Deoxidizer composition and method for manufacturing the same

Abstract

A deoxidizer composition comprising a mixed granulate of a composition containing a water retention agent, a swelling agent, a metal salt, water, and iron, and a method for manufacturing a deoxidizer composition, which includes a step of mixing the water retention agent, the swelling agent, the metal salt, water, and iron together to granulate.

Description

Technical Field

[0001] The present invention relates to a deoxidizer composition and a method for producing the same, and more particularly to an iron-based deoxidizer composition and a method for producing the same. Background Art

[0002] As a preservation technique for foods, drugs, etc., a method using a deoxidizer is known. When using this method, by enclosing an article to be preserved and a deoxidizer in an airtight container having gas barrier properties and sealing it, the deoxidizer absorbs oxygen in the sealed container, and the atmosphere in the sealed container can be substantially maintained in an anaerobic state. As a function of the deoxidizer, it is required to be small-sized and absorb a large amount of oxygen. In other words, a deoxidizer composition having a high oxygen absorption amount per unit volume is required.

[0003] As representative deoxidizers, an iron-based deoxidizer having iron (iron powder) as a main agent, and a non-iron-based deoxidizer having ascorbic acid, glycerin, etc. as main agents can be cited. The deoxidizer is appropriately selected according to the use, but from the viewpoint of oxygen absorption performance, an iron-based deoxidizer is widely used.

[0004] Iron powder requires moisture in order to absorb oxygen. For conventional deoxidizers containing iron powder and water, the iron powder and the water-retaining agent that retains and supplies moisture are contained in the form of different powder particles that can be separated from each other. Therefore, a gap is generated between the powder particles of the iron powder and the water-retaining agent, and this gap is one of the reasons for the reduction in the oxygen absorption amount per unit volume of the deoxidizer composition. In addition, for the iron powder and the water-retaining agent, they are likely to aggregate and bond to each other between the iron powders or between the water-retaining agents to form lumps. If the iron powder forms lumps, the surface area of the iron powder that can be oxidized decreases, and thus there is a problem of a reduction in the oxygen absorption amount as compared with the case where the iron powder and the water-retaining agent are uniformly dispersed and mixed.

[0005] For example, Patent Document 1 discloses a deoxidizer composition containing an oxygen-absorbing substance, water, and a swelling agent, which is solidified by pressure molding, thereby eliminating the gaps between the powder particles, reducing the volume, and achieving compactification. However, the deoxidizer composition as described in Patent Document 1 requires a new process of pressure molding as compared with a deoxidizer composition that can be produced only by mixing, and thus the manufacturing cost increases. In addition, the iron powder deeper inside the powder particles is more difficult to oxidize, and thus there is room for improvement in the oxygen absorption amount per unit volume.

[0006] The object of Patent Document 2 is to solve the problems in the deoxidizer composition of Patent Document 1 and provide a deoxidizer composition having excellent oxygen absorption amount per unit volume, and discloses a deoxidizer composition containing powder particles having an α layer containing a water-retaining agent, a swelling agent, a metal salt, and water, a β layer containing iron, and a γ layer containing a porous carrier, and the powder particles form a layer structure in the order of the α layer, the β layer, and the γ layer from the inside to the outside of the powder particles.

[0007] Prior art documents

[0008] Patent documents

[0009] Patent document 1: WO 2007 / 046449

[0010] Patent document 2: WO 2017 / 169015 Summary of the invention

[0011] Problems to be solved by the invention

[0012] From the viewpoint of preventing oxidation of the stored article in a sealed container, a deoxidizer that can absorb oxygen in the sealed container as quickly as possible is sought. In addition, the deoxidizer of Patent Document 2 requires the following manufacturing process: while mixing a water retention agent and a swelling agent, an aqueous solution of a metal halide salt is added to produce a powder as a raw material for the α layer, and then iron powder is added to the powder so that the iron powder adheres to the outside of the α layer, thereby producing (α layer / β layer) powder. A method for more effectively manufacturing a deoxidizer is sought.

[0013] Therefore, an object of the present invention is to provide a deoxidizer composition having a high oxygen absorption rate at the initial stage of the oxidation reaction of iron. Another object of the present invention is to provide a method for effectively manufacturing a deoxidizer composition having a high oxygen absorption rate at the initial stage of the oxidation reaction of iron.

[0014] Solutions to the problems

[0015] The present invention relates to the following deoxidizer composition and its manufacturing method.

[0016] <1> A deoxidizer composition comprising a mixed granulate of a composition containing a water retention agent, a swelling agent, a metal salt, water, and iron.

[0017] <2> The deoxidizer composition according to <1> above, wherein the average particle size is 0.3 mm or more and 5.0 mm or less.

[0018] <3> The deoxidizer composition according to <1> or <2> above, wherein a layer containing a porous carrier is provided on the outside of the mixed granulate.

[0019] <4> The deoxidizer composition according to any one of <1> to <3> above, wherein the water retention agent contains at least one selected from the group consisting of diatomaceous earth, silica, and activated carbon.

[0020] <5> The deoxidizer composition according to any one of <1> to <4> above, wherein the swelling agent contains at least one selected from the group consisting of calcium carboxymethylcellulose, sodium carboxymethylcellulose, calcium bentonite, and sodium bentonite.

[0021] <6>The deoxidizer composition according to any one of <1> to <5> above, wherein the mixed granulated product is not a compression-molded product.

[0022] <7>The deoxidizer composition according to any one of <1> to <6> above, wherein iron is dispersed throughout the mixed granulated product.

[0023] <8>A method for producing a deoxidizer composition, which is a method for producing the deoxidizer composition according to any one of <1> to <7> above, and which includes a step of mixing a water retention agent, a swelling agent, a metal salt, water, and iron together for granulation.

[0024] <9>A deoxidizer package, which includes the deoxidizer composition according to any one of <1> to <7> above and a breathable packaging material for containing the deoxidizer composition.

[0025] Effects of the Invention

[0026] In the deoxidizer composition of the present invention, the oxygen absorption rate at the initial stage of the oxidation reaction of iron is fast, and the oxygen in the closed container can be absorbed in a short time. In addition, according to the production method of the present invention, a deoxidizer composition with a fast oxygen absorption rate at the initial stage of the oxidation reaction of iron and capable of absorbing the oxygen in the closed container in a short time can be effectively produced. Detailed Embodiments

[0027] An embodiment of the present invention will be described below. The content of the present invention is not limited by the embodiments described below.

[0028] It should be noted that in this specification, the term "A to B" for the description of numerical values means "A or more and B or less" (when A < B) or "A or less and B or more" (when A > B). In addition, in the present invention, a combination of preferred modes is a more preferred mode.

[0029] [Deoxidizer Composition]

[0030] The deoxidizer composition of the present invention includes a mixed granulated product of a composition containing a water retention agent, a swelling agent, a metal salt, water, and iron. In the present invention, it is preferred that iron is dispersed throughout the mixed granulated product. The deoxidizer composition of the present invention may include only the aforementioned mixed granulated product, or may have a layer containing a porous carrier on the outside of the aforementioned mixed granulated product.

[0031] The inventors found that a deoxidizer composition obtained by mixing a water retention agent, a swelling agent, a metal salt, water, and iron together for granulation, which is a mixed granulated product of a composition containing a water retention agent, a swelling agent, a metal salt, water, and iron, has a fast oxygen absorption rate at the initial stage of the oxidation reaction of iron and can absorb the oxygen in the closed container in a short time.

[0032] In Patent Document 2 above, a powder body as a raw material for the α layer is produced by mixing a water retention agent and a swelling agent while adding an aqueous solution of a metal halide, and then iron powder is added to the powder body so that the iron powder adheres to the outside of the α layer, thereby producing an (α layer / β layer) powder body. Further, hydrophobic silica is added to the (α layer / β layer) powder body so that the hydrophobic silica adheres to the outside of the β layer, thereby producing an (α layer / β layer / γ layer) powder body. The oxygen scavenger composition described in Patent Document 2 has a practically sufficient oxygen absorption rate at the initial stage of the reaction, but the oxygen absorption rate at the initial stage of the oxygen scavenger composition of the present invention is further faster, and the oxygen in the closed container can be absorbed further in a short time.

[0033] The detailed mechanism for obtaining the effect of the present invention is not clear, but it is presumed as follows: By granulating by mixing a water retention agent, a swelling agent, a metal salt, water, and iron together, iron is dispersed as a whole in the granulated product, and iron exists close to water. Therefore, the amount of reaction at the initial stage of the oxidation reaction of iron is large. As a result, the oxygen absorption rate at the initial stage of the reaction is fast, and the oxygen in the closed container can be absorbed in a short time.

[0034] (Water retention agent)

[0035] The water retention agent contained in the oxygen scavenger composition of the present invention is a substance that infiltrates water inside and can retain water without oozing out.

[0036] As the water retention agent, there is no particular limitation as long as it can retain water, and porous substances and superabsorbent resins that can be generally obtained can be used. Examples of the porous substance include diatomaceous earth, zeolite, sepiolite, cristobalite, porous glass, silica, activated clay, acid clay, activated carbon, vermiculite, and wood powder. Examples of the superabsorbent resin include polyacrylate-based resins, polysulfonate-based resins, polyacrylamide-based resins, polyvinyl alcohol-based resins, starch-based resins, cellulose-based resins, and polyalginic acid-based resins. The water retention agent preferably contains at least one selected from the group consisting of diatomaceous earth, silica, and activated carbon. The above water retention agents can be used alone or in combination of two or more as needed. In addition, these water retention agents can also be easily obtained as commercial products.

[0037] Among the above water retention agents, activated carbon is particularly preferred because it has a function of promoting the oxidation reaction of iron in addition to the water retention function. There is no particular limitation on the type of activated carbon, and it can be any of wood, coconut shell, coal, etc.

[0038] There is no particular limitation on the properties of the water retention agent. From the perspective of the processability during the production of the deoxidizer, a powdery water retention agent with high fluidity is preferably used, and a water retention agent whose shape is close to spherical is more preferred. In addition, regarding the average particle size of the water retention agent, from the perspective of the processability during the production of the deoxidizer, it is preferably 10 μm or more and 1000 μm or less, more preferably 100 μm or more and 500 μm or less. If the particles of the water retention agent have a particle size within the above range, they can be used regardless of the difference between primary particles, aggregated particles, and granulated products. The water retention agent having a particle size within the above range can be used alone or a variety of those having different particle sizes can be mixed at any ratio.

[0039] There is no particular limitation on the content of the water retention agent in the deoxidizer composition. However, in 100% by mass of the deoxidizer composition, it is preferably 10% by mass or more and 40% by mass or less, more preferably 15% by mass or more and 30% by mass or less. In addition, relative to 100 parts by mass of water, it is preferably 20 parts by mass or more and 300 parts by mass or less, more preferably 50 parts by mass or more and 200 parts by mass or less. If the content of the water retention agent is within this range, the deoxidizer composition can sufficiently retain water and can increase the oxygen absorption amount per unit volume of the deoxidizer composition.

[0040] (Swelling agent)

[0041] The swelling agent contained in the deoxidizer composition of the present invention is a substance that swells through moisture and has a bonding function for maintaining the shape of the granulated product. The swelling agent is preferably used in a substantially dry state or in a semi-swollen or swollen state that has absorbed a small amount or a necessary amount of water.

[0042] As the swelling agent, if it is a generally known swelling agent, there is no particular limitation, and known swelling agents, binders, adhesives, and binders used in foods and the like can be used.

[0043] Examples of inorganic swelling agents include clay minerals such as sodium bentonite, calcium bentonite, and sodium montmorillonite. Examples of organic swelling agents include organic bentonite; 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. The above swelling agents can be used alone or two or more of them can be combined as needed. In addition, these swelling agents can also be easily obtained as commercial products.

[0044] Clay minerals are preferred because they are inexpensive and have excellent properties. Clay minerals are also known as inorganic soaps and have the function of a lubricant. In addition, it is known that clay minerals swollen by water exhibit high thixotropy and also exhibit adhesiveness, and thus are preferred. In addition, cellulose-based semi-synthetic products exhibit excellent swelling properties and are preferred. Among them, bentonite such as calcium bentonite and sodium bentonite, and carboxymethyl cellulose, sodium carboxymethyl cellulose, calcium carboxymethyl cellulose, etc. are preferred because they are inexpensive and have strong adhesive force. The swelling agent preferably contains at least one selected from the group consisting of calcium carboxymethyl cellulose, sodium carboxymethyl cellulose, calcium bentonite, and sodium bentonite.

[0045] Regarding the average particle size of the swelling agent, from the viewpoints of suppressing the generation of dust and the bonding function, it is preferably 0.001 μm or more and 10 μm or less, more preferably 0.01 μm or more and 1.0 μm or less.

[0046] There is no particular limitation on the content of the swelling agent in the deoxidizer composition, but in 100% by mass of the deoxidizer composition, it is preferably 0.1% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 15% by mass or less. In addition, relative to 100 parts by mass of iron, it is preferably 1 part by mass or more and 15 parts by mass or less, more preferably 3 parts by mass or more and 10 parts by mass or less. If the content of the swelling agent is within this range, it is easy to maintain the shape of the deoxidizer composition, and the ratio of the water retention agent will not be too small, and the water supply amount to iron will not decrease, and there is a tendency for the oxygen absorption amount to further increase.

[0047] (Metal salt)

[0048] The metal salt contained in the deoxidizer composition of the present invention is a substance that catalytically acts on the oxidation reaction of iron and improves the activity of iron. In addition, the metal salt plays a role in preventing the evaporation of the water contained in the deoxidizer composition and the loss of the deoxidizer composition.

[0049] There is no particular limitation on the metal salt, but a metal halide is preferred. As the metal halide, if it is a commonly known one, it can be used without particular limitation.

[0050] As the metal in the metal halide, there is no particular limitation, and examples thereof include at least one selected from the group consisting of alkali metals, alkaline earth metals, copper, zinc, aluminum, tin, iron, cobalt, and nickel. Among them, at least one selected from the group consisting of lithium, potassium, sodium, magnesium, calcium, barium, and iron is more preferred. In addition, as the halide in the metal halide, there is no particular limitation, and examples thereof include chlorides, bromides, and iodides.

[0051] As the metal halide, from the viewpoints of handleability, safety, etc., calcium chloride, sodium chloride, calcium bromide, sodium bromide, calcium iodide, and sodium iodide are preferred, and calcium chloride and sodium chloride are more preferred.

[0052] The metal salt can be used alone or in combination of two or more as needed. In addition, these metal salts can also be easily obtained as commercially available products.

[0053] When the metal salt is formed into a raw material in the form of an aqueous solution, the concentration of the salt is preferably 5% by mass or more and 30% by mass or less, more preferably 10% by mass or more and 20% by mass or less. When the salt concentration is 5% by mass or more, the effect of inhibiting the oxidation of catalytic iron is reduced. In addition, when the salt concentration is 30% by mass or less, the reduction of the vapor pressure of water can be inhibited. The reduction of the oxygen absorption amount due to insufficient supply of water to iron can be inhibited.

[0054] There is no particular limitation on the content of the metal salt in the deoxidizer composition, but in 100% by mass of the deoxidizer composition, it is preferably 0.5% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass or less. In addition, relative to 100 parts by mass of iron, it is preferably 0.5 part by mass or more and 20 parts by mass or less, more preferably 2 parts by mass or more and 10 parts by mass or less.

[0055] (Water)

[0056] From the viewpoint of the oxygen absorption performance of the iron-based deoxidizer, the deoxidizer composition of the present invention contains water. There is no particular limitation on the content of water in the deoxidizer composition, but in 100% by mass of the deoxidizer composition, it is preferably 10% by mass or more and 40% by mass or less, more preferably 15% by mass or more and 30% by mass or less. In addition, from the viewpoint of the oxygen absorption performance, relative to 100 parts by mass of iron, it is preferably 20 parts by mass or more and 50 parts by mass or less, more preferably 25 parts by mass or more and 40 parts by mass or less.

[0057] (Iron)

[0058] There is no particular limitation on the shape of the iron contained in the deoxidizer composition of the present invention, but from the viewpoints of oxygen absorption performance, ease of acquisition, and ease of handling, iron powder is preferred. For iron powder, there is no particular limitation if the surface of the iron is exposed, and reduced iron powder, electrolytic iron powder, spray iron powder, etc. can be suitably used. In addition, crushed products and cuttings of cast iron, etc. can also be used.

[0059] The iron powder can be used alone or in combination of two or more as needed. In addition, these iron powders can also be easily obtained as commercially available products.

[0060] In addition, iron powder covered with a metal halide can also be used. The iron powder covered with a metal halide can be manufactured by mixing the iron powder and an aqueous solution of the metal halide and then drying to remove water. The metal halide covering the iron powder can cover the aforementioned metal salt.

[0061] Regarding the average particle size of iron powder, from the viewpoint of good contact with oxygen, it is preferably 1 mm or less, more preferably 500 μm or less, and still more preferably 200 μm or less. From the viewpoint of suppressing the generation of dust, it is preferably 1 μm or more, more preferably 10 μm or more, and still more preferably 20 μm or more. It should be noted that the particle size referred to herein is the particle size measured by the weight fraction based on the sieve pore size after vibrating for 5 minutes using a standard sieve according to ISO3310-1:2000 (equivalent to JIS Z8801-1:2006).

[0062] In addition, regarding the specific surface area of iron powder, from the viewpoint of oxygen absorption capacity, it is preferably 0.05 m 2 / g or more, more preferably 0.1 m 2 / g or more. The specific surface area of iron powder can be measured by the BET multi-point method.

[0063] The deoxidizer composition of the present invention contains iron as the main agent. The content of iron in the deoxidizer composition is preferably 40% by mass or more and 90% by mass or less, more preferably 45% by mass or more and 80% by mass or less, still more preferably 50% by mass or more and 70% by mass or less, and still more preferably 50% by mass or more and 60% by mass or less, based on the deoxidizer composition.

[0064] <Mixed granulated product>

[0065] The deoxidizer composition of the present invention contains a mixed granulated product of a composition containing a water retention agent, a swelling agent, a metal salt, water, and iron. Herein, in the present invention, "granulation" refers to an operation of mixing single or raw material powders containing multiple components using an adhesive or the like, reducing the ratio of fine powder compared to the state of the raw material powders, and processing them into a granular form larger than the raw material powders. "Granulated product" refers to a powder body obtained by a granulation operation, in which the ratio of fine powder is reduced compared to the state of the raw material powders and is processed into a granular form larger than the raw material powders. The mixed granulated product in the present invention is not a compression molded product. That is, the granulated product contained in the deoxidizer composition of the present invention is not compression molded, and can be simply and inexpensively manufactured only by mixing.

[0066] In addition, the mixed granulate in the present invention preferably has iron dispersed throughout the mixed granulate. In the above-mentioned Patent Document 2, a water-absorbent resin and a swelling agent are mixed while adding an aqueous solution of a metal halide salt to produce a powder as a raw material for the α layer, and then iron powder is added to the powder so that the iron powder adheres to the outside of the α layer, thereby producing an (α layer / β layer) powder. Therefore, the iron powder is locally present near the outside of the powder. In contrast, as described later, the method for producing the deoxidizer composition of the present invention is a method including a step of granulating by mixing a water-absorbent resin, a swelling agent, a metal salt, water, and iron together. For the granulate obtained by this method, iron is dispersed throughout the granulate.

[0067] The content of the aforementioned mixed granulate in the deoxidizer composition of the present invention is preferably 90% by mass or more, more preferably 95% by mass or more, still more preferably 98% by mass or more, and still more preferably substantially 100%.

[0068] (Porous carrier)

[0069] The deoxidizer composition of the present invention may contain only the aforementioned mixed granulate, or may have a layer containing a porous carrier on the outside of the aforementioned mixed granulate.

[0070] The porous carrier that can be used in the present invention is not particularly limited as long as it is a carrier having a porous shape. Here, "porous" refers to a state in which there are many fine pores on the surface and inside that can be confirmed by an electron microscope. As the porous carrier, the porous substances used in the above-mentioned water-absorbent resin can be appropriately used, but silica-based materials are preferred. Silica-based materials refer to porous substances having silica (SiO2) as the main component. By using silica-based materials, the bulk density of the obtained powder increases and the oxygen absorption amount increases.

[0071] There is no particular limitation on the silica-based materials, and examples thereof include hydrophobic silica (surface-treated silica), wet silica, dry silica, silica gel, diatomaceous earth, acid clay, activated clay, pearlite, kaolin, talc, and bentonite. The above-mentioned porous carriers can be used alone or in combination of two or more as needed. In addition, these porous carriers can also be easily obtained as commercial products.

[0072] When the deoxidizer composition of the present invention contains a layer containing a porous carrier, the content of the porous carrier in the layer containing the porous carrier is preferably 30% by mass or more, more preferably 50% by mass or more, and still more preferably 80% by mass or more.

[0073] When the deoxidizer composition of the present invention has a layer containing a porous carrier, the content of the porous carrier in the deoxidizer composition is preferably 0.1% by mass or more and 5% by mass or less, more preferably 0.5% by mass or more and 3% by mass or less. When the content of the porous carrier is within this range, the bulk density of the deoxidizer composition tends to increase, the oxygen absorption amount further increases, and the fluidity of the deoxidizer composition is improved, so that the processability during the production of the deoxidizer package can be improved.

[0074] <Shape of the deoxidizer composition>

[0075] The shape of the deoxidizer composition of the present invention is not particularly limited, and examples thereof include a spherical shape, an elliptical shape, and a columnar shape. From the viewpoint of having a more excellent filling property and a further increase in bulk density, a spherical shape is preferred.

[0076] The average particle diameter of the deoxidizer composition of the present invention 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. When the average particle diameter is 0.3 mm or more, during filling and packaging, adhesion of the powder and granule contact part to the packaging machine due to static electricity etc. is suppressed. In addition, when the average particle diameter is 5.0 mm or less, there is a tendency to suppress an excessive gap between the powder and granules and a decrease in the oxygen absorption amount per unit volume. In order to obtain a deoxidizer composition having an average particle diameter within the above range, for example, sieving using sieves with pore diameters of 0.3 mm and 2 mm can be performed. The average particle diameter can be measured using, for example, a commercially available laser diffraction / scattering type particle size distribution measuring device ("LA-960" manufactured by Horiba, Ltd.).

[0077] The bulk density of the deoxidizer composition of the present invention is not particularly limited, and is preferably 1.0 g / mL or more, more preferably 1.3 g / mL or more, and further preferably 1.5 g / mL or more. When the bulk density is 1.0 g / mL or more, there is a tendency for the oxygen absorption amount per unit volume to be more excellent. In order to obtain a deoxidizer composition having a bulk density within the above range, for example, if a specific gravity classification machine ("HIGH SPEED ASPIRATOR" manufactured by Tokyo Flour Milling Machine Co., Ltd., etc.) is used to select the deoxidizer composition with the target bulk density. The bulk density can be measured according to JIS Z8901.

[0078] [Manufacturing method of the deoxidizer composition]

[0079] The method for manufacturing the deoxidizer composition of the present invention is not particularly limited, but preferably a method (the manufacturing method of the present invention) including a step of granulating by mixing a water retention agent, a swelling agent, a metal salt, water, and iron together. According to the manufacturing method of the present invention, by mixing the water retention agent, the swelling agent, the metal salt, water, and iron until they are uniformly dispersed to produce a mixed granulate, the deoxidizer composition can be effectively manufactured. In the above-mentioned Patent Document 2, a powder body as a raw material for the α layer is manufactured by mixing a water retention agent and a swelling agent while adding an aqueous solution of a metal halide salt, and then iron powder is added to the powder body so that the iron powder adheres to the outside of the α layer, thereby manufacturing a (α layer / β layer) powder body. Further, hydrophobic silica is added to the (α layer / β layer) powder body so that the hydrophobic silica adheres to the outside of the β layer, thereby manufacturing a (α layer / β layer / γ layer) powder body. That is, after manufacturing the powder body as a raw material for the α layer, a two-stage process of adhering iron powder to the outside of the α layer is required. In contrast, in the manufacturing method of the present invention, the deoxidizer composition can be manufactured by a one-stage process of granulating by mixing a water retention agent, a swelling agent, a metal salt, water, and iron together. Therefore, compared with the method of Patent Document 2, the deoxidizer composition can be effectively manufactured. In addition, the mixed granulate contained in the deoxidizer composition of the present invention is not subjected to pressure forming, and can be simply and inexpensively manufactured only by mixing.

[0080] There is no particular limitation on the mixing device. As a specific example, a Nauta mixer (manufactured by Hosokawa Micron Corporation), a conical mixer (manufactured by Ono Chemical Machinery Co., Ltd.), a vertical granulator (manufactured by POWREX CORP.), a high-speed mixer (manufactured by EARTH TECHNICA Co., Ltd.), and a granulator (manufactured by AKIRAKIKO co., ltd.) can be used.

[0081] In addition, as a method for manufacturing a deoxidizer composition having a layer containing a porous carrier, surface-treated silica (hydrophobic silica) can be added to the above-mentioned mixed granulate and mixed to form a layer containing a porous carrier on the outside of the above-mentioned mixed granulate, thereby manufacturing the deoxidizer composition.

[0082] Since iron, which is the main agent of the deoxidizer, reacts with oxygen, the reaction with oxygen proceeds slowly even in the absence of water, metal salts, etc. Therefore, the mixing is preferably carried out in an inert atmosphere (in the case of substantially forming a closed system, usually a reducing atmosphere in which there is no oxygen inside the system), and heat removal means are appropriately employed.

[0083] [Deoxidizer package]

[0084] The deoxidizer package of the present invention includes the above-mentioned deoxidizer composition and a breathable packaging material that houses the deoxidizer composition.

[0085] (Packaging material)

[0086] As the packaging material, examples include a packaging material formed by laminating two breathable packaging materials to form a bag shape; a packaging material formed by laminating one breathable packaging material and one non-breathable packaging material to form a bag shape; and a packaging material formed by bending one breathable packaging material and sealing the edge portions other than the bent portion to form a bag shape.

[0087] Here, when the breathable packaging material and the non-breathable packaging material are square-shaped, examples of the packaging material include a packaging material formed by overlapping two breathable packaging materials and heat-sealing the four sides to form a bag shape; a packaging material formed by overlapping one breathable packaging material and one non-breathable packaging material and heat-sealing the four sides to form a bag shape; and a packaging material formed by bending one breathable packaging material and heat-sealing three sides other than the bent portion to form a bag shape. Additionally, the packaging material can also be formed by making the breathable packaging material into a tubular shape and heat-sealing both ends and the middle portion of the tubular body to form a bag shape.

[0088] (Breathable packaging material)

[0089] As the breathable packaging material, a packaging material that selectively permeates oxygen and carbon dioxide is selected. Among them, a breathable packaging material having an air permeability resistance of 600 seconds or less, more preferably 90 seconds or less, obtained by the Gurley tester method is preferably used. Here, the air permeability resistance refers to the value measured by the method of JIS P8117 (1998). More specifically, it refers to the time required for 100 mL of air to pass through the breathable packaging material using a Gurley air permeability tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.).

[0090] As the above-mentioned breathable packaging material, in addition to paper and non-woven fabric, a breathable packaging material obtained by imparting air permeability to a plastic film is also used. As the plastic film, for example, films such as polyethylene terephthalate, polyamide, polypropylene, and polycarbonate, and laminated films formed by laminating and bonding films such as polyethylene, ionomer, polybutadiene, ethylene acrylic copolymer, ethylene methacrylic copolymer, or ethylene vinyl acetate copolymer as the sealing layer can be used. Additionally, their laminates can also be used as the breathable packaging material.

[0091] As the method for imparting air permeability, in addition to the perforation process using a cold needle or a hot needle, various methods can be adopted. When air permeability is imparted by the perforation process, the air permeability can be freely adjusted by the diameter, number, and material of the perforated holes.

[0092] In addition, the thickness of the laminated film is preferably 50 to 300 μm, particularly preferably 60 to 250 μm. At this time, compared with the case where the thickness is outside the above range, the strength can be maintained, and a packaging material excellent in heat sealability and packaging suitability can be formed.

[0093] Examples

[0094] Hereinafter, the present embodiment will be described in detail using examples and comparative examples. However, the present embodiment can be appropriately changed as long as the effects of the present invention are exhibited. It should be noted that "parts" in the examples and comparative examples refer to parts by mass unless otherwise clearly stated.

[0095] (Average particle size of the deoxidizer composition)

[0096] The average particle size of the deoxidizer composition was measured by a laser diffraction / scattering particle size distribution analyzer ("LA-960" manufactured by Horiba, Ltd.).

[0097] (Bulk density of the deoxidizer composition)

[0098] The bulk density (unit: g / mL) of the deoxidizer composition was measured according to JIS Z8901.

[0099] (Oxygen absorption amount of the deoxidizer composition)

[0100] 1 g of the deoxidizer composition and 3000 mL of air were added to a gas-barrier bag made of a nylon / polyethylene laminated film (size: 250 mm × 400 mm) and sealed. After the gas-barrier bag was kept at 25°C for 4 hours and 72 hours, the oxygen concentration inside the gas-barrier bag was measured, and the oxygen absorption amount (unit: mL) was calculated. The obtained oxygen absorption amount was divided by the volume (unit: mL) of the deoxidizer composition to calculate the oxygen absorption amount per unit volume (unit: mL / mL).

[0101] Example 1

[0102] 1240 parts of diatomaceous earth (“CG-2U” manufactured by ISOLITE INSULATING PRODUCTS CO., LTD.), 1120 parts of activated carbon (“S-W50” manufactured by FUTAMURA CHEMICAL CO., LTD.), 225 parts of calcium bentonite (“Neokunibond” manufactured by KUNIMINE INDUSTRIES CO., LTD.), 20 parts of sodium carboxymethyl cellulose (“F350HC-4” manufactured by NIPPON PAPER Chemicals CO., LTD.), an aqueous sodium chloride solution prepared by dissolving 407 parts of sodium chloride in 2008 parts of water, and 6000 parts of iron powder (average particle size: 100 μm) were put into a high-speed mixer (“SPG20L” manufactured by EARTHTECHNICA Co., Ltd.) and mixed at 240 rpm for 3 minutes to obtain a mixed granulated product.

[0103] Furthermore, 110 parts of surface-treated silica (“SS-30P” manufactured by Tosoh Silica Corporation) was added and mixed at 240 rpm for 30 seconds to obtain a deoxidizer composition having a porous carrier layer formed on the outside of the mixed granulated product. The average particle size of the obtained deoxidizer composition was 0.9 mm.

[0104] Example 2

[0105] In Example 1, the mixed granulated product before adding the surface-treated silica was collected and used as the deoxidizer composition of Example 2.

[0106] Comparative Example 1

[0107] 1240 parts of diatomaceous earth (“CG-2U” manufactured by ISOLITE INSULATING PRODUCTS CO., LTD.), 1120 parts of activated carbon (“S-W50” manufactured by FUTAMURA CHEMICAL CO., LTD.), 225 parts of calcium bentonite (“Neokunibond” manufactured by KUNIMINE INDUSTRIES CO., LTD.), and 20 parts of sodium carboxymethyl cellulose (“F350HC-4” manufactured by NIPPON PAPER Chemicals CO., LTD.) were put into a high-speed mixer (“SPG20L” manufactured by EARTHTECHNICA Co., Ltd.) and mixed at 240 rpm for 30 seconds. Then, while mixing at 240 rpm, an aqueous sodium chloride solution prepared by dissolving 407 parts of sodium chloride in 2008 parts of water was added over 30 seconds, and further mixed for 60 seconds to obtain a powder particle as the raw material for the α layer.

[0108] Next, 6000 parts of iron powder (average particle size: 100 μm) were added and mixed at 240 rpm for 3 minutes, thereby obtaining a granular material (α-layer / β-layer) in which a β-layer was formed on the outside of the granular material as the raw material of the α-layer.

[0109] Furthermore, 110 parts of surface-treated silica (manufactured by Tosoh Silica Corporation, "SS-30P") were added and mixed at 240 rpm for 30 seconds, thereby obtaining a deoxidizer composition containing a granular material (α-layer / β-layer / γ-layer) in which a γ-layer was formed on the outside of the granular material (α-layer / β-layer). The average particle size of the obtained deoxidizer composition was 0.9 mm.

[0110] It should be noted that for the cross-section obtained by cutting the obtained deoxidizer composition with a cutter, a cross-sectional photograph was taken using a digital microscope (manufactured by KEYENCE CORPORATION, "VHX-2000"). As a result, it was confirmed that the granular material (α-layer / β-layer / γ-layer) had a structure in which the α-layer was located at the center, the β-layer was located outside the α-layer, and the γ-layer was located further outside the β-layer.

[0111] Comparative Example 2

[0112] In Comparative Example 1, the granular material (α-layer / β-layer) before adding the surface-treated silica was collected and used as the deoxidizer composition of Comparative Example 2.

[0113] The bulk density and oxygen absorption amount per unit volume of the obtained deoxidizer composition are shown in Table 1. In Table 1, "raw material addition method" indicates the addition method of raw materials other than the surface-treated silica, "mixed together" indicates that the raw materials other than the surface-treated silica are mixed together, and "α-layer / β-layer" indicates that after mixing the raw materials other than the surface-treated silica and iron powder to form a granular material as the raw material of the α-layer, iron powder is added to form a β-layer outside the α-layer.

[0114] [Table 1]

[0115] Table 1

[0116]

[0117] From the comparison between Example 1 and Comparative Example 1 and the comparison between Example 2 and Comparative Example 2, it can be seen that compared with the deoxidizer compositions of Comparative Examples 1 and 2 in which a β-layer is formed outside the α-layer, the deoxidizer compositions of Examples 1 and 2 in which the raw materials are mixed together have a significantly higher oxygen absorption amount after 4 hours and a faster oxygen absorption rate at the initial stage of the oxidation reaction of the iron powder. That is, the deoxidizer compositions of Examples 1 and 2 can absorb the oxygen in a closed container in a short time.

[0118] In addition, from the comparison between Example 1 and Comparative Example 1 and the comparison between Example 2 and Comparative Example 2, it can be seen that, compared with the manufacturing method of the comparative example which requires a two-stage process of adding iron powder after forming the powder particles as the raw material for the α layer and forming the β layer outside the α layer, according to the method of the example in which the raw materials other than surface-treated silica are mixed together, a deoxidant composition with substantially the same bulk density and oxygen absorption per unit volume after 72 hours can be effectively manufactured in one stage.

Claims

1. A deoxidizer composition comprising a mixed granulate of a composition containing a water retention agent, a swelling agent, a metal salt, water, and iron, wherein the iron is dispersed throughout the mixed granulate, and having a layer containing a porous carrier on the outer side of the mixed granulate, wherein the swelling agent contains at least one selected from the group consisting of calcium bentonite and sodium bentonite, A method for producing the deoxidizer composition includes a step of mixing the water retention agent, the swelling agent, the metal salt, water, and iron together for granulation.

2. The deoxidizer composition according to claim 1, wherein The average particle size is 0.3 mm or more and 5.0 mm or less.

3. The deoxidizer composition according to claim 1 or 2, wherein The water retention agent contains at least one selected from the group consisting of diatomaceous earth, silica, and activated carbon.

4. The deoxidizer composition according to claim 1 or 2, wherein The mixed granulate is not a compression molded product.

5. A method for producing a deoxidizer composition, which is a method for producing the deoxidizer composition according to any one of claims 1 to 4, including a step of mixing the water retention agent, the swelling agent, the metal salt, water, and iron together for granulation, and a step of adding surface-treated silica to the mixed granulate and mixing, and forming a layer containing a porous carrier on the outer side of the mixed granulate.

6. A deoxidizer package comprising the deoxidizer composition according to any one of claims 1 to 4 and a breathable packaging material for containing the deoxidizer composition.

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