriented polypropylene film (Trefan BO
An ethyl acetate solution of the adhesive whose main component is the acrylic ester/methacrylic ester copolymer used in Example 7 was applied to the corona discharge treated surface of T253O2Oμ).
The solvent was evaporated to dryness under hot air at 0° C. for 1 minute, and 50 μm aluminum foil was bonded to the adhesive side.

Palladium was applied to the aluminum surface by sputtering.
×10 −4 MOl/7rI was deposited, and then, in the same manner as in Example 1, 40 μm polyethylene was laminated on the palladium-deposited surface. The inner volume of the thus obtained composite laminated film is 500 cc so that the polyethylene surface is on the inside.
A bag was made, heat-sealed, and the oxygen concentration was measured in the same manner as in Example 1. As a result, the oxygen concentration immediately after sealing was 3
．． 6% by volume became 0% by volume after 2 days. Example 10 Put butter peanuts, potato chips, and instant ramen noodles into the film container prepared in Example 4, and after purging with a mixed gas of 8% hydrogen and 92% nitrogen by volume, seal the opening and store in a dark place. It was stored at a constant temperature of 40°C for 90 days.

The peroxide value of the oil used in the food before packaging and after storage was measured for the four samples mentioned above, and the rate of increase in peroxide value was low at 1.5 times or less in all cases.

On the other hand, when a film not coated with palladium was used, the rate of increase in peroxide value was more than four times as high. Example 1
1. Aluminum with a thickness of 800λ was vacuum deposited on a biaxially stretched polyethylene terephthalate film (manufactured by Toray Industries, Inc., mirror 5°, thickness 25 microns), and palladium was applied to the deposited surface in the same manner as in Example 1. I sputtered.

The amount of palladium deposited was adjusted to 2 x 10-4 m01/M°. Furthermore, a film was prepared by laminating polyethylene with a thickness of 25 microns on the palladium layer. That Fuino? A cylindrical bag with a diameter of 607 nm was made using a cylindrical bag, and after storing green tea, coffee, and cocoa respectively inside, the bags were replaced with a mixed gas having a nitrogen concentration of 92% by volume and a hydrogen concentration of 8% by volume. 3. Heat and press the opening.
Seed samples were prepared.

Even after being stored at a constant temperature of 30℃ for 6 months, the fragrance remained unchanged and the product remained as fresh as before packaging.

[Brief explanation of the drawing]

FIG. 1 shows changes in the oxygen concentration in the bag in Examples 1 and 3.

Claims (1)

[Claims] 1. A packaged article in which a thin layer of a catalytic material formed on a substrate by a vacuum deposition method and at least two or more gases that react with each other using the catalytic material as a catalyst coexist inside the package.