JPH06183465A - Sealed container with deoxidizing function - Google Patents

Abstract

PURPOSE:To make it possible to preserve foods and drinks for a long period of tide by storing the foods and drinks which are subject to the influence of oxygen to avoid oxidation and degradation thereof. CONSTITUTION:A container body 2 made from nonmetals such as ceramics and a cover body for sealing the container body 2 are provided, and at least a part of the internal surface of the container body 2 and/or the cover body is covered with a film of metal such as iron or zinc or manganese which is liable to react with oxygen, thereby forming an deoxidizing layer 4. And the layer 4 is covered with a water-holding layer 5 and an oxygen.water-permeable layer 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically sealed container for accommodating food and drink susceptible to oxygen, preventing oxidation and deterioration of the food and drink, and enabling long-term storage thereof.

[0002]

BACKGROUND OF THE INVENTION As is well known, oxygen is a strong oxidant, so if it is enclosed together with food in a container, it oxidizes the food and deteriorates its quality. For example, it is known to promote the sugar-amino reaction, oxidize vitamins and fats, or oxidize and decompose natural pigments and aroma components (Beverage Japan.
n), No. 39, p. 23-35). In addition, it promotes corrosion of the inner surface of the can, causing the dissolution of excessive tin in tin-plated steel sheets,
It causes troubles such as generation of can odor. For example, there is deterioration of beer taste due to excessive residual oxygen in the headspace, black discoloration corrosion of mandarin orange cans, etc. Reduction of this residual oxygen (headspace and dissolved oxygen) has been a long-standing concern in the food industry. It was

Oxygen existing in the container is mainly based on air mixed in when the contents are sealed, and in order to reduce the enclosed amount, (1) the contents are preheated in advance and when heated, Full filling and immediate sealing (fruit juice etc.), (2) encapsulation and heating for deaeration (solid food), (3) method using vacuum wrapping device (vacuum seamer), (4) ) A steam flow seamer method in which pressurized steam is blown into the head space of a can, and (5) a method of sealing while flowing carbon dioxide or nitrogen are available.

Each of these conventional techniques has advantages and disadvantages, but the methods (1) and (2) are specific to the contents to be heat-sterilized, and (3) is a liquid when the amount of contents is large. Is sucked up, so it is limited to foods with little juice.
Since (4) uses steam, it cannot be applied to, for example, beer, carbonated drinks, etc., and (5) has the drawback of high cost.

As described above, it is extremely difficult to completely prevent oxygen from being mixed with air in the container.

Then, as a second best measure, a method of removing oxygen mixed in the container by suction in the container can be considered. As such a removal method, for example, a deoxidizer that absorbs oxygen together with the contents in a closed container (sulfoxylate, reducing organic compounds such as nitrite, iron powder, etc.) is placed in a breathable container, Alternatively, a method of absorbing and removing oxygen in the air in a closed container by wrapping it in a breathable film and putting it in is used.

However, in the above-mentioned method, since a package made of a breathable container or a breathable film containing an oxygen scavenger must be sealed together with the contents, there is a possibility that it may react with the contents. The reality is that it has not been put into practical use for the preservation of liquid food and drink and medicines. Therefore,
If the sealed container can be manufactured from a material having an oxygen scavenging function, it is a very useful oxygen scavenging method because it is easy to handle without the need to prepare a separate oxygen scavenger and can be easily applied to the liquid substance. Will be provided.

Therefore, a hermetically sealed container having a deoxidizing function in which the container itself is made of easily oxidizable iron or the like and has an oxygen absorbing capacity has also been developed.

[0009]

By the way, the above-mentioned conventional sealed container in which the container itself has an oxygen absorption capacity is formed of a metal such as iron which easily oxidizes the container itself as described above, and the corrosion reaction ( There is a problem that the material of the container is extremely limited due to the property of removing oxygen in the container by utilizing the oxidation reaction), and it cannot be applied to a ceramic container.

An object of the present invention is to solve the above-mentioned conventional problems and to make it possible to give an oxygen absorbing capacity to a ceramic container, that is, to provide a sealed container having an oxygen absorbing capacity. It was made as.

[0011]

In a sealed container comprising a container body and a lid for sealing the container body, at least a part of the container inner surface of the container body and / or the lid is
A deoxidized layer was formed by coating with a thin film of a metal such as iron, zinc or manganese that easily reacts with oxygen.

Further, in the above-mentioned sealed container, the deoxidizing layer is covered with a water retaining layer and an oxygen / water permeable membrane layer.

[0013]

The oxygen in the sealed container is absorbed and removed by the oxidation reaction with the deoxidizing layer formed on the inner surface of the container body or the lid.

The water stored in the water retention layer accelerates the oxidation reaction of the deoxygenation layer, and the oxidation products such as rust are trapped by the oxygen / water permeable membrane layer and enclosed in the container. It is possible to prevent the product from being mixed.

[0015]

The present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a hermetically sealed container having a deoxidizing function according to the present invention. The container 1 is a container body 2 made of ceramics.
And a lid 3 for sealing the container body 2,
Alcoholic drinks such as sake and western sake are enclosed inside.

A deoxidizing layer 4 is formed on a part of the inner surface of the container body 2 as shown in FIG. 2, and a water retaining layer 5 and oxygen / water are provided so as to cover the deoxidizing layer 4. The permeable membrane layer 6 is formed.

The deoxidizing layer 4 is formed by coating a metal such as iron, zinc or manganese, which easily reacts with oxygen, by vacuum vapor deposition, ion plating, sputtering or the like so that the inner surface of the container body 2 is very thin. It is formed by doing.

The thickness of the deoxidizing layer 4 is determined by the absolute amount of oxygen contained in the content and the inner area of the deoxidizing layer 4, and as an example, the content volume is 100 ml and the dissolved oxygen amount is 0.5 ppm. The required thickness of the deoxidizing layer 4 is calculated by the following formula, taking as an example the case where the deoxidizing layer 4 is formed of iron with the inner area of the deoxidizing layer 4 in contact with the contents being 100 cm ² .

The _{4Fe + 30 2 + H 2 O} → 2Fe 2 O 3 · H 2 O ( ^{_{rust) 0.5 X 10 -3 (100/1000)}} X (4 X 55.85
/ Becomes _{3 X 32) = 1.16 X 10} -4 g = 0.116mg and may be only about 0.12 mg. When the density of iron is set to 7.85 g / cm ² and converted to thickness, it corresponds to only about 15 Å, and it can be seen that an extremely thin coating has a sufficient oxygen absorption capacity.

When zinc or manganese is used as the material of the deoxidizing layer 4, the reaction formula is different, but the amount is almost the same as that of iron.

The amount of iron, zinc, manganese, etc., need not be strictly regulated, but it is meaningless to deposit more than the amount required for oxygen removal, and the excess amount is at least corrosion in the container. Therefore, the minimum amount should be applied according to the amount of oxygen normally enclosed in the target container.

The vacuum deposition here means from 10 ^-2 to 10
^-5 is a normal method of evaporating and adhering molten metal in a vacuum of about ^-5 Torr, and ion plating is a method of applying a DC voltage (or superposing a high frequency wave) to an object to be coated in vacuum evaporation. is there. Similarly, the sputtering is performed in a vacuum of about 10 ⁻³ Torr (including a small amount of Ar gas), and the target and the target metal (Fe, Zn, M
n, Mg, etc.), a voltage of several hundreds of volts is applied to generate argon plasma, whereby the target metal is made into atoms or ions and attached to the surface of the object.

A water-soluble polymer is used as the hydrophilic substance in the water retaining layer 5. This includes starch,
Natural substances such as gelatin and casein, methyl cellulose,
Cellulose derivatives such as ethyl cellulose, carboxymethyl cellulose and hydroxyethyl cellulose, vinyl polymers such as polyvinyl alcohol, polyvinyl methyl ether and polyvinyl pyrrolidone, and synthetic polymers such as acrylic acid, methacrylic acid, and their esters are used. Compounds are desirable. The water-soluble compound is coated as an aqueous solution by a spray, a roll coater or the like. Further, it is heated and dried if necessary. Coating thickness is usually 0.1-0.5
It is about μm.

The oxygen / water permeable membrane layer 6 has an oxygen permeability coefficient of 10 ^-10 cm ³ . cm / cm ² · sec. cm
There is no particular need to limit the type as long as it is Hg or higher. This is because the permeation rate of water in an ordinary polymer membrane is remarkably faster than that of oxygen, and the reaction is rate-controlled by diffusion of oxygen. Substances preferably used for this purpose include polyolefin compounds such as polyethylene, polymethylpentene and polybutadiene, and silicone paints such as polymethylsiloxane. These are formed into a sheet and coated by thermocompression bonding or an adhesive, or by dissolving in an organic solvent and spray coating. Coating thickness is 5μm to 3
The thickness is 00 μm, usually 20 to 50 μm. When an adhesive is used, it is generally applied in the form of a polyester type, a polyurethane type, a polyacrylate type, a modified vinyl type or a modified olefin type, or a mixture thereof. If necessary, polyisocyanate, phenol resin, epoxy resin, amine compound, etc. may be added appropriately.

Experimental Example 1 A ceramic (pottery) bottle (internal volume: 750 ml) was coated with zinc on its inner surface by a vacuum deposition method to a thickness of about 30 Å. The zinc vapor was vaporized and supplied by heating the granular zinc in the water-cooled copper crucible installed in the vacuum container with a heater and melting it. The degree of vacuum at this time is 10 ^-4 Torr
Met. Since zinc is vapor-deposited only on the inner surface of multiple bottles at a time, a plurality of holes with a diameter approximately equal to the bottle diameter should be opened in the support substrate installed above the evaporation source, and the bolts should be placed upside down. Deposition was performed by. The vapor deposition time is about 10 seconds. In order to prevent the metal from remelting in the content after vapor deposition, silicon coating of 10μ is used as an oxygen / water permeable membrane layer as an organic coating with good oxygen / water permeability.
It was spray painted to the thickness of.

Beer containing 0.6 ppm of dissolved oxygen was filled in the container and the container was tightly closed. After standing at room temperature for 24 hours, O ₂ in the beer was measured using a dissolved oxygen meter, and the value was 0.06 ppm, which was about 1/10 that of the beer. On the other hand, in a normal container without metal coating, the value was only 0.3 ppm, and a remarkable deoxidizing effect was recognized in the container according to the present invention.

Experimental Example 2 On the inner surface of a ceramic bottle (internal volume: 750 ml),
Approximately 30Å of iron by the ordinary ion plating method
Coated. In order to coat only the inner surface, a substrate provided with a hole having the same diameter as the bolt to be coated was used as the counter electrode. The bottle was installed upside down at the position of this hole so that metal ions could be supplied from below through this hole. Iron as an evaporating metal was prepared in a water-cooled copper crucible and irradiated with an electron beam of 10 KV and 100 mA using a hollow cathode electron gun to melt and evaporate. The vaporized iron dissociates the electrons into positive ions when passing through the electron beam, while the substrate applies a DC voltage of -200 V to the ground, so the iron ions are on the inner surface of the bottle on the substrate. Is deposited on. The degree of vacuum in the apparatus is 10 ⁻⁴ Torr, and the coating time is 15 seconds.

Silicone paint is spray-coated in this container in the same manner as in Experimental Example 1. Similarly, beer having 0.6 ppm of dissolved O ₂ was filled. The amount of dissolved O ₂ after standing at room temperature for 24 hours was 0.04 ppm, and a remarkable deoxidizing effect was recognized.

[0030]

According to the present invention, the oxygen in the sealed container is
It is absorbed and removed by an oxidation reaction with a deoxidizing layer formed on the inner surface of the container body or the lid.

The moisture stored in the water retention layer accelerates the oxidation reaction of the deoxygenation layer, and oxidation products such as rust are trapped by the oxygen / water permeable membrane layer and sealed in the container. It is possible to prevent the product from being mixed.

[Brief description of drawings]

FIG. 1 is a perspective view of a sealed container having a deoxidizing function according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sealed container, 2 ... Container body, 3 ... Lid body, 4 ... Deoxidization layer, 5 ... Water retention layer, 6 ... Oxygen / water permeable membrane layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsunetoshi Asai 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Stock Co., Ltd.

Claims (2)

[Claims] 1. A container main body and a lid for sealing the container main body, wherein at least a part of the inner surface of the container main body and / or the lid is reacted with oxygen such as iron, zinc or manganese. A sealed container having a deoxidizing function, characterized in that a deoxidizing layer is formed by coating with a metal thin film that is easy to perform. 2. The sealed container having a deoxidizing function according to claim 1, wherein the deoxidizing layer is covered with a water retaining layer and an oxygen / water permeable layer.