JP2002020746A - Magnesium-based oxygen scavenger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stabilized oxygen scavenger with activated magnesium as the main agent, free from risk of heat generation even in air, and substantially free from loss of its initial oxygen-absorbing activity. SOLUTION: This stabilized oxygen scavenger is obtained by treating zeolite selected as the magnesium carrier with carbon dioxide. Another version of this oxygen scavenger having high oxygen-absorbing activity is obtained by activating the above scavenger through contacting it with moisture or a highly humid atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a non-ferrous oxygen scavenger. More specifically, the present invention relates to a method for producing a stabilized oxygen scavenger and a method for activating oxygen absorption activity, which mainly use activated magnesium supported on a zeolite carrier.

[0002]

2. Description of the Related Art Recently, a storage method using various oxygen absorbers has been developed as a method for storing articles in a sealed package, and has attracted attention as an inexpensive and reliable storage method. Various organic and inorganic base oxygen scavengers have been known. For example, inorganic powders such as metal powders such as iron powder, sulfites, bisulfites, dithionites, thiosulfates, etc., and L-ascorbic acid, ersorbic acid and salts thereof as organic bases. And reducing sugars such as glucose, catechol and pyrogallol, and polyhydric alcohols such as ethylene glycol and glycerin.

[0003] Furthermore, among the oxygen scavengers of the inorganic main agent, there is a problem that the iron powder scavenger cannot be inspected for metal in a state of being enclosed with an article such as food because it is sensitive to a metal detector.

The present inventor has found an oxygen scavenger containing activated magnesium supported on a carrier as a main component, and has previously proposed it (Japanese Patent Application No. 11-212749). Activated magnesium is very liable to be oxidized in air and has a risk of heat generation, so that it is necessary to perform a stabilization treatment in order to make it a practical oxygen absorber.

On the other hand, the following stabilization methods have been proposed as methods for safely handling activated metal catalysts that are unstable in the air. (1) A method in which, after activation, an inert gas is flowed under heating or decompression and vacuum treatment under heating to stabilize. (2) A method in which, after activation, a small amount of oxygen is gradually added to an inert gas, and finally the mixture is stabilized under a stream of air only.

[0006] Regarding the method (1), for example, in US Patent No. 1001279, nickel oxide or a nickel compound supported on a refractory brick is heated and reduced with hydrogen, and then carbon dioxide gas is flow-treated under heating. Stabilization method of cooling to room temperature with carbon dioxide gas. US Pat. No. 1,279,911 discloses a method in which fine metal powder such as nickel, cobalt, and platinum or a metal compound or a mixture thereof supported on a carrier such as silica gel is reduced by heating with hydrogen. Thereafter, a method of stabilizing by reducing the pressure and the vacuum while heating is described.
JP-B-33-4325 discloses that a nickel compound supported on diatomaceous earth is reduced by heating with hydrogen, or nickel formate is thermally decomposed and activated, and then carbon dioxide gas or nitrogen is passed under heating. Stabilization method, Japanese Patent Publication No. 34-2570
The publication discloses that a catalyst, an oxide, or a sulfide containing platinum, palladium, gold, copper, iron, or cobalt metal alone or as a main component is reduced by heating with hydrogen, and then decompressed and vacuum-treated, and then stored in carbon dioxide gas. A method for stabilizing by storing over time is described. However, all of these stabilization methods have many problems such as insufficient stability in air, and a significant decrease in activity during stabilization, and in some cases, loss of activity itself. Furthermore, in order to activate the stabilized catalyst activity,
There is no other method than reducing the hydrogen again under heating, and it cannot be said that it is an easy and practical method for controlling the catalytic activity.

For the method (2), for example, Catal
ytic Reactions at High Pressures and Temparatures,
In New York and Macmillan, 1936, after reducing basic nickel carbonate supported on diatomaceous earth with hydrogen, an inert gas such as nitrogen or carbon dioxide was passed under heating, and oxygen was gradually mixed with this gas. The method of stabilizing with a mixed gas described above, and the improved methods of this method, JP-B-31-4368 and JP-B-26-871, describe a stabilization method of finally treating with only oxygen gas. . However, any of these methods has a problem in that the oxygen absorption activity used in the stabilization deactivates the oxygen absorption activity and the initial activity cannot be maintained. Furthermore, in order to activate the activity, it is necessary to perform heat reduction again in order to remove the oxidation protection film formed during the stabilization. .

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to deal with the danger of generating heat over a long period of time in air and with little loss of the initial activity of oxygen absorption. Method for producing a non-ferrous stabilized oxygen scavenger that is industrially easy to carry out, a method for easily reactivating the stabilized oxygen absorption activity (deoxidation ability), and activation of the oxygen absorption activity To provide an improved oxygen absorber.

[0009]

As a result of studying a method for solving the above-mentioned problems, the present inventor has selected zeolite as a carrier in a deoxidizer containing activated magnesium as a main component, and selected an inert catalyst. A deoxidizer stabilized by a stabilization method / process characterized by treating with a carbon dioxide gas contained as a gas; and an easy-to-activate characterized by exposing this to a high moisture or high humidity atmosphere to activate it. The present inventors have found a practical method for controlling oxygen absorption activity (deoxygenation ability), and have completed the present invention.

That is, the present invention provides a stabilized deoxygenating agent by a stabilizing method and step, wherein a magnesium compound supported on a zeolite carrier is reduced and activated, and then subjected to a stabilizing treatment with carbon dioxide gas. The present invention relates to a production method and a method for producing a stabilized oxygen scavenger or a method for controlling the oxygen scavenging capacity, which further comprises an activation treatment with steam after the stabilization treatment.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, it is important to select zeolite as a carrier. That is, a combination of magnesium and a zeolite carrier is essential. Although the detailed reason is not always clear, the pore structure of the zeolite carrier, the surface properties are suitable for occluding and adsorbing acidic carbon dioxide gas, and the affinity between activated activated magnesium and carbon dioxide gas It may be in a state of raising.

The activated magnesium of the present invention is obtained by reducing and activating a magnesium compound supported on a carrier. In the present invention, the activated magnesium is used as a main component. The main agent is a component that reacts with and absorbs oxygen. In the present invention, oxygen is absorbed only by the main agent, but if necessary, an auxiliary agent can be combined with the zeolite carrier supporting magnesium separately. Any auxiliary agent can be used without particular limitation as long as it has no problem in safety and promotes oxygen absorption without obstructing the object of the present invention such as not being detected by a metal detector. For example, activated carbon, diatomaceous earth, acid clay, alumina, silica, and titania are exemplified.

The activated magnesium used in the present invention is obtained by carrying out a reduction treatment after supporting a magnesium compound such as an inorganic salt or an organic salt of magnesium on a carrier. As the inorganic salt compound of magnesium, for example, magnesium sulfate, nitrate, hydrochloride, carbonate and the like are used. As the organic salt compound of magnesium, for example, formate, acetate, oxalate and the like of magnesium are used.

The loading of activated magnesium, ie,
The weight% of the magnesium amount with respect to the total of the magnesium amount (converted value of magnesium element) and the carrier amount (converted value in dry state) is usually 5 to 90% by weight. In particular, the time required for activation and the activation efficiency are in the range of 30 to 80.
% By weight is preferred.

[0015] The zeolite carrier used in the present invention may be a natural product or a synthetic product, and may be in any form of granules or powder, and is not particularly limited. The magnesium compound is supported on the zeolite carrier by a known chemical method such as an impregnation method or a coprecipitation method. In addition, it can be supported by a physical method such as ion implantation.

In particular, the oxygen scavenger composition of the present invention is preferable when it does not substantially contain a magnetic substance, because the oxygen scavenger composition is not detected by a metal detector. For this reason, it is preferable to use a carrier substantially free of a magnetic substance.

As the form of the carrier on which the magnesium compound is carried during activation, the activation may be carried out in any form of granular or powder. Alternatively, activation may be performed after molding by a normal molding method such as pressure molding or extrusion molding.

The magnesium compound supported on the zeolite carrier is activated with a reducing agent. There is no limitation on the reducing agent, and either an organic substance or an inorganic substance can be used. Examples of the method for activating magnesium in the present invention include a chemical reduction method using a reducing compound such as formalin and formic acid, and a catalytic reduction method using a reducing gas such as carbon monoxide and hydrogen. Further, a method of thermally decomposing a decomposable magnesium compound such as magnesium formate in an inert gas or in a reducing gas such as carbon monoxide or hydrogen is also used.

The activating conditions in the present invention are as follows.
Although it depends on the amount of the carrier and the treatment method and cannot be unambiguously determined, in the catalytic reduction method, the reducing atmosphere temperature is usually 100 ° C. to 800 ° C. for 10 minutes to 10 hours, particularly 200 minutes.
C. to 600.degree. C. for 30 minutes to 6 hours are suitably used. By this series of reduction operations, an oxygen scavenger carrying so-called activated magnesium metal fine particles active against the oxygen absorption reaction is obtained.

The oxygen scavenger obtained here has an extremely high oxygen absorbing activity (hereinafter also referred to as "initial activity"). On the other hand, because of its high oxygen absorption activity, there is a danger of heat generation due to contact with air during handling. In the present invention, the zeolite carrier supporting the magnesium compound is subjected to an activation treatment with a reducing agent and then to a stabilization treatment for controlling the activity with carbon dioxide.

The carbon dioxide gas used in the stabilization treatment of the present invention is a carbon dioxide gas containing carbon dioxide as a component. For example, nitrogen and a rare gas such as carbon dioxide, helium, neon, or argon and carbon dioxide are used. Mixed gas or carbon dioxide gas alone. In the carbon dioxide gas containing carbon dioxide gas, the effect of stabilizing activated magnesium is higher as the content ratio of carbon dioxide gas is larger. As a carbon dioxide gas supply source, a gas cylinder of normal purity or dry ice is preferably used, but the use of carbon dioxide gas of higher purity is more preferable. In addition, the stabilization method may be a standing method in which a zeolite carrier carrying a magnesium compound is left in an atmosphere in which carbon dioxide gas is present in an amount of 10 ml or more per 1 g of magnesium, or a method in which a zeolite carrier carrying a magnesium compound is carried out per 1 g of magnesium. Any method of a flow method in which a gas is contacted at a flow rate of 5 ml / min or more can be used.

In the case of the stationary method, 1 g of the activated oxygen scavenger is usually added to 10 g, although it depends on the purity of the carbon dioxide contained.
In 10% or more, preferably 50ml or more, more preferably 100ml or more carbon dioxide gas for 5 minutes to 10 hours at a temperature of -10 ° C or more, preferably 0 to 80 ° C or more, more preferably 0 to 80% in terms of 0% containing carbon dioxide gas. What is necessary is just to leave still in the range of 0-30 degreeC. In the case of the flow method, a flow rate of carbon dioxide gas is usually 5 ml / min or more, preferably 50 ml or more, more preferably 100 ml or more, and the temperature is -10 g / g of the activated oxygen scavenger in terms of 100% containing carbon dioxide. ° C
Or more, preferably 0 to 80 ° C. or more, more preferably 0 to 80 ° C.
The treatment may be performed at 30 ° C. for about 5 minutes to 6 hours.
From the viewpoint of processing efficiency, the carbon dioxide gas flow rate is 100 to 300 ml /
Processing conditions of about 30 minutes to 3 hours at 0 to 30 ° C. are preferably used.

Further, in order to further enhance the stabilizing effect, it is preferable to perform deaeration by depressurization or vacuum operation immediately after the activation before performing the above-mentioned carbon dioxide treatment. For example, after the activation is completed, a vacuum is once applied, and the activated hydrogen gas absorbed and occluded by the activated magnesium is removed to remove the remaining activated hydrogen gas, thereby completely eliminating the danger of heat generation. By performing the gas treatment, the oxygen scavenger can be more safely and effectively stabilized.

Thus, the activated magnesium deoxidizer supported on the stabilized zeolite no longer has the danger of heat generation for a long time even when taken out into the air, and the initial oxygen absorption activity is reduced. No, it can be safely handled in the air.

In the present invention, the oxygen scavenger stabilized in the carbon dioxide gas treatment step can easily activate the oxygen absorbing activity by performing a treatment for providing moisture. The activation treatment with water is performed by leaving the oxygen scavenger that has been subjected to the stabilization treatment with carbon dioxide gas in an atmosphere having a humidity of 60% RH or more. Or,
It is carried out by adding water to the stabilized oxygen scavenger. It is performed by mixing with a carrier containing water.

The activation rate increases as the humidity or the amount of water increases. Usually, the deoxidizing agent consisting of a zeolite carrier carrying a magnesium compound stabilized by carbon dioxide is used at 10 to 80 ° C., preferably 20 to 80 ° C. ~ 40
Humidity of 60% RH or more, preferably 80% RH in the range of ° C
It can be activated by exposure to the above humidity atmosphere for 10 minutes or more.

Alternatively, 1 to 100 mg of water is added to or mixed with 1 g of the zeolite carrier supporting the magnesium compound stabilized by carbon dioxide. By this activation treatment, the oxygen absorbing activity of the oxygen absorber composed of the zeolite carrier supporting the stabilized magnesium compound is activated. A water-containing zeolite, diatomaceous earth, acid clay, alumina, silica, titania, activated carbon, or the like may be blended as a moisture donor.

If the storage product has a high water activity and the activating moisture condition can be easily achieved, the water vapor generated from the storage product without adding water or the water vapor enclosed with the storage product is used. be able to. For example, a zeolite carrier carrying a stabilized magnesium compound may be activated by sealing it in an oxygen-barrier container together with a preservation article and placing it in an atmosphere of 60% RH or more, preferably 80% RH or more. it can.
Therefore, by combining the stabilization treatment step by the treatment with the carbon dioxide gas and the activation step of the stabilizing oxygen absorber by the treatment with moisture or humidity atmosphere, the oxygen absorption can be easily performed without almost losing the initial activity before the stabilization treatment. Activity (deoxygenation ability) can be controlled.

As the material of the oxygen barrier container for sealing the oxygen absorber together with the storage article, known oxygen barrier materials can be used, but ethylene-vinyl alcohol copolymer, MX nylon, vinyl chloride is preferable. A laminated resin material having an oxygen barrier resin layer such as vinylidene chloride is used.

The stabilized oxygen absorber of the present invention can be used as a small bag-shaped oxygen absorber by storing it in a small bag having a suitable air permeability. Also, by blending the stabilized oxygen absorber of the present invention into a resin or a sheet, it can be used as an oxygen absorber of any form such as a sheet oxygen absorber. The stabilized oxygen absorber of the present invention is preferably combined with a carbon dioxide absorbent such as calcium oxide or calcium hydroxide.

[0031]

The present invention will be described below with reference to examples.

Example 1 49.3 g of magnesium sulfate heptahydrate was added to 60 ° C. water 1
The solution was dissolved in 50 ml, and 20 g of zeolite was added and mixed with stirring. Next, 31.8 g of anhydrous sodium carbonate was added to water 2
An aqueous solution dissolved in 00 ml was added dropwise,
Stirred for 0 minutes. After completion, the insolubles were collected by filtration, washed with water until the filtrate became neutral, and dried at 110 ° C. 0.5 g was collected from the obtained dry powder to obtain 300 kg / cm ² ,
Pressure molding was performed under the condition of 3 minutes to prepare a disc-shaped molded body having a diameter of 12 mm. The two molded bodies thus prepared were placed in a small petri dish made of quartz with a lid of aluminum mesh, pre-heated at 200 ° C. for 30 minutes in a nitrogen stream, and then heated at 450 ° C. in a hydrogen stream.
An activation treatment of reducing at 3 ° C. for 3 hours was performed. After completion of reduction,
After cooling to 40 ° C. while flowing nitrogen, a stabilization treatment was performed in which carbon dioxide gas having a purity of 99% was flowed at a flow rate of 160 ml / min for 1 hour from a commercial cylinder in place of nitrogen gas.
A stabilized oxygen scavenger consisting of a molded body mainly composed of activated magnesium supported on a zeolite carrier was obtained. The obtained stabilized oxygen scavenger contained 36% by weight of magnesium, and the other composition was almost zeolite.

A stabilized deoxidizer made of a molded body mainly composed of activated magnesium supported on a zeolite carrier treated with carbon dioxide is put into a small Petri dish with an aluminum mesh lid in air at a temperature of 20 ° C. and a humidity of 55% RH. It was taken out and left for 1 hour. During that time, no fever occurred. Next, the molded body mainly composed of activated magnesium supported on a zeolite carrier left in the air is put in an oxygen barrier KON / LDPE (vinylidene chloride coated nylon / low density polyethylene film) packaging bag together with water-containing cotton. Then, 500 ml of air having the same temperature and humidity was charged therein, and the oxygen concentration in the bag was analyzed continuously for 24 hours. No change was found in the oxygen concentration. Then, 1 ml of water was added to this package (package bag + oxygen scavenger is referred to as "package"), the atmosphere conditions were set to a humidity of 95% RH, and the oxygen concentration in the bag over time at 20 ° C. And the humidity was analyzed. The results are shown in Table 1.

Example 2 In the same manner as in Example 1, molding, reduction and nitrogen flow were performed to obtain a deoxidizing agent consisting of a molded body mainly composed of activated magnesium supported on a zeolite carrier. After being taken out into a glove box, and then transferred to a side box having a capacity of 1 L and subjected to deaeration by vacuum, 6 hours at 20 ° C. in a carbon dioxide gas atmosphere containing 80% carbon dioxide and 20% nitrogen at 1 atm. The mixture was allowed to stand and subjected to a stabilization treatment using carbon dioxide gas. Thereafter, the molded body stabilized with carbon dioxide gas together with the small petri dish with an aluminum mesh lid was taken out in air at a temperature of 25 ° C. and a humidity of 50% RH in the same manner as in Example 1, and allowed to stand for 1 hour. Did not. Next, the stabilized molded body left in the air in the same manner as in Example 1 was washed with cotton containing an aqueous glycerin solution and 25 ° C., 50%
Immediately oxygen barrier KO with 500 ml of RH air
The bag was placed in an N / PE packaging bag, the atmosphere was set to an atmosphere condition of 80% RH, and the oxygen concentration and humidity in the bag were analyzed over time at 25 ° C. The results are shown in Table 1.

Comparative Example 1 After molding and reduction in the same manner as in Example 1, the mixture was cooled to room temperature by flowing nitrogen. After cooling, the oxygen scavenger containing activated magnesium as the main component supported on the carrier is not subjected to stabilization treatment with carbon dioxide gas, and the same small petri dish with an aluminum mesh lid is kept at 20 ° C. and 55% humidity in the same manner as in Example 1. When taken out in the air of RH and left for 1 hour, about 30 seconds after taking out, severe heat generation occurred, and this phenomenon continued for several minutes, and after about 10 minutes, the temperature was lowered to room temperature of 20 ° C. like this,
After leaving it in the air for 1 hour, it was put in a KON / PE packaging bag together with 500 ml of air as in Example 1, and the oxygen concentration in the bag was changed over time at 20 ° C. under an atmosphere condition of a humidity of 95% RH. And the humidity was analyzed. As a result, almost no change was observed in the oxygen concentration and humidity even after 24 hours. Then, as in the case of Example 1, the package was further filled with water.
5 ml was injected, and the oxygen concentration and humidity in the bag were analyzed over time. The results are shown in Table 1.

Control Example 1 An activated product in a small Petri dish with an aluminum mesh lid was obtained by molding, reducing, and circulating nitrogen in the same manner as in Example 1. The activated product was put together with a small petri dish with an aluminum mesh lid into a paper pouch laminated with perforated polyethylene in a nitrogen atmosphere. The paper bag and the absorbent cotton containing 0.5 g of water were placed in a KON / PE packaging bag, and 500 ml of air was charged into the bag in the same manner as in Example 1 to analyze the oxygen concentration and humidity in the bag over time. The results are shown in Table 1.

Example 3 In the same manner as in Example 1, two stabilized oxygen scavengers were obtained. This was left in air of 55% RH for 24 hours to confirm that no heat was generated. Then, it was placed in a paper pouch laminated with perforated polyethylene on the inside together with 2 g of diatomaceous earth containing 50% by weight of saturated saline, and heated. Sealing was performed to obtain a pouch-shaped oxygen absorber. Immediately put the obtained pouch-shaped oxygen absorber in a humidity of 55%.
Put in 500 ml of RH air into oxygen barrier packaging bag consisting of polyethylene terephthalate / ethylene-vinyl alcohol copolymer / low density polyethylene laminated film, analyze the oxygen concentration in bag over time at 20 ° C. The amount of oxygen absorbed per gram was determined. The results are shown in Table 1.

[0038]

[Table 1]

As can be seen from Table 1, the oxygen scavenger containing activated magnesium supported on zeolite as a main component can generate heat even if it is taken out into the air by flowing treatment with carbon dioxide gas or by leaving it to stand. There is no danger, stabilization can be performed for a long time, and the initial oxygen absorption activity before stabilization does not decrease. Furthermore, the stabilized oxygen absorbing activity can be activated at a moderate rate by treating in a moderate moisture and humidity atmosphere.

Example 4 The stabilized oxygen scavenger obtained in the same manner as in Example 1 was allowed to stand in air at a temperature of 20 ° C. and a humidity of 55% RH for 1 hour to confirm that no heat was generated. Oxygen barrier KO with water-containing cotton and 500 ml of air at 75% RH
Put immediately in a packaging bag made of N / LDPE laminated film, seal immediately, and in an atmosphere condition of 20 ° C. and 75% RH,
The oxygen concentration and humidity in the bag were analyzed over time. The results are shown in Table 2.

Comparative Examples 2, 3, 4, 5 Each of the carriers carrying activated magnesium was prepared in the same manner as in Example 1 except that diatomaceous earth, alumina, titania or acid clay was used instead of the carrier zeolite. Thereafter, the activation treatment was performed by reducing and circulating nitrogen, and then the stabilizing treatment was performed in which carbon dioxide gas was circulated at a flow rate of 160 ml / min. This stabilized product was treated at a temperature of 20 ° C.
When it was taken out into the air having a humidity of 55% RH, about 30 seconds after the taking out, severe heat generation occurred, and this phenomenon continued for several minutes, and after about 10 minutes, it cooled to room temperature of 20 ° C. After leaving it in the air for 1 hour, put it in an oxygen-barrier KON / LDPE packaging bag together with 500 ml of cotton containing saline and 500% of humidity as in Example 4 to obtain a humidity of 75% RH.
The oxygen concentration and the humidity in the bag were analyzed over time at 20 ° C. under the atmosphere conditions described above. The results are shown in Table 2.

[0042]

[Table 2]

As is evident from Table 2, a remarkably effective stabilizing effect by the treatment with the carbon dioxide gas cannot be realized with a carrier other than zeolite. That is, the oxygen scavenger containing activated magnesium as a main component can stabilize oxygen absorption activity in air by selecting zeolite as a carrier and treating it with carbon dioxide after activation.

Example 5 A molded article 4 of a zeolite carrier carrying activated magnesium and treated with carbon dioxide obtained in the same manner as in Example 1
The individual pieces were taken out into air at a humidity of 50% RH, placed in a gas-permeable small bag made of a paper / polyethylene nonwoven laminated film, and heat-sealed to obtain a small bag-shaped oxygen absorber. The oxygen sacrificial oxygen absorber PET / ethylene-vinyl alcohol copolymer /
It was placed in a packaging bag made of a linear low-density polyethylene laminated film and stored at 20 ° C. and 98% RH. The appearance and taste of the cut rice cake were well maintained after 10 days.

Example 6 Two disk-shaped molded bodies obtained in the same manner as in Example 1 were placed in a small quartz dish with an aluminum mesh lid, and preliminarily heated at 200 ° C. for 30 minutes in a nitrogen stream. Thereafter, activation was carried out with a reducing agent by reducing at 550 ° C. for 3 hours in a formaldehyde stream. After completion of the reduction, the mixture was cooled to 30 ° C. while flowing nitrogen, and then a 99% pure carbon dioxide gas from a commercial cylinder was supplied at a flow rate of 100 m instead of nitrogen gas.
By flowing at 1 / min for 1 hour, a stabilization treatment with carbon dioxide gas was performed to obtain an oxygen scavenger composed of a molded body mainly composed of activated magnesium supported on a zeolite carrier.

The two oxygen scavengers thus obtained were subjected to a humidity of 50% RH.
0.1g per piece of saturated saline solution
Immediately after the impregnation, it was placed in a gas-permeable small bag composed of perforated PET / Japanese paper / perforated polyethylene laminated film and heat-sealed to obtain a small bag-shaped oxygen absorber. This sachet-shaped oxygen absorber is put together with salami cheese and 500 ml of air into a packaging bag composed of PET / vapor-deposited silica / low-density polyethylene laminated film having oxygen barrier properties, sealed and sealed at 25 ° C. and 75% R.
Stored under H conditions. The appearance and taste of the salami cheese were maintained well after March.

[0047]

The oxygen absorber based on activated magnesium produced by the method of the present invention can stabilize oxygen absorption activity in air. Further, the stabilized oxygen absorbing activity can be activated by treating in a high moisture or high humidity atmosphere, and the oxygen absorbing activity can be easily controlled by a combination of the stabilizing step and the activating step. The stabilized magnesium deoxidizer produced by the method of the present invention is used as a deoxidizing agent for a moisture-dependent or self-reactive pouch-shaped or sheet-shaped deoxidizer that is not detected by a metal detector. Can be used.

[Procedure amendment]

[Submission date] July 18, 2000 (2007.1.
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction contents]

A stabilized deoxidizer made of a molded body mainly composed of activated magnesium supported on a zeolite carrier treated with carbon dioxide is put into a small Petri dish with an aluminum mesh lid in air at a temperature of 20 ° C. and a humidity of 55% RH. It was taken out and left for 1 hour. During that time, no fever occurred. Next, a molded body mainly composed of activated magnesium supported on a zeolite carrier left in the air was subjected to oxygen barrier KON / LD.
Put into a PE (vinylidene chloride-coated nylon / low-density polyethylene film) packaging bag, charge 500 ml of air at the same temperature and humidity, and analyze the oxygen concentration in the bag over time for 24 hours. I couldn't. Then, 1 ml of water was added to the package (the package + the oxygen scavenger is referred to as “package”) and the humidity was 95% RH.
The oxygen concentration and the humidity in the bag were analyzed over time at 20 ° C. under the atmosphere conditions described above. The results are shown in Table 1.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction contents]

Comparative Example 1 After molding and reduction in the same manner as in Example 1, the mixture was cooled to room temperature by flowing nitrogen. After cooling, the oxygen scavenger containing activated magnesium as the main component supported on the carrier is not subjected to stabilization treatment with carbon dioxide gas, and the same small petri dish with an aluminum mesh lid is kept at 20 ° C. and 55% humidity in the same manner as in Example 1. When taken out in the air of RH and left for 1 hour, about 30 seconds after taking out, severe heat generation occurred, and this phenomenon continued for several minutes, and after about 10 minutes, the temperature was lowered to room temperature of 20 ° C. like this,
After leaving it in the air for one hour, it was put into a KON / PE packaging bag together with 500 ml of air as in Example 1, and
The oxygen concentration and humidity in the bag were analyzed with time at ° C. As a result, almost no change was observed in the oxygen concentration and humidity even after 24 hours. Then, as in Example 1, 0.5 ml of water was injected into this package, and the oxygen concentration and humidity in the bag were analyzed over time. The results are shown in Table 1.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction contents]

Example 4 The stabilized oxygen scavenger obtained in the same manner as in Example 1 was allowed to stand in air at a temperature of 20 ° C. and a humidity of 55% RH for 1 hour to confirm that no heat was generated. Oxygen barrier KON / LDPE with water containing cotton and same air 500ml
Immediately seal in a packaging bag made of a laminated film,
The oxygen concentration and humidity in the bag were analyzed over time under an atmosphere condition of 0 ° C. and a humidity of 75% RH. The results are shown in Table 2.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B65D 81/26 B65D 81/26 R F-term (Reference) 3E067 AA05 AB97 BA12A BB14A CA06 EE25 EE28 FA04 GB13 4B021 LA16 LW04 MC04 MK08 MP07 4D020 AA02 BA01 BA30 BB01 CA04 DA03 DB01 DB03 4G066 AA16A AA16B AA43A AA47A AA53A AA61C AB07A BA09 CA37 DA20 EA07 FA03 FA15 FA18 FA21 FA25 FA37 4H025 AA01 AB02 AC06

Claims (7)

[Claims] 1. A method for producing an oxygen scavenger, comprising: carrying a magnesium compound on a zeolite carrier, activating with a reducing agent, and then stabilizing with a carbon dioxide gas. 2. The stabilization treatment with carbon dioxide gas is carried out at a rate of 1 carbon dioxide per 1 g of magnesium supported on a zeolite carrier.
2. The method for producing an oxygen scavenger according to claim 1, wherein the method is carried out by allowing to stand in an atmosphere having 0 ml or more. 3. The stabilization treatment with carbon dioxide gas is performed by adding 5 carbon dioxide gas per gram of magnesium supported on a zeolite carrier.
The method for producing an oxygen scavenger according to claim 1, wherein the method is carried out by contacting at a flow rate of at least ml / min. 4. Immediately before performing stabilization treatment with carbon dioxide gas,
2. The method for producing an oxygen scavenger according to claim 1, wherein the zeolite carrier supporting the magnesium compound is subjected to degassing. 5. An oxygen scavenger produced by the production method according to claim 1. 6. The oxygen scavenger according to claim 5, further comprising an activation treatment with water after the stabilization treatment with carbon dioxide gas. 7. The method for using an oxygen scavenger according to claim 5, wherein the oxygen in the oxygen barrier container is deoxygenated in an atmosphere inside the container under a high humidity atmosphere of 60% RH or more.