JPS6041985B2 - oxygen absorber - Google Patents

Description

[Detailed description of the invention] The present invention relates to an oxygen absorbent.

More specifically, the present invention relates to an oxygen absorbent containing ferrous acetate, sodium carbonate 107, a salt, and a filler. The oxygen absorbent according to the present invention is made to coexist in a sealed container with food or other materials that would rot, change in quality, or deteriorate due to contact or reaction with oxygen, and effectively absorb oxygen in the container. This may cause spoilage, deterioration, etc. of food, etc.
It has the effect of preventing deterioration.

Conventionally, as a means of preserving foods to prevent spoilage, deterioration, and deterioration, there have been three methods: (1) refrigeration, (2) inert gas replacement using inert gases such as carbon dioxide, ethylene, and nitrogen, and (3) preservation systems. There are methods such as the vacuum packing method in which food is vacuum packed, and there is also a method of adding food additives such as antioxidants and anti-corrosion agents to the food.

BACKGROUND OF THE INVENTION Recently, the use of food additives for food preservation has come to be strictly restricted and regulated from the viewpoint of adverse effects on animals, especially on the human body.

On the other hand, among the above preservation methods, the refrigeration method requires very large refrigeration equipment and complicated operations, and is also economically expensive. In addition, the inert gas substitution method and the vacuum packing method not only require complicated operations, but also have insufficient storage stability. Therefore, if a simple and inexpensive method for preserving food could be provided, its industrial value would be extremely large.

When preserving food, things that cause spoilage, deterioration, and deterioration can include mold, bacteria, insects, and double bonds in the food, but most of these can survive in the presence of oxygen.
It causes putrefaction, alteration, and deterioration due to propagation or oxidation reactions. Therefore, if oxygen can be selectively removed from airtight containers during food storage, mold, bacteria,
It is possible to prevent the survival and reproduction of insects and the like, and it is also possible to suppress oxidation reactions of double bonds in foods.

Conventionally, there is a method of preserving food by removing oxygen in the packaging container, for example, a method using calcium hydroxide or sodium bicarbonate, activated carbon, and water with hydroxide sulfite as the main agent (Japanese Patent Publication No. 47-197 (2) method using sulfite and activated carbon (see Japanese Patent Publication No. 51-12471). However, the former method has the drawback that the reaction occurs rapidly, making it difficult to handle and requiring water. Furthermore, the latter method has the disadvantage that generation of sulfur dioxide gas cannot be avoided. The present inventors have overcome the drawbacks of the conventionally proposed methods and selectively removes oxygen from the packaging of foods, medicines, equipment, etc., and removes mold and bacteria from the contents of the packaging.
The present invention was achieved as a result of research into an oxygen absorbent that prevents the survival and reproduction of insects, etc., and suppresses putrefaction, deterioration, or deterioration caused by oxidation reactions, and can be applied to the safe and convenient preservation of foods.

According to the present invention, an oxygen absorbent containing ferrous acetate, sodium carbonate decahydrate, and a filler is provided.

The oxygen absorbent according to the present invention does not involve a rapid exothermic reaction, smoothly absorbs oxygen, and does not generate dangerous gases such as sulfur dioxide gas.

Furthermore, there is no need to add free water and it is extremely clean. Moreover, the oxygen absorbent of the present invention is almost white with a pale blue-green tinge, and when it absorbs oxygen, it turns brown, so it is possible to observe whether oxygen absorption has taken place or not by the change in color. This fact can also be used to determine the freshness of the packaged contents. On the other hand, the oxygen absorbent of the present invention can also be used as a detection substance that detects the presence of oxygen in a certain atmosphere by utilizing the color change. The ferrous acetate in the oxygen absorbent of the present invention is an anhydrous salt, and is a white compound with a very slight bluish-green color that is solid at room temperature. If it is left in the air for a long time, it will give off a slight odor of acetic acid, but it cannot be used as an oxygen absorbent because it absorbs almost no oxygen in an oxygen atmosphere (for example, in the air). However, when ferrous acetate is combined with sodium carbonate 10* salt and a filler, it becomes capable of absorbing oxygen, and its color changes from white with a pale bluish-green tinge to brown due to the absorption of oxygen.

Moreover, in the oxygen absorbent of the present invention, no acetic acid odor is observed either before or after oxygen absorption, and as the oxygen absorption progresses, the solid becomes finely divided and oxygen absorption is carried out smoothly. The ferrous acetate used in the present invention may be commercially available or may be synthesized by various methods.

For example, one method of reacting iron carbonyl with acetic acid [Zh
．． Org. ．． Khim7 (1971) 11, 2316-
19], ferrous acetate can be obtained by reacting reduced iron with acetic acid under reduced pressure at room temperature, or by heating ring element iron with acetic acid under normal pressure or reduced pressure, but other methods can also be used. The products thus obtained can also be used in exactly the same manner. On the other hand, the sodium carbonate monotonic salt used in the present invention may be obtained by any method, for example, by the ammonia soda method (Solvay method), by the carbonation method of caustic soda, that is, by the liquid It may be manufactured by a method such as blowing carbon dioxide gas into caustic soda.

Sodium carbonate is used as the monohydrate salt of the present invention, but even if it is a heptahydrate or monohydrate from which some water has been removed, it cannot be used, and these are more expensive than decahydrate. Must be used in large quantities. It is also possible to control the oxygen absorption rate by using these heptahydrate salts or monohydrate salts. In the oxygen absorbent of the present invention, the ratio of ferrous acetate and monotonic sodium carbonate can be freely changed depending on the desired characteristics of the oxygen absorbent.

In other words, if you want to increase the oxygen absorption rate, acetic acid
It is sufficient to increase the amount of sodium carbonate 10* salt relative to iron, and conversely, if the oxygen absorption rate is to be decreased, the ratio of sodium carbonate 10* salt to ferrous acetate may be reduced. Usually, 1 part by weight of ferrous acetate per 1 part by weight of sodium carbonate
A sufficient oxygen-absorbing effect can be achieved by setting the salt content to 0.01 parts by weight or more, preferably 0.05 parts by weight or more, particularly preferably 0.1 parts by weight or more. On the other hand, if the mixing ratio of sodium carbonate salt becomes too large, the amount of oxygen absorbent per unit weight of oxygen absorbent decreases, so the upper limit is self-limited. Normally, the amount of sodium sulfate monochloride per 1 part by weight of ferrous acetate is suitably 100 parts by weight or less, preferably 5 parts by weight or less, particularly preferably 2 parts by weight or less. The filler in the present invention can disperse ferrous acetate and monosodium carbonate well, can appropriately control the oxygen absorption amount and oxygen absorption rate, and also improves the air permeability of the oxygen absorbent itself. It has the effect of causing

Such fillers are chemically inert themselves, such as ferrous acetate or sodium carbonate 10* salt, and are particularly good if they are insoluble or sparingly soluble in water.

Examples of such fillers include activated carbon, diatomaceous earth, zeolite, kaolin, activated clay, silicon carbide, silicon nitride, colloidal silica, graphite, magnesium oxide, α-
Inorganic fillers such as , β-, or γ-alumina, silica alumina, anhydrous silica, mica, glass powder, and iron oxide; organic fillers such as various phthalic acids, cellulose, and synthetic resin powder (eg, polyaramid powder). The filler is 0.001 part by weight or more, preferably 0.0 part by weight, based on 1 part by weight of ferrous acetate and sodium carbonate decahydrate.
It is advantageous to use more than 1 part by weight. The upper limit of the amount of filler to be used is limited by the fact that if too much is used, the amount of oxygen absorbed per unit of oxygen absorbent decreases and becomes economically undesirable, but in general, ferrous acetate and sodium sulfate 10-aqueous It is sufficient that the amount is 5 parts by weight or less, preferably 2 parts by weight or less, particularly preferably 1 part by weight or less, per 1 part by weight of the total salt. In the present invention, the oxygen absorbent may be in any form.

For example, if ferrous acetate, sodium carbonate decahydrate, and filler are each finely powdered and simply mixed together, a mortar, agate bowl, sieve machine, ball mill, gearcon powder, internal mixer, etc. Grind using
It can be used as a powder (such as a mixed product), or the mixed powder can be used in a tablet machine, an extrusion molding machine,
Formed into pellets, pieces, rods, etc. by roll forming machines, etc.
It may be molded into a block shape, sheet shape, or the like. At that time, binders and lubricants that are commonly used in powder molding can also be used. Examples of binders include starch, carboxymethylcellulose, high molecular weight polymers such as polyvinyl acetate, polyolefins, and polyvinyl alcohol, and examples of lubricants include various stearic acid derivatives. . The oxygen absorbent of the present invention can be used in powder form or as is after being molded as described above, or it can be placed in a bag made of breathable packaging material, such as cellophane, various synthetic gun resin films, paper, etc. It can also be used as

As long as it is breathable, the material and structure of the packaging material can be varied. The oxygen absorbent of the present invention can be used for purposes such as removing oxygen, reducing oxygen content, and detecting the presence of oxygen, and the amount used can be selected as appropriate depending on the purpose and use. In particular, it can be advantageously applied to holding various foods, medicines, metals, and precision equipment that deteriorates or changes in quality due to oxygen.

The present invention will be described in detail below with reference to Examples.

Example 1 10 y of ferrous acetate [Fe(ACO)2], 10 y of sodium carbonate salt and 1.0 y of magnesium oxide were sufficiently ground in an agate bowl in a nitrogen atmosphere.

When the powder was exposed to an oxygen atmosphere with an oxygen partial pressure of 1 atm at )2C)C, it was 25cc in 2 hours and 30cc in 11 hours.
Oxygen absorption of c was observed. This oxygen absorbent was white with a pale gray tinge at the time of preparation, but as it absorbed oxygen, it turned pale brown and finally dark brown.

Oxygen absorption continued even after 1 m. Comparative Example 1 Ferrous acetate [Fe (ACO) 21.0y was sufficiently ground in an agate pot under a nitrogen atmosphere and exposed to an oxygen atmosphere of 1 atm at 20°C. Even after 5 hours, there was no substantial oxygen absorption. I couldn't accept it.

Furthermore, ferrous acetate remained white, almost unchanged from when it was prepared. Examples 2 to 6 Oxygen absorption experiments were conducted in Example 1 using various fillers instead of magnesium oxide and under the same conditions as in Example 1, and the results shown in Table 1 were obtained.

As is clear from this table, it can be seen that the oxygen absorption rate changes by changing the type and amount of filler.

Claims (1)

[Claims] 1. An oxygen absorbent containing ferrous acetate, sodium carbonate decahydrate, and a filler.