Deoxidizer composition, method for producing same, and deoxidizer package

Abstract

A deoxidizer composition containing iron powder, a halide of an alkaline earth metal, water, an alkaline substance, a water-retaining carrier, and one or more water-soluble solvents selected from the group consisting of a 1-3-membered alcohol having a molecular weight of 100 or less (excluding a polyether polyol) and a polyether having a number average molecular weight of 900 or less, the content of the halide of the alkaline earth metal is from 30 parts by mass to 80 parts by mass (inclusive) with respect to 100 parts by mass of the water content, and the content of the water-soluble solvent is from 2 parts by mass to 80 parts by mass (inclusive) with respect to 100 parts by mass of the water content.

Description

Technical Field

[0001] This invention relates to deoxidizer compositions, methods for manufacturing the same, and deoxidizer packaging. Background Technology

[0002] For a long time, deoxidizers utilizing the oxidation reaction of iron powder (hereinafter referred to as "iron-based deoxidizers") have been proposed. Commercially available deoxidizers (such as "AGELESS" manufactured by Mitsubishi Gas Chemical Co., Ltd.) can remove oxygen from the container by sealing it together with food, medicine and other items in an airtight container, and have been widely used to maintain the quality and freshness of the aforementioned items.

[0003] Iron-based deoxidizers include "moisture-dependent" deoxidizers that utilize the moisture evaporated from the stored material to initiate oxygen absorption, and "self-reactive" deoxidizers that pre-contain the moisture required for the oxygen absorption reaction of iron in the deoxidizer composition.

[0004] In "self-reactive" deoxidizers, by including water-supplying agents such as inorganic fillers impregnated with water in the deoxidizer composition, the water required for the oxygen absorption reaction of iron can be replenished from the water-supplying agent into the iron.

[0005] However, when storing or transporting "self-reactive" deoxidizers, there is a problem that the iron powder in the deoxidizer reacts with water to produce hydrogen.

[0006] Normally, deoxidizers are stored in gas-barrier bags in a way that prevents them from reacting with atmospheric oxygen until they are used. However, if hydrogen is generated under such storage conditions, it can sometimes cause the gas-barrier bags to expand and deform, resulting in poor appearance, or the gas-barrier bags to become loose and degassing is inadequate.

[0007] As a method to solve the problem of hydrogen generation, there is a known method that involves adding an alkaline substance such as calcium hydroxide to a deoxidizer composition to keep the water film on the surface of the iron powder, which is the reaction site of the deoxidation reaction, alkaline and thus suppressing hydrogen generation (Patent Document 1).

[0008] Existing technical documents

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Publication No. 2013-146668 Summary of the Invention

[0011] The problem the invention aims to solve

[0012] However, in deoxidizer compositions exhibiting moderate moisture activity, metal salts such as metal halides are used extensively. Consequently, the surface of the iron powder becomes susceptible to corrosion by these metal salts, and the aforementioned hydrogen generation problem becomes more pronounced.

[0013] Furthermore, if a large amount of metal salt is added along with an alkaline substance, the metal salt reacts with the alkaline substance, and reactants are precipitated. As a result, it is difficult to maintain the water film on the surface of the iron powder in an alkaline state, thus failing to inhibit hydrogen production. In addition, it is also difficult to maintain moderate water activity.

[0014] Therefore, there is a need for deoxidizer compositions that can maintain moderate moisture activity, suppress hydrogen production, and exhibit excellent oxygen absorption properties.

[0015] Therefore, the object of the present invention is to provide a deoxidizer composition that maintains moderate moisture activity while exhibiting excellent oxygen absorption and low hydrogen production, a method for manufacturing the same, and a deoxidizer packaging.

[0016] Solution for solving the problem

[0017] That is, the main structure of the present invention is as follows.

[0018] [1] A deoxidizing agent composition comprising iron powder, an alkaline earth metal halide, water, an alkaline substance, a water-retaining carrier, and one or more water-soluble solvents selected from the group consisting of 1 to 3 alcohols with a molecular weight of less than 100 (excluding polyether polyols) and polyethers with a number average molecular weight of less than 900.

[0019] The content of the aforementioned alkaline earth metal halides relative to the aforementioned water content is 30 parts by mass or more and 80 parts by mass or less per 100 parts by mass.

[0020] The content of the aforementioned water-soluble solvent is more than 2 parts by mass and less than 80 parts by mass relative to the content of the aforementioned water in 100 parts by mass.

[0021] [2] According to the deoxidizer composition described in [1] above, wherein the aforementioned water-soluble solvent is one or more selected from the group consisting of methanol, ethanol, propanol, propylene glycol, glycerol, butanol, butanediol, polyethylene glycol with a number average molecular weight of 900 or less, and polypropylene glycol with a number average molecular weight of 900 or less.

[0022] [3] According to the deoxidizer composition described in [1] or [2] above, wherein the aforementioned alkaline substance is one or more selected from the group consisting of alkali metal hydroxides and alkaline earth metal hydroxides.

[0023] [4] The deoxidizer composition according to any one of [1] to [3] above, wherein the aforementioned alkaline substance is calcium hydroxide.

[0024] [5] The deoxidizer composition according to any one of [1] to [4] above, wherein the aforementioned alkaline earth metal halide is selected from one or more of the group consisting of calcium chloride, magnesium chloride, magnesium bromide and calcium bromide.

[0025] [6] The deoxidizing agent composition according to any one of [1] to [5] above, wherein the aforementioned water-retaining carrier is one or more selected from the group consisting of diatomaceous earth, silica and activated carbon.

[0026] [7] The deoxidizer composition according to any one of [1] to [6] above, wherein the content of the aforementioned water-retaining carrier is 15 parts by mass or more and 50 parts by mass or less relative to the content of the aforementioned iron powder in 100 parts by mass.

[0027] [8] The deoxidizer composition according to any one of [1] to [7] above, wherein the content of the aforementioned water is 60 parts by mass or more and 370 parts by mass or less relative to the content of the aforementioned water-retaining carrier in 100 parts by mass.

[0028] [9] The deoxidizer composition according to any one of [1] to [8] above further comprises a thickener, which is one or more selected from the group consisting of calcium carboxymethyl cellulose, sodium carboxymethyl cellulose, calcium bentonite and sodium bentonite.

[0029]

[10] According to the deoxidizer composition described in [9] above, the content of the aforementioned thickener is 5 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the aforementioned water content.

[0030]

[11] An oxygen absorber packaging body comprising the oxygen absorber composition described in any one of [1] to

[10] above and a breathable packaging material containing the oxygen absorber composition.

[0031]

[12] A method for manufacturing a deoxidizer composition, which is a method for manufacturing the deoxidizer composition described in any one of [1] to

[10] above, the method comprising:

[0032] Step (I) yields a solution containing an alkaline earth metal halide, water, and one or more water-soluble solvents selected from the group consisting of 1 to 3 alcohols with a molecular weight of less than 100 (excluding polyether polyols) and polyethers with a number average molecular weight of less than 900.

[0033] Step (II) yields a mixture containing iron powder, a water-retaining carrier, and an alkaline substance; and

[0034] Step (III) involves mixing the aforementioned mixture with the aforementioned solution.

[0035] The effects of the invention

[0036] According to the present invention, it is possible to provide a deoxidizer composition that maintains moderate moisture activity while exhibiting excellent oxygen absorption and low hydrogen production, as well as a method for manufacturing the same, and a deoxidizer packaging. Detailed Implementation

[0037] The following will describe in detail the embodiments of the deoxidizer composition of the present invention, its manufacturing method, and the deoxidizer package.

[0038] It should be noted that in this specification, the term "A to B" related to the description of numerical values means "not less than A and not more than B" (when A < B) or "not more than A and not less than B" (when A > B). In addition, in the present invention, combinations of preferred embodiments are more preferred embodiments.

[0039] [Deoxidizer composition]

[0040] The deoxidizer composition of the present invention contains iron powder, a halide of an alkaline earth metal, water, an alkaline substance, a water-retaining carrier, and one or more water-soluble solvents selected from the group consisting of 1 to 3 yuan alcohols with a molecular weight of 100 or less (excluding polyether polyols) and polyethers with a number-average molecular weight of 900 or less. The content of the halide of the alkaline earth metal is 30 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the content of the water, and the content of the water-soluble solvent is 2 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the content of the water.

[0041] By having the above composition, the deoxidizer composition of the present invention can exhibit excellent oxygen absorption while maintaining a medium water activity, and can also inhibit the generation of hydrogen.

[0042] It should be noted that in this specification, "medium water activity" means that the water activity is within the range of "not less than 0.4 and not more than 0.6".

[0043] The reason why the deoxidizer composition of the present invention exhibits the above effects is not yet certain, but one of the reasons is considered as follows.

[0044] The deoxidizer composition of the present invention is characterized by containing one or more water-soluble solvents selected from the group consisting of 1 to 3 yuan alcohols with a molecular weight of 100 or less (excluding polyether polyols) and polyethers with a number-average molecular weight of 900 or less. It is considered that by containing the water-soluble solvent as defined above, the solubility of the reactant derived from the halide of the alkaline earth metal and the alkaline substance can be increased, and the precipitation of the reactant can be inhibited. As a result, it is considered that the water film on the surface of the iron powder can be maintained alkaline, the generation of hydrogen can be effectively inhibited, and the medium water activity of the deoxidizer composition can also be maintained.

[0045] Hereinafter, each component, etc. will be described.

[0046] (Iron powder)

[0047] The deoxidizer composition of the present invention contains iron powder.

[0048] In the deoxidizer composition of the present invention, iron powder is the main agent for the deoxidation reaction.

[0049] The type of iron powder is not particularly limited, but iron powder with exposed iron (metallic iron with zero valence) is preferred. It can also have an extremely thin oxide coating, similar to that of a conventional metal surface, without hindering the effects of the present invention. Specifically, reduced iron powder, electrolytic iron powder, and sprayed iron powder (atomized iron powder) are preferred. Additionally, pulverized or diced cast iron or similar materials can also be used.

[0050] Iron powder can be used alone or in combination with two or more types as needed. Furthermore, commercially available iron powders are readily available, and commercially available products can also be used.

[0051] From the viewpoint of ensuring good contact with oxygen, the average particle size (D50) of the iron powder is, for example, 3000 μm or less, preferably 1000 μm or less, more preferably 500 μm or less, and even more preferably 300 μm or less. Furthermore, from the viewpoint of suppressing dust generation, it is preferably 1 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. Specifically, the average particle size (D50) of the iron powder is preferably 1 to 1000 μm, more preferably 10 to 500 μm, and even more preferably 20 to 300 μm.

[0052] It should be noted that iron powder with an average particle size within the above-mentioned range can be obtained by appropriately selecting commercially available iron powder. Alternatively, it can be obtained by grading using a sieve corresponding to the desired average particle size.

[0053] The average particle size of the iron powder can be determined using the method described in the examples.

[0054] Furthermore, from the viewpoint of oxygen absorption, the specific surface area of ​​the iron powder is preferably 0.03 m². 2 / g or more, more preferably 0.05m 2 The concentration is 0.50 mg / g or more, and from the viewpoint of suppressing dust generation, it is preferably 0.50 mg / g. 2 / g or less, more preferably 0.20m 2 The specific surface area of ​​the iron powder is preferably below 0.03 to 0.50 m² / g. 2 / g, more preferably 0.05~0.20m 2 / g.

[0055] It should be noted that the specific surface area of ​​the iron powder can be determined using the method described in the examples.

[0056] The content of iron powder is not particularly limited, but in the deoxidizer composition, it is preferably 15% by mass or more and 75% by mass or less, more preferably 30% by mass or more and 60% by mass or less, and even more preferably 40% by mass or more and 55% by mass or less.

[0057] (Alkali earth metal halides)

[0058] The deoxidizer composition of the present invention comprises an alkaline earth metal halide.

[0059] The alkaline earth metal halides in the deoxidizer composition of the present invention catalyze the oxidation reaction of iron powder and enhance its activity. Furthermore, the alkaline earth metal halides prevent the water contained in the deoxidizer composition from evaporating and being lost from the composition, thus inhibiting the transfer of moisture to the preserved material.

[0060] In order for iron to absorb oxygen, moisture needs to be introduced to the surface of the iron, which utilizes the deliquescence phenomenon of metal salts.

[0061] Alkaline earth metal halides are deliquescent metal salts. Compared with alkali metal halides, they have higher solubility in water and can easily reduce water activity. Therefore, they are effective in preparing deoxidizer compositions (raw material powders) with moderate water activity.

[0062] It should be noted that the alkaline earth metal halides are preferably contained in the deoxidizer composition in the form of an aqueous solution dissolved in water.

[0063] There are no particular limitations on the halides of alkaline earth metals. Examples include chlorides, bromides, and iodides of alkaline earth metals. Preferably, one or more are selected from the group consisting of chlorides and bromides of alkaline earth metals.

[0064] In terms of processability and safety, the alkaline earth metal halide is preferably selected from one or more of the group consisting of calcium chloride, magnesium chloride, magnesium bromide and calcium bromide, more preferably selected from one or more of the group consisting of calcium chloride and magnesium chloride, and even more preferably calcium chloride.

[0065] Alkaline earth metal halides can be used alone or in combination of two or more as needed. Furthermore, the alkaline earth metal halides described above are readily available commercially, and commercially available products can also be used.

[0066] The content of alkaline earth metal halides relative to the water content is 30 parts by mass or more and 80 parts by mass or less per 100 parts by mass, preferably 40 parts by mass or more and 70 parts by mass or less, more preferably 50 parts by mass or more and 60 parts by mass or less. By setting it within the above range, a deoxidizer composition exhibiting moderate water activity, excellent oxygen absorption, and low hydrogen production can be obtained.

[0067] Furthermore, the content of alkaline earth metal halides in the deoxidizer composition is preferably 1% by mass or more and 40% by mass or less, more preferably 5% by mass or more and 20% by mass or less, and even more preferably 7% by mass or more and 15% by mass or less. Moreover, relative to 100 parts by mass of iron powder, the content of alkaline earth metal halides is 1 part by mass or more and 60 parts by mass or less, preferably 5 parts by mass or more and 40 parts by mass or less, and more preferably 10 parts by mass or more and 30 parts by mass or less.

[0068] (water)

[0069] The deoxidizer composition of the present invention contains water.

[0070] The water contained in the deoxidizer composition of the present invention is an essential component for carrying out the deoxidation reaction.

[0071] The water content is not particularly limited, but is preferably 60 parts by mass or more and 370 parts by mass or less relative to 100 parts by mass of the water-retaining carrier; more preferably 60 parts by mass or more and 200 parts by mass or less; even more preferably 65 parts by mass or more and 160 parts by mass or less; and even more preferably 70 parts by mass or more and 150 parts by mass or less. By setting the content within the above range, a deoxidizer composition exhibiting moderate water activity, excellent oxygen absorption, and low hydrogen production can be obtained.

[0072] Furthermore, the water content in the deoxidizer composition is preferably 1% by mass or more and 60% by mass or less, more preferably 5% by mass or more and 40% by mass or less, and even more preferably 10% by mass or more and 30% by mass or less. Moreover, relative to 100 parts by mass of iron powder, the water content is 10 parts by mass or more and 70 parts by mass or less, preferably 20 parts by mass or more and 55 parts by mass or less, and more preferably 30 parts by mass or more and 45 parts by mass or less.

[0073] (Alkaline substances)

[0074] The deoxidizer composition of the present invention contains an alkaline substance.

[0075] The alkaline substance in the deoxidizer composition of the present invention serves to maintain the surface of iron (especially the moisture present on this surface) as alkaline. Therefore, it is believed that on the surface of iron, during the oxygen absorption reaction, the concentration of hydrogen ions in the reaction water can be reduced, effectively inhibiting the reduction of hydrogen ions by iron to produce hydrogen.

[0076] The alkaline substance is not particularly limited, but is preferably selected from one or more of the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides and salts formed by weak acids and strong bases, more preferably one or more of the group consisting of alkali metal hydroxides and alkaline earth metal hydroxides, and even more preferably an alkaline earth metal hydroxide.

[0077] Examples of alkali metal hydroxides include potassium hydroxide and sodium hydroxide, with sodium hydroxide being the preferred choice.

[0078] Examples of hydroxides of alkaline earth metals include calcium hydroxide and magnesium hydroxide, with calcium hydroxide being the preferred choice.

[0079] Examples of salts formed from a weak acid and a strong base include phosphates, citrates, carbonates, and bicarbonates, with phosphates and citrates being preferred. Specific examples of salts formed from a weak acid and a strong base include trisodium phosphate, trisodium citrate, sodium bicarbonate, and sodium carbonate, with trisodium phosphate and trisodium citrate being preferred.

[0080] Alkaline substances can be used alone or in combination of two or more as needed. Furthermore, these alkaline substances are readily available commercially available products, and commercially available products can also be used.

[0081] It should be noted that the oxidation rate of iron is generally affected by pH, and there is a tendency for the oxidation rate of iron to decrease in the high pH range. Therefore, from the viewpoint of maintaining high oxygen absorption performance, calcium hydroxide (slaked lime), which has moderate solubility and can also function as a pH adjuster, is more preferably used as an alkaline substance.

[0082] The content of alkaline substances is not particularly limited, but is preferably 0.2 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of iron powder, more preferably 0.3 parts by mass or more and 5 parts by mass or less, and even more preferably 0.5 parts by mass or more and 3 parts by mass or less. By setting it within the above range, a deoxidizer composition exhibiting moderate moisture activity, excellent oxygen absorption, and low hydrogen production can be obtained.

[0083] In addition, the content of alkaline substances in the deoxidizer composition is preferably 0.05% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 5% by mass or less, and even more preferably 0.2% by mass or more and 1% by mass or less.

[0084] (Water-retaining carrier)

[0085] The deoxidizer composition of the present invention comprises a water-retaining carrier.

[0086] The water-retaining carrier in the deoxidizer composition of the present invention is a carrier that can be impregnated with water to carry (retain) water, and can supply the carried water to the surroundings, especially iron powder, as needed.

[0087] Such a water-retaining carrier is not particularly limited as long as it can retain water, and is preferably selected from one or more of the group consisting of porous materials and highly absorbent polymers, and more preferably porous materials.

[0088] Porous materials are any materials that have a porous structure and water retention function, such as diatomaceous earth, zeolite, sepiolite, quartz, porous glass, silica, activated clay, acid clay, activated carbon, vermiculite, and wood flour. Among them, one or more of the following are preferred: diatomaceous earth, silica, and activated carbon.

[0089] In particular, activated carbon is preferred in that it not only has the function of retaining water but also promotes the oxidation reaction of iron. The type of activated carbon is not particularly limited; wood, coconut shells, coal, etc., can all be used as raw materials for activated carbon. From the viewpoint of using the deoxidizing agent composition of the present invention in food, it is preferable to select one or more from the group consisting of wood and coconut shells.

[0090] Superabsorbent resins are any resins that can cause liquids such as water to solidify into a gel. Examples include polyacrylate resins, polysulfonate resins, polyacrylamide resins, polyvinyl alcohol resins, starch resins, cellulose resins, and polyalginate resins.

[0091] The aforementioned water-retaining carriers can be used individually or in combination of two or more as needed. Furthermore, these water-retaining carriers are readily available commercially available products, and commercially available products can also be used.

[0092] From the viewpoint of further improving the water retention function, the water retention carrier is preferably one or more selected from the group consisting of diatomaceous earth, silica and activated carbon, more preferably activated carbon and one or more selected from the group consisting of diatomaceous earth and silica, and even more preferably activated carbon and diatomaceous earth.

[0093] Furthermore, the properties of the water-retaining carrier are not particularly limited. From the viewpoint of processability when manufacturing the deoxidizer composition, it is preferable to use a powder-like substance with high flowability, and the particle shape of the water-retaining carrier is more preferably close to spherical.

[0094] Furthermore, from the viewpoint of processability when manufacturing the deoxidizer composition, the average particle size of the water-retaining carrier is preferably 0.05 μm or more and 1000 μm or less, more preferably 0.1 μm or more and 100 μm or less.

[0095] Especially when the water-retaining carrier is activated carbon, it is further preferred to be 1μm or more and 100μm or less, and even more preferably 1μm or more and 50μm or less.

[0096] Furthermore, when the water-retaining carrier is diatomaceous earth, it is even more preferable that the thickness is 0.2 μm or more and 50 μm or less, and even more preferably 0.2 μm or more and 10 μm or less.

[0097] As long as the particles of the water-retaining carrier have a particle size within the above-mentioned range, they can be used in the form of primary particles, aggregated particles, or granules. A water-retaining carrier with a particle size within the above-mentioned range can be used alone, or multiple carriers with different particle sizes can be mixed in any proportion. Such water-retaining carriers are readily available commercially and are easy to use.

[0098] It should be noted that the average particle size of the water-retaining carrier can be determined using the method described in the examples.

[0099] The content of the water-retaining carrier is not particularly limited, but is preferably 15 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass of iron powder, more preferably 20 parts by mass or more and 45 parts by mass or less, and even more preferably 25 parts by mass or more and 40 parts by mass or less. By setting it within the above range, a deoxidizer composition exhibiting moderate moisture activity, excellent oxygen absorption, and low hydrogen production can be obtained.

[0100] In addition, the content of the water-retaining carrier in the deoxidizer composition is preferably 1% or more and 40% or less by mass, more preferably 5% or more and 30% or less by mass, and even more preferably 10% or more and 20% or less by mass.

[0101] (Water-soluble solvent)

[0102] The deoxidizing agent composition of the present invention comprises one or more water-soluble solvents selected from the group consisting of 1 to 3 alcohols with a molecular weight of less than 100 (excluding polyether polyols) and polyethers with a number average molecular weight of less than 900.

[0103] The water-soluble solvent specified above in the deoxidizer composition of the present invention can increase the solubility of the reactants derived from alkaline earth metal halides and alkaline substances, thereby inhibiting the precipitation of the reactants.

[0104] Examples of 1- to 3-hydroxides with a molecular weight of 100 or less (excluding polyether polyols) include methanol, ethanol, propanol (1-propanol, 2-propanol), propylene glycol (1,2-propanediol, 1,3-propanediol), glycerol, butanol (1-butanol, 2-methyl-1-propanol, 2-butanol, 2-methyl-2-propanol), and butanediol (1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol). From the viewpoints of high oxygen absorption, ease of acquisition, and safety when used as a freshness preservative near food, one or more of the following are preferred: ethanol, propanol, propylene glycol, and glycerol. More preferably, one or more of the following are preferred: ethanol and glycerol. Ethanol is further preferred from the viewpoint of high oxygen absorption, and glycerol is further preferred from the viewpoint of inhibiting hydrogen production.

[0105] Examples of polyethers with a number average molecular weight of 900 or less include polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol. From the viewpoints of high oxygen absorption and ease of acquisition, it is preferable to select one or more from the group consisting of polyethylene glycol and polypropylene glycol, more preferably polyethylene glycol. It should be noted that there is no particular limitation on the number average molecular weight of the polyether as long as it is 900 or less, but it is preferably 600 or less, more preferably 500 or less, further preferably 400 or less, and preferably 200 or more.

[0106] In particular, the water-soluble solvent is preferably one or more selected from the group consisting of methanol, ethanol, propanol, propylene glycol, glycerol, butanol, butanediol, polyethylene glycol with a number average molecular weight of 900 or less, and polypropylene glycol with a number average molecular weight of 900 or less. More preferably, it is one or more selected from the group consisting of ethanol, propanol, propylene glycol, glycerol, polyethylene glycol with a number average molecular weight of 900 or less, and polypropylene glycol with a number average molecular weight of 900 or less. Even more preferably, it is one or more selected from the group consisting of ethanol, glycerol, and polyethylene glycol with a number average molecular weight of 900 or less. From the perspective of excellent hydrogen generation suppression effect, low cost, and easy management, glycerol is even more preferred.

[0107] A single water-soluble solvent can be used alone, or two or more can be used in combination as needed. Furthermore, the water-soluble solvents described above are readily available commercially available products, and commercially available products can also be used.

[0108] The content of the water-soluble solvent relative to the water content is 2 parts by mass or more and 80 parts by mass or less per 100 parts by mass, preferably 5 parts by mass or more and 75 parts by mass or less, more preferably 5 parts by mass or more and 65 parts by mass or less, even more preferably 10 parts by mass or more and 60 parts by mass or less, even more preferably 20 parts by mass or more and 60 parts by mass or less, and even more preferably 40 parts by mass or more and 60 parts by mass or less. By setting it within the above range, a deoxidizer composition exhibiting moderate water activity, excellent oxygen absorption, and low hydrogen production can be obtained.

[0109] Furthermore, the content of the water-soluble solvent in the deoxidizer composition is preferably 0.5% by mass or more and 30% by mass or less, more preferably 1% by mass or more and 15% by mass or less, even more preferably 1.5% by mass or more and 15% by mass or less, even more preferably 3% by mass or more and 15% by mass or less, and even more preferably 8% by mass or more and 15% by mass or less. Furthermore, relative to 100 parts by mass of iron powder, the content of the water-soluble solvent is preferably 0.5 parts by mass or more and 50 parts by mass or less, more preferably 1 part by mass or more and 25 parts by mass or less, even more preferably 3 parts by mass or more and 25 parts by mass or less, even more preferably 5 parts by mass or more and 25 parts by mass or less, and even more preferably 15 parts by mass or more and 25 parts by mass or less.

[0110] (Thickener)

[0111] The deoxidizer composition of the present invention preferably further comprises a thickener.

[0112] The thickener in the deoxidizer composition of the present invention is a substance that swells with water and has a binding function for maintaining the shape of the granules. Specifically, it increases the viscosity of the solution by dissolving or dispersing it in a liquid such as an aqueous solution.

[0113] Thickeners are preferably used in a substantially dry state or in a semi-swollen or swollen state that has absorbed a small or even necessary amount of water.

[0114] There are no particular limitations on such thickeners as long as they have a binding function. For example, in addition to the well-known swelling agents used in food, adhesives, binders, etc., can also be used.

[0115] In addition, the thickener can be either an inorganic thickener or an organic thickener.

[0116] Examples of inorganic thickeners include clay minerals such as sodium bentonite, calcium bentonite, and sodium montmorillonite. Clay minerals are preferred due to their low cost and excellent performance. In addition, inorganic soaps are also known as clay minerals and possess lubricant properties. Furthermore, clay minerals that swell with water are known to exhibit high thixotropy and excellent binding properties. Among these, bentonite-type minerals such as calcium bentonite and sodium bentonite are preferred from the viewpoint of low cost and strong binding force.

[0117] Examples of organic thickeners include organobentonite; natural products such as defatted frozen tofu, agar, starch, dextrin, gum arabic, gelatin, and casein; semi-synthetic products such as crystalline cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, calcium carboxymethyl cellulose, hydroxyethyl cellulose, lignin sulfonic acid, and hydroxyethylated starch; and synthetic products such as water-insoluble polyvinyl alcohol and polyvinyl methyl ether. Among these, from the viewpoint of exhibiting excellent swelling properties, cellulose-based semi-synthetic products such as crystalline cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, calcium carboxymethyl cellulose, and hydroxyethyl cellulose are preferred. From the viewpoint of being inexpensive and having strong binding power, carboxymethyl cellulose, sodium carboxymethyl cellulose, and calcium carboxymethyl cellulose are preferred.

[0118] The thickeners mentioned above can be used alone or in combination of two or more as needed. Furthermore, these thickeners are readily available commercially available products, and commercially available products can also be used.

[0119] The thickener is preferably one or more selected from the group consisting of clay minerals and cellulose-based semi-synthetic products. From the viewpoint of being inexpensive and having strong adhesion, it is more preferably one or more selected from the group consisting of bentonite and cellulose-based semi-synthetic products.

[0120] More specifically, the thickener is preferably one or more selected from the group consisting of calcium carboxymethyl cellulose, sodium carboxymethyl cellulose, calcium bentonite, and sodium bentonite.

[0121] The thickeners mentioned above can be used alone or in combination of two or more as needed. Furthermore, commercially available thickeners can be used.

[0122] From the viewpoint of suppressing dust generation and improving adhesion, the average particle size of the thickener is preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 50 μm or less, and even more preferably 10 μm or more and 50 μm or less.

[0123] It should be noted that the average particle size of the thickener can be determined using the method described in the examples.

[0124] The content of the thickener is not particularly limited, but is preferably 5 parts by mass or more and 20 parts by mass or less relative to 100 parts by mass of water, more preferably 10 parts by mass or more and 15 parts by mass or less. By setting it within the above range, a deoxidizer composition exhibiting moderate water activity, excellent oxygen absorption, and low hydrogen production can be obtained.

[0125] Furthermore, the content of the thickener in the deoxidizer composition is preferably 0.5% by mass or more and 10% by mass or less, more preferably 1% by mass or more and 5% by mass or less. Moreover, relative to 100 parts by mass of iron powder, the content of the thickener is preferably 0.5 parts by mass or more and 20 parts by mass or less, more preferably 1 part by mass or more and 10 parts by mass or less.

[0126] (Other ingredients)

[0127] In addition to the above-mentioned components, the deoxidizer composition of the present invention may also contain other components as needed. Examples of other components include flowability improvers, catalysts, odor adsorbents, and heat dispersants.

[0128] <Shape of the deoxidizer composition>

[0129] The shape of the deoxidizer composition of the present invention is not particularly limited, but it is preferably granular.

[0130] Here, granules can be aggregated particles or granules.

[0131] Furthermore, as for particle shape, examples include spherical, approximately spherical, elliptical, and cylindrical. From the perspective of having better filling properties and higher bulk density, spherical and approximately spherical shapes are preferred, and spherical shapes are more preferred.

[0132] The average particle size of the deoxidizer composition of the present invention is not particularly limited, but is preferably 0.3 mm or more and 5.0 mm or less, more preferably 0.5 mm or more and 2.0 mm or less. By making the average particle size 0.3 mm or more, it is possible to suppress the adhesion of powder particles to the contact portion of the packaging machine due to static electricity or the like during filling and packaging. In addition, by making the average particle size 5.0 mm or less, it is possible to prevent the gaps between particles from becoming too large and the oxygen absorption per unit volume from decreasing. In order to obtain a deoxidizer composition with an average particle size in the above range, for example, it can be sieved using sieves with a mesh size of 0.3 mm and 5.0 mm.

[0133] It should be noted that the average particle size of the deoxidizer composition can be determined by the method described in the examples.

[0134] <Characteristics of Deoxidizer Compositions>

[0135] The deoxidizer composition of the present invention preferably exhibits moderate moisture activity.

[0136] The closer the water activity value is to 1, the closer the water vapor pressure of the water evaporated from the deoxidizer composition is to the water vapor pressure of pure water.

[0137] The deoxidizer composition of the present invention has a water activity of so-called medium water activity, preferably 0.40 or more and 0.60 or less, more preferably 0.45 or more and 0.60 or less, and even more preferably 0.47 or more and 0.59 or less.

[0138] It should be noted that there are no particular limitations on the method for determining water activity. Known equipment such as dew point water activity meters can be used for the determination. Specifically, the method described in the examples can be used for the determination.

[0139] Generally, when items are stored in a sealed state, the greater the difference in water activity between the stored item and the deoxidizer composition, the easier it is for water transfer to occur. Therefore, from the viewpoint of inhibiting water transfer, the water activity of the deoxidizer composition is preferably the same as that of the stored item.

[0140] The deoxidizer composition of the present invention exhibits moderate water activity and is therefore suitable for the preservation of substances exhibiting moderate water activity.

[0141] Examples of items suitable for preservation using the deoxidizing agent composition of the present invention include, for instance, food products such as rice / grains, spices, bonito flakes, dried small fish, and seaweed; industrial products such as electronic components with solder joints, metal screws, and metal knives such as razors; pharmaceuticals such as compressed tablets, raw herbs, and active ingredients that are susceptible to hydrolysis; and various other articles. Among these, it is particularly suitable for the preservation of pharmaceuticals.

[0142] [Method for manufacturing the deoxidizer composition]

[0143] The method for manufacturing the deoxidizer composition of the present invention is not particularly limited, but preferably includes a step of mixing iron powder, an alkaline earth metal halide, water, an alkaline substance, a water-retaining carrier, and one or more water-soluble solvents selected from the group consisting of 1 to 3 alcohols with a molecular weight of 100 or less (excluding polyether polyols) and polyethers with a number average molecular weight of 900 or less.

[0144] According to this manufacturing method, granules are prepared by mixing iron powder, alkaline earth metal halides, water, alkaline substances, water-retaining carriers and specified water-soluble solvents until they are uniformly dispersed, and deoxidizer compositions can be prepared efficiently.

[0145] The mixing process described above is not particularly limited. It can be (1) a process of mixing all the components together, or (2) a process of preparing a mixture in advance by dividing it into several components and then mixing the mixture together.

[0146] A more preferred method for manufacturing the deoxidizer composition of the present invention includes: step (I), obtaining a solution comprising an alkaline earth metal halide, water, and one or more water-soluble solvents selected from the group consisting of 1 to 3 alcohols with a molecular weight of 100 or less (excluding polyether polyols) and polyethers with a number average molecular weight of 900 or less; step (II), obtaining a mixture comprising iron powder, a water-retaining carrier, and an alkaline substance; and step (III), mixing the aforementioned mixture with the aforementioned solution.

[0147] It is believed that this manufacturing method can yield a more homogeneous deoxidizer composition, and in particular, can effectively suppress the precipitation of halides and reactants derived from alkaline earth metals.

[0148] There are no particular limitations on the mixing method; it can be carried out by oscillation mixing, mixing using a mixing device, etc. Specific examples of mixing devices include NAUTA mixers (manufactured by Hosokawa Micron Corporation), conical mixers (manufactured by Ohno Chemical Machinery Co., Ltd.), vertical granulators (manufactured by POWREXCORP.), high-speed mixers (manufactured by EARTHTECHNICACo., Ltd.), and granulators (manufactured by AKIRAKIKO co., Ltd.).

[0149] Iron, as the main deoxidizer, reacts with oxygen, and therefore the reaction proceeds slowly even in the absence of water, alkaline earth metal halides, etc. Therefore, mixing is preferably carried out in an inert atmosphere (in the case of a essentially closed system, the system is usually set to an oxygen-free, inert gas atmosphere (e.g., N2)), and appropriate heat removal measures are taken.

[0150] [Oxygen absorber packaging]

[0151] The deoxidizer packaging of the present invention comprises the above-described deoxidizer composition and a breathable packaging material containing the deoxidizer composition.

[0152] (Packaging materials)

[0153] As packaging materials, examples include pouches made by laminating two breathable packaging materials together, pouches made by laminating one breathable packaging material and one non-breathable packaging material together, and pouches made by bending one breathable packaging material and sealing the edges (excluding the bent portion) together.

[0154] Here, when both the breathable and non-breathable packaging materials are quadrilateral in shape, the packaging materials can be categorized as follows: (1) Two breathable packaging materials are overlapped and heat-sealed on all four sides to form a bag; (2) One breathable packaging material and one non-breathable packaging material are overlapped and heat-sealed on all four sides to form a bag; (3) One breathable packaging material is bent and three sides other than the bent portion are heat-sealed to form a bag. Alternatively, the packaging material can also be made by forming a breathable packaging material into a cylindrical shape and heat-sealing both ends and the main body of the cylindrical body to form a bag.

[0155] (Breathable packaging materials)

[0156] As a breathable packaging material, a packaging material that allows for the permeability of oxygen and carbon dioxide is selected. Preferably, a material with a permeability resistance of 40,000 seconds or less, more preferably 30,000 seconds or less, further preferably 20,000 seconds or less, even more preferably 10,000 seconds or less, and more preferably 500 seconds or more, more preferably 1,000 seconds or more, based on the Wang Yan test machine method, is used. Here, permeability resistance refers to the value measured by the method of JIS P8117:2009. More specifically, it can be measured by the method described in the examples.

[0157] In addition to paper and nonwoven fabric, materials that impart breathability to plastic films can also be used as the aforementioned breathable packaging materials. For example, laminated films can be made by laminating films of polyethylene terephthalate, polyamide, polypropylene, polycarbonate, etc., with films of polyethylene, ionomer, polybutadiene, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, or ethylene-vinyl acetate copolymer, etc., as sealing layers. Furthermore, these laminates can also be used as breathable packaging materials; for example, laminates such as linear low-density polyethylene porous film / paper / polyethylene terephthalate porous film can be appropriately used.

[0158] In addition to cold needle and hot needle perforation, various other methods can be used to impart breathability. When perforation is used to impart breathability, the breathability can be freely adjusted by the diameter, number, and material of the perforations.

[0159] Furthermore, the thickness of the laminated film is preferably 30 μm or more and 300 μm or less, more preferably 40 μm or more and 250 μm or less. In this case, compared with cases where the thickness deviates from the above range, it is possible to produce a packaging material that maintains strength and has excellent heat-sealing properties and packaging suitability.

[0160] (Uses of deoxidizer packaging)

[0161] The deoxidizer packaging of the present invention contains the deoxidizer composition of the present invention, thus exhibiting moderate moisture activity, excellent oxygen absorption, and low hydrogen production. Therefore, it is suitable for the preservation of items exhibiting moderate moisture activity.

[0162] Specifically, the deoxidizer packaging of the present invention is suitable for a method of deoxidizing the internal space of an air-barrier container containing a preserved item exhibiting moderate moisture activity. According to this method, the transfer of moisture from the deoxidizer packaging to the preserved item can be suppressed, thereby enabling efficient deoxidation of the internal space of the air-barrier container and thus maintaining the quality of the preserved item well.

[0163] Furthermore, when using the oxygen absorber packaging body of the present invention, it is preferable to manufacture a packaging body comprising the oxygen absorber packaging body, the preserved item, and an air-barrier container for containing them. In this case, from the viewpoint of maintaining the quality of the preserved item, the humidity inside the air-barrier container is preferably 40% RH or higher and 60% RH or lower. Additionally, the preserved item is preferably one or more selected from the group consisting of food, industrial products, and pharmaceuticals, more preferably pharmaceuticals.

[0164] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, including all the concepts of the present invention and all the ways contained in the claims, and various changes can be made within the scope of the present invention.

[0165] Example

[0166] The following examples and comparative examples are used to describe this embodiment in detail. This embodiment can be modified appropriately as long as the effect of the present invention is achieved.

[0167] <Materials>

[0168] The following shows the materials used in the embodiments and comparative examples.

[0169] Iron powder: average particle size 100μm, specific surface area 0.104m² 2 / g

[0170] • Calcium chloride (CaCl2): Manufactured by Fujifilm and Koko Pure Chemical Industries, Ltd., premium reagent grade.

[0171] • Calcium hydroxide (Ca(OH)2): Manufactured by Fujifilm and Wako Pure Chemical Industries, Ltd., premium reagent grade.

[0172] • Activated carbon: "White Egret A" manufactured by Osaka Gas Chemicals Co., Ltd., in powder form, with an average particle size of 10 μm.

[0173] Diatomaceous earth: Isolite Insulating Products Co., Ltd. manufactures "CG-2U", powder form, average particle size 0.44μm.

[0174] • Calcium bentonite: Kunimine Industries Co., Ltd. manufactures "Neokunibond" with an average particle size of 32.7 μm, referred to as "bentonite" in Table 2.

[0175] • Sodium carboxymethyl cellulose: Nippon Paper Chemical Co., Ltd. "Sunrose F350HC-4", average particle size 29μm, indicated as "CMC" in Table 2.

[0176] • Glycerin: Manufactured by Fujifilm and Wako Pure Chemical Industries, Ltd., Premium Reagent Grade

[0177] • Polyethylene glycol 400: Manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd., Wako Grade I, number average molecular weight 360-440 (catalog value), hereinafter referred to as "PEG400".

[0178] • Polyethylene glycol 1000: Manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd., Wako Grade 1, number average molecular weight 900-1100 (catalog value), hereinafter referred to as "PEG1000".

[0179] • Polyethylene glycol 4000: Manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd., Wako Grade 1, number average molecular weight 2700-3300 (catalog value), hereinafter referred to as "PEG4000".

[0180] • Ethanol (99.5%): Manufactured by Fujifilm and Wako Pure Chemical Industries, Ltd., Premium Reagent Grade

[0181] • D(-)-Sorbitol: Manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd., Wako Grade I, hereinafter referred to as "Sorbitol".

[0182] • Breathable packaging material A: Bag-shaped with external dimensions of 40mm × 30mm

[0183] Breathable packaging material A uses linear low-density polyethylene (porous film, 30μm thick, hereinafter referred to as "LLDPE") / nylon paper (50g / m²). 2 It is made of a multilayer sheet (52μm thick, air permeability resistance 5300 seconds) with the LLDPE as the inside, and the three sides are heat-sealed with a sealing width of 5mm so that one side is an opening.

[0184] • Breathable packaging material B: Bag-shaped with external dimensions of 100mm × 70mm

[0185] The breathable packaging material B is made of a multi-layer sheet (thickness 39μm, air resistance 10 seconds) with LLDPE (same as above) / paper (same as above) structure, bent with LLDPE as the inside, and three sides are heat-sealed with a sealing width of 5mm so that one side is the opening.

[0186] <Determination Method>

[0187] The above-mentioned physical properties were determined by the following methods.

[0188] [Determination of the average particle size of iron powder]

[0189] Regarding the average particle size of the iron powder mentioned above, the average particle size (D50) at 50% cumulative frequency was determined using a standard sieve according to ISO 3310-1:2000 (equivalent to JIS Z8801-1:2006) based on the weight fraction of the sieve aperture size after 5 minutes of vibration.

[0190] [Specific surface area of ​​iron powder]

[0191] The specific surface area of ​​the above iron powder (unit: m²) 2 / g) Determined according to JIS Z8830:2013, based on the BET multi-point method.

[0192] [Average particle size of components other than iron powder]

[0193] The average particle size of components other than iron powder was measured using a laser diffraction-scattering particle size distribution measuring device (LA-960 manufactured by Horiba Manufacturing Co., Ltd.) to determine the average particle size (D50) of the cumulative frequency in the volume reference particle size distribution.

[0194] [Breathability and resistance of multi-layered sheets]

[0195] The air permeability resistance of the above-mentioned multilayer sheets was measured three times using a digital Oki-type air permeability tester (manufactured by Asahi Seiko Co., Ltd., "EG02"). The arithmetic mean of the results was taken as the final measurement result.

[0196] <Deoxidizer Composition and Preparation of Deoxidizer Packaging Using the Same>

[0197] (Example 1)

[0198] [1] Preparation of deoxidizer composition

[0199] First, 16.1 g of calcium chloride (CaCl2), an alkaline earth metal halide, was dissolved in 29.6 g of water to prepare an aqueous solution of calcium chloride. Next, 1.6 g of glycerol, a 1-3 boron alcohol with a molecular weight of less than 100, was added to this aqueous solution of calcium chloride and stirred to prepare an aqueous solution of calcium chloride and glycerol.

[0200] Next, 80.0g of iron powder, 15.1g of diatomaceous earth as a water-retaining carrier, 7.4g of activated carbon, 0.8g of calcium hydroxide (Ca(OH)2) as an alkaline substance, 3.0g of calcium bentonite as a thickener, and 0.3g of sodium carboxymethyl cellulose were placed into a 300ml plastic container and shaken to mix, thus obtaining a mixture.

[0201] Next, the above-mentioned calcium chloride-glycerol aqueous solution was added to the mixture, and the mixture was further shaken and mixed to obtain the deoxidizer composition.

[0202] It should be noted that the obtained deoxidizer composition is a granular material formed by the aggregation of powdered particles (average particle size 1.60 mm).

[0203] [Average particle size of the deoxidizer composition]

[0204] The average particle size of the above-mentioned deoxidizer composition was determined by a laser diffraction-scattering particle size distribution measuring device (as above) to measure the average particle size (D50) of the cumulative frequency in the volume reference particle size distribution.

[0205] [2] Production of deoxidizer packaging

[0206] [2-1] Preparation of deoxidizer packaging A (sample for determining oxygen absorption)

[0207] After filling 0.8g of the deoxidizer composition prepared in [1] into the breathable packaging material A, the opening is heat-sealed with a sealing width of 5mm to make a bag-shaped deoxidizer packaging body A.

[0208] It should be noted that for the deoxidizer packaging A, until the oxygen absorption is measured, it is placed in a low oxygen permeability gas barrier bag (manufactured by Fukusuke Kogyo Co., Ltd., made of barrier nylon and LLDPE laminate), and the opening is heat-sealed to prevent it from reacting with oxygen in the atmosphere.

[0209] [2-2] Preparation of deoxidizer packaging B (sample for hydrogen production determination)

[0210] After filling 25g of the deoxidizer composition prepared in [1] into the breathable packaging material B, the opening is heat-sealed with a sealing width of 5mm to make a bag-shaped deoxidizer packaging body B.

[0211] It should be noted that for the prepared deoxidizer packaging body B, until the hydrogen production is measured, it should be placed in a gas barrier bag with low oxygen permeability (as above), and the opening should be heat-sealed to prevent it from reacting with oxygen in the atmosphere.

[0212] (Examples 2-4)

[0213] In Examples 2-4, the amount of glycerol was changed to the values ​​shown in Table 1. Otherwise, the deoxidizer composition and deoxidizer packaging bodies A and B were prepared by the same method as in Example 1.

[0214] (Examples 5 and 6)

[0215] In Examples 5 and 6, instead of glycerol, PEG400, a polyether with a number average molecular weight of less than 900, was used at the mixing amounts shown in Table 1. Otherwise, the deoxidizer compositions and deoxidizer packages A and B were prepared by the same method as in Example 1.

[0216] (Examples 7 and 8)

[0217] In Examples 7 and 8, instead of glycerol, ethanol, a 1-3 alcohol with a molecular weight of less than 100, was used in the mixing amounts shown in Table 1. Otherwise, the deoxidizer composition and deoxidizer packaging bodies A and B were prepared by the same method as in Example 1.

[0218] (Comparative Example 1)

[0219] In Comparative Example 1, no water-soluble solvent was used. Otherwise, the deoxidizer composition and deoxidizer packaging bodies A and B were prepared by the same method as in Example 1.

[0220] (Comparative Example 2)

[0221] In Comparative Example 2, sorbitol, a 6-membered water-soluble alcohol, was used instead of glycerol. Otherwise, the deoxidizer composition and deoxidizer packaging bodies A and B were prepared by the same method as in Example 1.

[0222] (Compare Examples 3 and 4)

[0223] In Comparative Examples 3 and 4, instead of glycerol, PEG1000 and PEG4000, which are polyethers with a number average molecular weight of 1000 or higher, were used to attempt to prepare deoxidizer compositions in the mixing amounts shown in Table 1. However, when the specified amounts of PEG1000 or PEG4000 were added to the calcium chloride aqueous solution and stirred, a high-viscosity cream-like consistency was formed at room temperature (25°C), and a liquid aqueous solution could not be obtained. Therefore, PEG1000 and PEG4000 were determined to be unsuitable materials for use as deoxidizer compositions, and subsequent operations were discontinued.

[0224] <Evaluation>

[0225] The following evaluation was conducted using the deoxidizer compositions prepared in Examples 1-8 and Comparative Examples 1 and 2, as well as deoxidizer packages A and B. The results are shown in Table 1.

[0226] (Moisture activity)

[0227] The determination of water activity was carried out using the deoxidizer composition prepared in [1] above by the following method.

[0228] First, place 1.0g of the deoxidizer composition into a special petri dish and use a water activity assay device (METER "AquaLab TDL 2") at 25°C according to the steps specified by the device.

[0229] The above determination was performed three times, and the arithmetic mean of the results was used as the water activity value of the deoxidizer composition of each example or comparative example for evaluation.

[0230] In this embodiment, a water activity value between 0.40 and 0.60 (medium water activity) is defined as good, and a value close to 0.50 (the middle value) is evaluated as even better. It should be noted that the water activity values ​​in Table 1 are rounded to three decimal places for evaluation.

[0231] (Oxygen uptake)

[0232] The oxygen absorption was determined using the deoxidizer packaging A prepared in [2-1] above, by the following method.

[0233] First, one oxygen absorber package A and 1500ml of air at 25°C are placed together in an air-barrier bag made of nylon / polyethylene laminated film (manufactured by Fukusuke Kogyo Co., Ltd., size 250mm × 400mm, oxygen permeability 7.3ml / m³). 2 (day·atm), the opening is heat-sealed to seal it. Then, the oxygen concentration inside the gas-barrier bag at this time (initial oxygen concentration) is measured.

[0234] Then, the gas-barrier bag was quickly placed in a constant temperature bath at 25°C and kept there for 7 days. The oxygen concentration inside the gas-barrier bag (post-storage oxygen concentration) was measured at 1, 3, and 7 days, and the oxygen absorption (initial oxygen concentration - post-storage oxygen concentration) was calculated. Furthermore, the calculated oxygen absorption was divided by the mass of iron powder in the deoxidizer composition (in g) to calculate the oxygen absorption per unit mass of iron powder at each time point (in ml / 1g of iron powder).

[0235] It should be noted that the oxygen concentration was measured using a gas analyzer (MOCON "Check Mate 3"). The measurement was performed as follows: the hollow needle at the front end of the sampling silicone tube attached to the gas analyzer was inserted into the inside of the sampling rubber sheet (25mm×25mm, 2mm thick) pre-attached to the gas barrier bag, and the oxygen concentration inside the gas barrier bag was measured.

[0236] The above measurements were performed three times at each time point, and the arithmetic mean of the results was used to evaluate the oxygen absorption capacity of the deoxidizer compositions of each example or comparative example. Higher oxygen absorption capacity indicates better oxygen absorption performance.

[0237] In this embodiment, iron powder with an oxygen absorption of 190.0 ml / 1g of iron powder per unit mass after 3 days is evaluated as good, and iron powder with an oxygen absorption of 200.0 ml / 1g of iron powder per unit mass or more is evaluated as even better. Furthermore, from the viewpoint that it can rapidly exert its oxygen absorption capacity even in a short period of time, iron powder with an oxygen absorption of 130.0 ml / 1g of iron powder per unit mass after 1 day is evaluated as even better.

[0238] (Hydrogen production)

[0239] The amount of hydrogen produced was determined using the deoxidizer packaging B prepared in [2-2] above, by the following method.

[0240] First, one oxygen absorber package B, along with 25 ml of air at 35°C, is placed in an air-barrier bag made of nylon / aluminum foil / polyethylene laminated film (manufactured by Meiwa Pax, dimensions 175mm × 250mm, oxygen permeability 0.1 ml / m³). 2 For meters below 1000 meters, the opening is sealed by heat sealing.

[0241] Then, the gas barrier bag was quickly placed in a constant temperature bath at 35°C and kept there for 72 hours. The hydrogen concentration inside the gas barrier bag was then determined by gas chromatography, and the hydrogen production amount (unit: ml) was calculated. Furthermore, the calculated hydrogen production amount was divided by the mass of iron powder in the deoxidizer composition (unit: g) to calculate the hydrogen production per unit mass of iron powder (unit: ml / 1g iron powder).

[0242] It should be noted that the hydrogen concentration was measured using a gas chromatograph (GC-14A manufactured by Shimadzu Corporation).

[0243] The above measurements were performed three times, and the arithmetic mean of the results was used to evaluate the hydrogen production of the deoxidizer compositions of each example or comparative example. Lower hydrogen production indicates more effective suppression of hydrogen generation. In this example, a hydrogen production of 0.020 ml / 1 g of iron powder per unit mass was evaluated as good.

[0244] It should be noted that deoxidizer package B was manufactured in a manner more suitable for evaluating hydrogen production.

[0245] [Table 1]

[0246] Table 1

[0247]

[0248] It should be noted that the formulations of the deoxidizer compositions prepared in Examples 1-8 and Comparative Examples 1 and 2 are shown in Table 2 below. It should also be noted that although no deoxidizer compositions were obtained in Comparative Examples 3 and 4, their formulations are as shown in Table 2 below.

[0249] [Table 2]

[0250] Table 2

[0251]

[0252] As shown in Table 1, deoxidizer compositions containing iron powder, alkaline earth metal halides, water, alkaline substances, water-retaining carriers, and specified water-soluble solvents, with the contents of alkaline earth metal halides and specified water-soluble solvents within specified ranges, were found to exhibit moderate water activity, excellent oxygen absorption, and low hydrogen production (Examples 1-8).

[0253] On the other hand, in the case where no water-soluble solvent is present (Comparative Example 1), and the water-soluble solvent is not a specific component specified in this invention but is sorbitol (Comparative Example 2), it was confirmed that the amount of hydrogen generated was high and the amount of oxygen absorbed was low.

[0254] In addition, as mentioned above, it was confirmed that PEG1000 and PEG4000, whose water-soluble solvents are not specific components specified in this invention, are not suitable as materials for deoxidizer compositions (Comparative Examples 3 and 4).

Claims

1. A deoxidizer composition comprising iron powder, an alkaline earth metal halide, water, an alkaline substance, a water-retaining carrier, and one or more water-soluble solvents selected from the group consisting of 1-3 alcohols with a molecular weight of less than 100 and polyethers with a number average molecular weight of less than 900, wherein... Polyether polyols are excluded if they are 1- to 3-hydrone alcohols with a molecular weight below 100. The content of the alkaline earth metal halide is more than 30 parts by mass and less than 80 parts by mass per 100 parts by mass of water. The content of the water-soluble solvent is more than 2 parts by mass and less than 80 parts by mass relative to the content of water (100 parts by mass).

2. The deoxidizer composition according to claim 1, wherein, The water-soluble solvent is selected from one or more of the group consisting of methanol, ethanol, propanol, propylene glycol, glycerol, butanol, butanediol, polyethylene glycol with a number average molecular weight of less than 900, and polypropylene glycol with a number average molecular weight of less than 900.

3. The deoxidizer composition according to claim 1 or 2, wherein, The alkaline substance is one or more selected from the group consisting of hydroxides of alkali metals and hydroxides of alkaline earth metals.

4. The deoxidizer composition according to any one of claims 1 to 3, wherein, The alkaline substance is calcium hydroxide.

5. The deoxidizer composition according to any one of claims 1 to 4, wherein, The alkaline earth metal halide is selected from one or more of the group consisting of calcium chloride, magnesium chloride, magnesium bromide and calcium bromide.

6. The deoxidizer composition according to any one of claims 1 to 5, wherein, The water-retaining carrier is selected from one or more of the group consisting of diatomaceous earth, silica and activated carbon.

7. The deoxidizer composition according to any one of claims 1 to 6, wherein, The content of the water-retaining carrier is 15 parts by mass or more and 50 parts by mass or less per 100 parts by mass relative to the content of the iron powder.

8. The deoxidizer composition according to any one of claims 1 to 7, wherein, The water content is between 60 and 370 parts by mass relative to 100 parts by mass of the water-retaining carrier.

9. The deoxidizer composition according to any one of claims 1 to 8, further comprising a thickener, the thickener being one or more selected from the group consisting of calcium carboxymethyl cellulose, sodium carboxymethyl cellulose, calcium bentonite, and sodium bentonite.

10. The deoxidizer composition according to claim 9, wherein, The content of the thickener is more than 5 parts by mass and less than 20 parts by mass relative to the content of water (100 parts by mass).

11. A deoxidizer packaging body comprising the deoxidizer composition according to any one of claims 1 to 10 and a breathable packaging material containing the deoxidizer composition.

12. A method for manufacturing a deoxidizer composition, comprising the method of manufacturing the deoxidizer composition according to any one of claims 1 to 10, the method comprising: Step I yields a solution containing an alkaline earth metal halide, water, and one or more water-soluble solvents selected from the group consisting of 1-3 alcohols with a molecular weight of less than 100 and polyethers with a number average molecular weight of less than 900, wherein 1-3 alcohols with a molecular weight of less than 100 exclude polyether polyols. Step II yields a mixture containing iron powder, a water-retaining carrier, and an alkaline substance; and Step III: Mix the mixture with the solution.

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