JP3480474B2 - Oxygen scavenger - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deoxidizer having a deoxidizing ability even under a drying condition of 30% RH or less. More specifically, the present invention relates to an oxygen scavenger that can be applied to the preservation of dry foods and pharmaceuticals and the preservation of metal products for rust prevention.

[0002]

2. Description of the Related Art Recently, as a method of storing food in a hermetically sealed package, various methods using oxygen scavengers have been developed and attracted attention as one of the cheap and easy food storage methods. A large number of oxygen scavengers using various inorganic and organic base materials have been proposed so far. For example, metal powders such as iron, sulfites, bisulfites, and dithionite salts are used as inorganic base agents, L-ascorbic acid, ersorbic acid and salts thereof as organic base agents, and gluco-
Examples thereof include sugars such as glucose, reducing polyvalent phenols such as catechol and pyrogallol, and polyvalent alcohols such as ethylene glycol and glycerin.
However, these conventional oxygen scavengers have a problem that a practical oxygen scavenging ability cannot be obtained unless water or a substance that supplies water during use coexists. That is,
The conventional oxygen scavenger is prepared by mixing water or a substance that retains water when used, for example, a compound having water of crystallization, or by utilizing steam generated from the food to be preserved. For the first time, it was possible to obtain a practical deoxidizing ability. Therefore, it has not been possible to apply the conventional oxygen absorber to the rust-preserving preservation of dry foods, pharmaceuticals and metal products that need to be preserved under dry conditions and the presence of water or water.

Therefore, in order to solve the above problems of the conventional oxygen scavengers, the following proposals have been made as oxygen scavengers for a dry system which does not use any water or steam supply. (1) Improved conventional oxygen scavenger (2) Unsaturated fatty acid or fat or oil containing it is used as the main component (3) Activated metal supported is used as the main component

Regarding (1), for example, JP-A-63-6 is used.
2547, a polyvalent phenol such as conventional catechol
, L-ascorbic acid as the main agent, and a composition obtained by adding a mixture of a basic substance such as alkalis and polyvalent alcohol such as ethylene glycol, and a filler such as activated carbon to a mechanical part, a precision component. It is used as an oxygen scavenger for rust-preserving parts. However, it is essential to use alkalines, which are basic substances that are not preferable for safety, and the applicable humidity is 30
Since it is more than% RH, it is strict in safety, and 3
There is a problem that it cannot be used for storing dried foods, pharmaceuticals, etc., which need to be stored at a low humidity of 0% RH or less.

Regarding (2), for example, Japanese Patent Publication No. 62-6
0936 describes an oxygen scavenger for dry foods, which comprises an unsaturated fatty acid or an oil or fat containing an unsaturated fatty acid, a carrier and a transition metal catalyst. JP-A-63-198962 improved by adding a basic substance thereto. , JP-A-64-67252 and the like. However, the oxygen scavengers that use these unsaturated fatty acids or fats and oils containing them as the main agent have problems such as the odor of the main agent itself and the generation of septic offensive odor due to the oxidation of the main agent, and are sensitive to odors. It could not be applied to various foods and pharmaceuticals.

Regarding (3), for example, Chemist
ry and Industry, 4,363 (197)
0). Describes a chrome metal supported on silica activated with carbon monoxide as a desiccant having a deoxidizing ability. However, the oxygen scavenging ability of this desiccant is insufficient for use as a oxygen scavenger, and the chromium metal used has many problems in terms of safety, and it is not safe to store foods, pharmaceuticals, etc. It was not applicable.

Further, Japanese Patent Publication No. 3-71171 describes an oxygen scavenger having a dehumidifying function by activating a supported nickel metal and zeolite as a main component with hydrogen. This proposal is expected to be one of the leading oxygen absorbers for dry systems because it does not have the problem of generating odors and offensive odors, but it uses a basic substance as another component, and foods and pharmaceuticals with severe safety Could not be applied to save such. Furthermore, regarding metals other than nickel metal, there is a description in Japanese Patent Publication No. 3-71171 described above in which a composition consisting of iron metal supported on zeolite and a basic substance was similarly activated with hydrogen, but this was dried. It is noted that under the conditions, it does not have sufficient deoxidizing ability. Therefore, nothing was known about other metals.

[0008]

The object of the present invention is to solve the problems of the deoxidizing agent used in the conventional drying system, and it can be used even under the drying condition where the applied humidity is 30% RH or less. It is an object of the present invention to provide a highly safe and reusable oxygen scavenger for a dry system, which is free from the generation of oxygen and does not require the use of water or a basic substance. Another object of the present invention is to provide an oxygen scavenger that can be applied to foods, pharmaceuticals, and the like that need to be dried and stored, and that can be applied to, for example, rust-preserving preservation of metal products.

[0009]

Means for Solving the Problems The present inventors have found that an activated metal supported on a carrier is used as a highly safe oxygen scavenger consisting only of a main component and water without the need for a catalyst such as a basic substance to exhibit its function. Developed an oxygen scavenger based on V, Mn, F
An oxygen scavenger containing e, Co, Ni, Mo or W as a main agent was proposed in Japanese Patent Application No. 6-175347, and an oxygen scavenger containing a Cu main agent was previously proposed in Japanese Patent Application No. 6-175348. Furthermore, regarding the oxygen scavenger of various activated metal base agents supported on the above-mentioned carrier, the oxygen scavenging ability under a dry condition of 30% RH or less was reexamined without using water. We have found that activated metals such as iron, cobalt and copper have deoxidizing ability under dry conditions. Hereinafter, the drying conditions in the present invention all refer to humidity conditions of 30% RH or less.

The oxygen scavenger of the present invention is characterized in that it comprises only activated metal supported on a carrier. Specifically, the activating metal supported on the carrier is an oxygen scavenger that is at least one metal selected from the transition metals manganese, iron, cobalt, and copper. The oxygen scavenger of the present invention is also an oxygen scavenger that can be reused by a reactivation treatment.

In the present invention, the above metal to be activated must be supported on a carrier. In other words, it is almost impossible to obtain the deoxidizing ability under the drying condition with the above-mentioned metal and carrier which are simply added, mixed and activated. In addition, in the present invention, activation means that a metal or its metal compound is reduced by heating or decomposed by heat to impart deoxidizing ability to the metal of the main component.

The metal used in the present invention is at least one metal selected from the transition metals manganese, iron, cobalt and copper, and two or more metals can be used in combination. In the present invention, the metal is an inorganic salt thereof,
Alternatively, the organic salt is supported on a carrier and activated to be used.
As the inorganic salt, sulfates, nitrates, hydrochlorides, carbonates and the like of the above metals are used, and as the organic salts, formates, acetates and oxalates of the above metals are used.

The carrier used in the present invention is not particularly limited, but for example, activated carbon, silica, diatomaceous earth,
Inorganic carriers such as clay, zeolite, celite and acid clay can be mentioned. The inorganic salt or organic salt of the metal is supported on these carriers by a known method such as an impregnation method or a coprecipitation method.

The amount of supported metal is 5 as reduced metal.
˜90 wt% is used, and especially 30 to 80 wt% is preferably used.

The inorganic salt or organic salt of the metal supported as described above may be activated in a granular or powder form before being activated, or may be activated by pressure molding, extrusion molding or the like. It may be activated after being formed into an appropriate shape by a usual forming method.

Examples of the method for activating the supported inorganic salt of the above metal include thermal chemical reduction with formalin and formic acid, and thermal catalytic reduction with a reducing gas such as carbon monoxide and hydrogen. Particularly, catalytic reduction by heating is preferable. As a method of activating the supported organic salt of the metal, it can be activated simply by decomposing it by heating in an inert gas, but it may be activated by heating in a reducing gas such as carbon monoxide or hydrogen.

The activation conditions used in the present invention are different depending on the supported inorganic salt or organic salt, but usually 100
~ 700 ° C for 10 minutes to 10 hours, especially 200
It is preferably used at ~ 600 ° C for 30 minutes to 6 hours.

Since the activated oxygen scavenger obtained in the present invention is easily oxidized in the air, it is usually stored in a small bag whose air permeability is controlled in an anaerobic atmosphere such as nitrogen. Then, the oxygen scavenger contained in this small bag is put in a non-breathable, non-moisture permeable closed package together with dried foods, pharmaceuticals, metal products, etc., and used for storage of these articles.

The non-breathable, non-moisture-permeable, hermetically-sealed packaging material used herein is preferably a packaging material having a material excellent in humidity barrier property as much as possible. Therefore, for example, aluminum vapor-deposited polyethylene (PE), which is a packaging material containing an inorganic material rather than a packaging material made of only an organic material, a laminated film of aluminum foil and PE, and the like are preferably used.

The oxygen scavenger of the present invention is an oxygen scavenger that can be easily reactivated and reused. As a method for reactivating the used oxygen scavenger, after removing the oxygen scavenger from the stored sachet, it can be activated by the activation method used first as it is, especially carbon monoxide, hydrogen etc. A method of heating catalytic reduction in a reducing gas is preferably used.

[0021]

EXAMPLES Examples will be described below. Example 1 57.4 g of manganese nitrate hexahydrate was added to 200 ° C. water at 200 ° C.
20 ml of diatomaceous earth was added to this, and the mixture was stirred. Next, an aqueous solution prepared by dissolving 25.44 g of anhydrous sodium carbonate in 120 ml of water was added dropwise, and then stirred for 2 hours. After the completion of stirring, the insoluble matter was collected by filtration, washed with water until the filtrate became neutral, and dried at 110 ° C. About 0.5g of this dried product
Was pressure-molded under the condition of 300 kg / m ² for 3 minutes to prepare a disk-shaped molded body having a diameter of 12 mm. Two of these molded bodies were placed in a small quartz dish with an aluminum net lid, preheated in a nitrogen stream at 200 ° C for 30 minutes, and then in a hydrogen stream 45
It was reduced at 0 ° C. for 3 hours. After the reduction is completed, nitrogen is circulated to cool it to room temperature, and a quartz small dish containing 0.75 g of the reduced product is laminated with perforated polyethylene in a nitrogen-filled glove box. Then, the pouch was placed in an aluminum foil / PE package and deaerated. This degassed aluminum foil / PE package is taken out of the glove box, and 250 ml of air with a humidity of 40% RH is added to it.
It was injected and stored at 25 ° C., and the amount of oxygen absorbed in the bag and the humidity were analyzed over time. The results are shown in Table 1.

Example 2 55.6 g of ferrous sulfate heptahydrate was added to 550 m of water at 60 ° C.
20 g of zeolite was dissolved in 1 of water and stirred. Next, 25.44 g of anhydrous sodium carbonate was added to 100 parts of water.
An aqueous solution dissolved in ml was added dropwise, and then the mixture was stirred for 1 hour and 30 minutes. After stirring, the insoluble matter was collected by filtration, washed with water until the filtrate became neutral, and dried at 110 ° C. About 0.5 g of this dried product was molded in exactly the same manner as in Example 1, two molded products were placed in a small quartz dish with a lid of an aluminum net, and preheated at 200 ° C. for 30 minutes in a nitrogen stream. Then, reduction was carried out in a hydrogen stream at 500 ° C. for 3 hours. After the reduction is completed, nitrogen is circulated to cool it to room temperature, and a quartz small dish containing 0.80 g of the reduced product is laminated with perforated polyethylene in a nitrogen-filled glove box. Then, the pouch was placed in an aluminum foil / PE package and deaerated. This degassed aluminum foil / PE package is
The bag was taken out of the box and 250 ml of air having a humidity of 40% RH was injected into the box, which was stored at 25 ° C. and the amount of oxygen absorbed in the bag and the humidity were analyzed over time. The results are shown in Table 1.

Example 3 58.2 g of cobalt nitrate hexahydrate was added to 150 ° C. of water 150
20 g of acid clay was added thereto and stirred.
Next, 31.8 g of anhydrous sodium carbonate was added to 200 ml of water.
The aqueous solution dissolved in was added dropwise and then stirred for 2 hours.
After the completion of stirring, the insoluble matter was collected by filtration, washed with water until the filtrate became neutral, and dried at 110 ° C. After the reduction is completed, nitrogen is circulated to cool it to room temperature, and a small pouch made of quartz containing 0.77 g of the reduced product is laminated with perforated polyethylene in a nitrogen-filled glove box. Then, the pouch was placed in an aluminum foil / PE package and deaerated. This degassed aluminum foil / PE package is
The bag was taken out of the box and 250 ml of air having a humidity of 40% RH was injected into the box, which was stored at 25 ° C. and the amount of oxygen absorbed in the bag and the humidity were analyzed over time. The results are shown in Table 1.

Example 4 48.32 g of cupric nitrate trihydrate was added to 200 ° C. water at 40 ° C.
It was dissolved in ml, and 20 g of zeolite was added thereto and stirred. Next, 16.0 g of sodium hydroxide was added to 200 m of water.
The aqueous solution dissolved in 1 was added dropwise, and then stirred for 1 hour and 30 minutes. After the completion of stirring, the insoluble matter was collected by filtration, washed with water until the filtrate became neutral, and dried at 110 ° C. About 0.5 g of this dried product was molded in exactly the same manner as in Example 1, two molded products were placed in a small quartz dish with a lid of an aluminum net, and preheated at 200 ° C. for 30 minutes in a nitrogen stream. Then, hydrogen stream was reduced at 300 ° C. for 3 hours. After the reduction is completed, nitrogen is circulated to cool it to room temperature, and a quartz quartz small box containing 0.87 g of the reduced product is placed in a nitrogen-filled glove box.
Pack the paper in a paper pouch laminated with perforated polyethylene,
Furthermore, this small bag was put in an aluminum foil / PE package and deaerated. This degassed aluminum foil / PE package is taken out of the glove box, and 25% of air with a humidity of 40% RH is added to it.
0 ml was injected, this was stored at 25 ° C., and the amount of oxygen absorbed in the bag and the humidity were analyzed over time. The results are shown in Table 1.

Example 5 19.65 g of ammonium metavanadate was added to 200 ml of water at about 50 ° C., and 21.18 g of oxalic acid was added thereto.
After adding an aqueous solution dissolved in 0 ml of water, 20 g of zeolite was added thereto and stirred for 3 hours. After the completion of stirring, water was distilled off under reduced pressure and dried at 110 ° C. This dried product is about 0.
5 g was molded in exactly the same manner as in Example 1, and two molded products were placed in a small quartz dish with an aluminum net lid, preheated in a nitrogen stream at 200 ° C. for 30 minutes, and then a hydrogen stream 700
Reduced at 4 ° C for 4 hours. After the reduction is completed, nitrogen is circulated to cool it to room temperature, and a quartz small dish containing 0.81 g of the reduced product is laminated with perforated polyethylene in a nitrogen-filled glove box. Then, the pouch was placed in an aluminum foil / PE package and deaerated. This degassed aluminum foil / PE package is taken out of the glove box, 250 ml of air with a humidity of 40% RH is injected into it, and this is stored at 25 ° C. to absorb oxygen in the bag over time. The amount and humidity were analyzed. The results are shown in Table 1.

Example 6 19.48 g of ammonium molybdate tetrahydrate was added as 6 parts.
Dissolve in 200 ml of water at 0 ° C and add 20 g of zeolite.
Was added, and the mixture was stirred as it was for 3 hours. After the completion of stirring, water was distilled off under reduced pressure and dried at 110 ° C. About 0.5g of this dried product
Example 1 was molded exactly as in Example 1, and the two molded bodies were placed in a small Petri dish with a lid of an aluminum net, preheated in a nitrogen stream at 200 ° C for 30 minutes, and then a hydrogen stream at 650 ° C.
Reduced for 4 hours. After the reduction is completed, nitrogen is circulated to cool to room temperature, and a small pouch made of quartz containing 0.76 g of the reduced product is laminated with perforated polyethylene in a nitrogen-filled glove box. Then, the pouch was placed in an aluminum foil / PE package and deaerated. This degassed aluminum foil / PE package is taken out of the glove box, 250 ml of air with a humidity of 40% RH is injected into it, and this is stored at 25 ° C. to absorb oxygen in the bag over time. The amount and humidity were analyzed. The results are shown in Table 1.

Example 7 12.17 g of ammonium tungstate pentahydrate was dissolved in 200 ml of water at 80 ° C. and zeolite 20 was added thereto.
g, and stirred for 3 hours as it was. After the completion of stirring, water was distilled off under reduced pressure and dried at 110 ° C. About 0.5g of this dried product
Example 1 was molded exactly as in Example 1, and the two molded bodies were placed in a small Petri dish with a lid of an aluminum net, preheated in a nitrogen stream at 200 ° C for 30 minutes, and then a hydrogen stream at 650 ° C.
Reduced for 4 hours. After the reduction is completed, nitrogen is circulated to cool it to room temperature, and a small pouch made of quartz containing 0.77 g of the reduced product is laminated with perforated polyethylene in a nitrogen-filled glove box. Then, the pouch was placed in an aluminum foil / PE package and deaerated. This degassed aluminum foil / PE package is taken out of the glove box, 250 ml of air with a humidity of 40% RH is injected into it, and this is stored at 25 ° C. to absorb oxygen in the bag over time. The amount and humidity were analyzed. The results are shown in Table 1.

Reference Example 1 Nickel nitrate hexahydrate 45.0 g was added to 60 g of water 150.
It was dissolved in ml, and 20 g of zeolite was added thereto and stirred. Next, 20.0 g of anhydrous sodium carbonate was added to water 10
An aqueous solution dissolved in 0 ml was added dropwise and then stirred for 2 hours. After the completion of stirring, the insoluble matter was collected by filtration, washed with water until the filtrate became neutral, and dried at 110 ° C. About 0.5 g of this dried product was molded in exactly the same way as in Example 1, and a molded body 2
Put the pieces in a small quartz dish with an aluminum net lid,
After preheating at 200 ° C for 30 minutes in a nitrogen stream, hydrogen stream 4
It was reduced at 50 ° C. for 3 hours. After the reduction is completed, nitrogen is circulated and cooled to room temperature, and a small pouch made of quartz containing 0.67 g of the reduced product is laminated with perforated polyethylene in a nitrogen-filled glove box. Then, the pouch was placed in an aluminum foil / PE package and deaerated.
The degassed aluminum foil / PE package is taken out of the glove box, and air with a humidity of 40% RH is set to 250 m.
Then, the amount of oxygen absorbed in the bag and the humidity were analyzed over time. The results are shown in Table 1.

[0029]

[Table 1]

As is clear from Table 1, there are manganese, iron, cobalt, and copper in addition to nickel as the activated metals having deoxidizing ability even under dry conditions. Among them, iron, cobalt, and particularly cobalt have deoxidizing ability. It can be seen that is large and excellent in practicality. Further, it is found that the oxygen scavenger using these supported activated metals has an excellent dehumidifying ability regardless of the supported metal species. Furthermore, vanadium, molybdenum, and tungsten, which have a deoxidizing ability under the condition of adding water, have almost no deoxidizing ability under a drying condition. It can be seen that they are significantly different.

Comparative Example 1 8.90 g of manganese dioxide and 10 g of diatomaceous earth were uniformly mixed, and about 0.5 g of this mixture was molded under exactly the same conditions as in Example 1, and two molded bodies were covered with an aluminum lid. The sample was placed in a small quartz dish and subjected to the same reduction and preparation as in Example 1, and this was stored at 25 ° C., and the amount of oxygen absorbed in the bag and the humidity were analyzed over time. The results are shown in Table 2.

Comparative Example 2 An iron compound was prepared in the same manner as in Example 2 except that 20 g of the zeolite carrier was not used. 2 g of this iron compound and 2.5 g of Zeophyl were uniformly mixed, and about 0.5 g of this mixture was molded under exactly the same conditions as in Example 1, and two molded bodies were made of quartz with a small aluminum cap. Then, reduction and charging were carried out in exactly the same manner as in Example 2, and this was stored at 25 ° C. and the amount of oxygen absorbed in the bag and the humidity were analyzed over time. The results are shown in Table 2.

Comparative Example 3 A cobalt compound was prepared in the same manner as in Example 3, except that 20 g of the acidic clay carrier was not used. 11.85 g of this cobalt compound and 10 g of zeolite were uniformly mixed, and about 0.5 g of this mixture was molded under exactly the same conditions as in Example 1, and two of these molded bodies were made of quartz with a small aluminum cap. The bag was placed in a bag, reduced and charged exactly as in Example 3, stored at 25 ° C., and the amount of oxygen absorbed in the bag and the humidity were analyzed over time. The results are shown in Table 2.

Comparative Example 4 8.0 g of cupric oxide and 10 g of zeolite were uniformly mixed, and about 0.5 g of this mixture was molded under exactly the same conditions as in Example 1, and two molded bodies were covered with an aluminum lid. The sample was placed in a small quartz dish attached thereto, subjected to the same reduction and preparation as in Example 4, stored at 25 ° C., and subjected to oxygen absorption amount and humidity analysis with time. The results are shown in Table 2.

Comparative Example 5 9.83 g of ammonium metavanadate and zeolite 1
0 g was mixed uniformly and about 0.5 g of this mixture was added to Example 1
Molded under exactly the same conditions as in the above, placed two of these molded bodies in a small quartz dish with an aluminum lid, reduced and charged exactly as in Example 5, and stored this at 25 ° C. The amount of oxygen absorbed in the bag and the humidity were analyzed. The results are shown in Table 2.

Comparative Example 6 6.44 g of molybdenum trioxide and 10 g of Zeophyl were uniformly mixed, and about 0.5 g of this mixture was molded under exactly the same conditions as in Example 1, and two molded bodies were covered with an aluminum lid. The mixture was placed in a small quartz dish and reduced and charged in exactly the same manner as in Example 6, and this was stored at 25 ° C. and the amount of oxygen absorbed in the bag and the humidity were analyzed over time. The results are shown in Table 2.

Comparative Example 7 Tungsten trioxide (5.41 g) and zeophyl (10 g) were uniformly mixed, and about 0.5 g of this mixture was molded under exactly the same conditions as in Example 1, and two molded bodies were covered with an aluminum lid. Placed in a small quartz dish and reduced exactly as in Example 7.
After preparation, the bag was stored at 25 ° C., and the amount of oxygen absorbed in the bag and the humidity were analyzed over time. The results are shown in Table 2.

Reference Example 2 The same reaction as in Reference Example 1 was carried out without using 20 g of the zeolite carrier to prepare a nickel compound. 2.5 g of this nickel compound and 2.1 g of Zeophyl were uniformly mixed, and about 0.5 g of this mixture was molded under exactly the same conditions as in Example 1. Two molded bodies were made of quartz with an aluminum lid. The mixture was placed in a dish, reduced and charged exactly as in Reference Example 1, stored at 25 ° C., and the amount of oxygen absorbed in the bag and the humidity were analyzed over time. The results are shown in Table 2.

[0039]

[Table 2]

As is clear from the comparison between Table 1 and Table 2, the deoxidizing ability of the supported activated metal under the dry condition is significantly higher than that of the unsupported activated metal.

Example 8 In Example 3, instead of the carrier acid clay, diatomaceous earth, zeolite, silica, alumina, titania, pearlite,
Each supported product was prepared in exactly the same manner as in Example 3 except that acid clay, silica titania, and activated carbon were used. About 0.5 g of each of these preparations was molded under exactly the same conditions as in Example 1, and the two molded products were placed in a small quartz dish with an aluminum lid. It was reduced and charged, stored at 25 ° C., and the oxygen absorption in the bag and the humidity were analyzed over time. The results are shown in Table 3.

[0042]

[Table 3]

As is apparent from Table 3, the carrier effect on the deoxidizing ability is large, and acid clay, zeolite, diatomaceous earth, titania and activated carbon are preferably used. On the other hand, regarding the dehumidifying ability, it is understood that there is not much difference depending on the carrier, and all have the ability to bring the dried state to 10% RH or less within almost one hour.

Example 9 14.55 g of cobalt nitrate hexahydrate was added to water of about 70 ° C. in 5 parts of water.
The solution was dissolved in 0 ml, and the carrier of acidic clay was added thereto in an amount such that the Co loading rate would be 5, 20, 37, 60, 80, 90 wt%, and the mixture was stirred. Next, an aqueous solution prepared by dissolving 10.6 g of anhydrous sodium carbonate in 50 ml of water was added dropwise.
After completion of dropping, the mixture was stirred for 2 hours as it was. After stirring, the insoluble matter was filtered off, washed with water until the filtrate became neutral, and dried at 110 ° C. About 0.5 g of each of these preparations was molded under exactly the same conditions as in Example 1, and the two molded products were placed in a small quartz dish with an aluminum lid. It was reduced and charged, stored at 25 ° C., and the oxygen absorption in the bag and the humidity were analyzed over time. The results are shown in Table 4.

[0045]

[Table 4]

As is clear from Table 4, the loading rate of the activated metal is 5 to 90% by weight, among which 37 to 8 are used.
It can be seen that 0 wt% is preferably used.

Example 10 After carrying out the experiment in Example 2 until the oxygen concentration after charging did not change, the supported product was taken out from the storage paper pouch into the air. The loaded product taken out began to generate heat 30 seconds after being taken out into the air, and cooled to room temperature after several minutes. Next, the above-mentioned used supported product was reduced and charged again exactly as in the first time, and the experiment was continued until no change in oxygen concentration was observed, and then the supported product was taken out into the air as in the first time. Table 5 shows the oxygen absorption amount and humidity change in the bag after this operation was repeated 5 times.

[0048]

[Table 5]

As is clear from Table 5, the oxygen scavenger of the present invention is
It can be seen that the reduction facilitates reactivation and allows reuse.

Example 11 About 1.0 g of the dried product prepared in Example 2 was molded in exactly the same manner as in Example 1, and 5 molded products were placed in a small quartz dish with an aluminum net lid. , Exactly the same as in Example 2. After the reduction is completed, nitrogen is circulated to cool it to room temperature,
In a glove box filled with nitrogen, a small quartz dish containing 4.0 g of the reduced product was packed in a paper pouch laminated with perforated polyethylene. This paper pouch is taken out of the glove box, and this paper pouch and 10 pieces of grilled plate laver with a size of 10 cm × 10 cm are put in an aluminum foil / PE package to be deaerated, and then the humidity is 80% RH. 250m of air
It was charged into the bag and stored at 25 ° C., and the oxygen concentration and humidity in the bag were analyzed over time. Furthermore, one week after the start of storage,
One month later, the container was opened, and a sensory test for offensive odor and a visual inspection of the preserved product were conducted. The results are shown in Table 6.

Comparative Examples 8 to 10 For comparison with Example 11, iron powder 0.2 g, water 0.2 g, sodium chloride 0.5 g, activated carbon 0.2 g were used instead of the oxygen scavenger used in Example 11. Was mixed, and the mixture was mixed with the iron-based oxygen scavenger housed in the same paper pouch as in Example 11,
It carried out and evaluated exactly as in Example 11 (Comparative Example 8). Further, instead of the oxygen scavenger used in Example 11, 2 g of oleic acid and 0.2 g of iron oleate were uniformly mixed, and then 0.2 g of calcium oxide was added and well mixed,
The granular composition prepared by crushing the solid substance left at room temperature for 30 minutes in a mortar was evaluated in exactly the same manner as in Example 11 using the unsaturated fatty oxygen scavenger stored in the same paper pouch as in Example 11. (Comparative example 9). Furthermore, the same evaluation as in Example 11 was performed without using an oxygen absorber (Comparative Example 1).
0). The results are shown in Table 6.

As is clear from Table 6, by using the oxygen scavenger of the present invention, the dried state can be maintained and the dried food can be satisfactorily preserved without any odor or offensive odor.

[0053]

[Table 6]

Example 12 Reduced product obtained by molding and reducing in exactly the same manner as in Example 11.
In a glove box filled with nitrogen, 1 g was packed in a paper pouch laminated with perforated polyethylene while being placed in a container of a quartz dish with an aluminum net lid. This paper pouch was taken out of the glove box, and this paper pouch and 50 g of a commercially available dried Chinese herbal medicine Genshosho were further dried overnight at 70 ° C., which was then placed in an aluminum foil / PE package and deaerated, 250 ml of air having a humidity of 80% RH was charged into this, and this was stored at 35 ° C. to store the oxygen concentration in the bag over time.
Humidity analysis was performed. Further, two weeks after the start of storage and one month later, the package was opened, and a sensory test for offensive odor and a visual inspection of the stored product were conducted. The results are shown in Table 7.

Comparative Examples 11 to 13 For comparison with Example 12, the iron-based oxygen scavenger of Comparative Example 8 was used instead of the oxygen scavenger used in Example 12.
Evaluation was carried out exactly as in 2 (Comparative Example 11). Also,
The unsaturated fatty oxygen scavenger of Comparative Example 9 was used in place of the oxygen scavenger used in Example 12, and the same evaluation as in Example 12 was performed (Comparative Example 12). Furthermore, the same evaluation as in Example 12 was carried out without using an oxygen absorber (Comparative Example 1).
3). The results are shown in Table 7.

[0056]

[Table 7]

As is clear from Table 7, the oxygen scavenger of the present invention can be preferably used for pharmaceuticals requiring dry storage.

Example 13 About 1.0 g of the dried product prepared in Example 3 was molded in exactly the same manner as in Example 1, and the two molded products were placed in a small quartz dish with an aluminum net lid. The reduction was performed in exactly the same manner as in Example 3. After the reduction is completed, nitrogen is circulated to cool it to room temperature,
A small quartz dish containing 1.7 g of the reduced product was packed in a nitrogen-filled glove box in a paper pouch laminated with perforated polyethylene. This paper pouch was taken out of the glove box, and the paper pouch and mechanically polished copper-plated copper pieces (10 mm x 60 mm x 0.3 mm) were attached to aluminum foil /
After degassing by putting it in a PE package, add 80% RH to it.
250 ml of the above air was charged and stored at 35 ° C., and the oxygen concentration and humidity in the bag were analyzed over time. Further, after 1 week, 2 weeks, 3 weeks, and 1 month after the start of storage, the container was opened, and a sensory test for offensive odor and a state of rust generation in the stored product were examined. The results are shown in Table 8.

Comparative Examples 14 to 16 For comparison with Example 13, the iron-based oxygen scavenger of Comparative Example 8 was used instead of the oxygen scavenger used in Example 13.
Evaluation was carried out in the same manner as 3 (Comparative Example 14). Also,
The unsaturated fatty oxygen scavenger of Comparative Example 9 was used instead of the oxygen scavenger used in Example 13, and the evaluation was performed in exactly the same manner as Example 13 (Comparative Example 15). Furthermore, the same evaluation as in Example 13 was carried out without using an oxygen absorber (Comparative Example 1).
6). The results are shown in Table 8.

As is clear from Table 8, the oxygen scavenger of the present invention does not generate any offensive odor, maintains a dry state, and can be suitably used for rust-preserving preservation of metal products which do not like humidity.

[0061]

[Table 8]

[0062]

EFFECTS OF THE INVENTION By using the oxygen scavenger of the present invention, oxygen can be efficiently deoxidized even under a drying condition of 30% RH or less, and also has a dehumidifying ability, and no odor or offensive odor is generated. Moreover, since the oxygen scavenger of the present invention does not require water or a basic substance at all, it can be used for preservation of dried foods and pharmaceuticals to which conventional oxygen scavengers cannot be applied, and preservation of metal rust. It became so. Furthermore, the oxygen scavenger of the present invention does not need to be discarded even if it is deactivated by using, and the metal supported on the main component can be easily reactivated and reused,
It is an oxygen scavenger that greatly contributes to the effective use of resources.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-63-214351 (JP, A) JP-A-4-244228 (JP, A) JP-A-8-38885 (JP, A) JP-A-8- 38884 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B01J 20/02 A23L 3/3436

Claims (3)

(57) [Claims] 1. Deoxidization comprising an activated metal obtained by carrying out thermal reduction or thermal decomposition of an inorganic salt or organic salt of at least one transition metal selected from Mn, Fe, Co and Cu supported on an inorganic carrier. Agent. 2. The oxygen scavenger according to claim 1, which is for a drying condition of 30% RH or less. 3. An oxygen scavenger which can be reused by a reactivation treatment by heating catalytic reduction.
The described oxygen scavenger.