Oxygen absorber package, method for confirming its presence, and oxygen absorber composition

Abstract

To provide: a deoxidizer package which cannot be detected by a metal detection machine but can be detected by an X-ray foreign object detection machine; an existence confirmation method of the same; and a deoxidizer composition.MEANS FOR SOLVING THE PROBLEM: A deoxidizer package includes a nonferrous oxygen absorbing matter, and at least one type of inorganic compound (A) selected from a group comprising a copper compound, a zinc compound, a strontium compound, a zirconium compound, a barium compound, a tungsten compound, and a bismuth compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an oxygen absorber package, a method for confirming the presence of the package, and an oxygen absorber composition. [Background technology]

[0002] A method using an oxygen absorber has been conventionally used as a preservation technique for medicines, foods, etc. In this method, the preserved item and the oxygen absorber are enclosed in a gas-barrier sealed container and then sealed, so that the oxygen in the sealed container is absorbed by the oxygen absorber, thereby maintaining the atmosphere in the sealed container substantially oxygen-free.

[0003] When storing items and oxygen absorbers are sealed in a package, the most common method of checking for foreign objects is to use a metal detector or X-ray foreign object detector. Metal detectors can detect the presence of metallic foreign objects such as iron and stainless steel, while X-ray foreign object detectors can also detect the presence of glass, plastic, and other foreign objects.

[0004] On the other hand, the presence of an oxygen scavenger in a sealed container is generally confirmed by visual inspection or by using a metal detector. However, inspection using a metal detector is only possible for oxygen absorbers whose main ingredient is iron, and inspection using a metal detector cannot be applied to oxygen absorbers whose main ingredient is a non-ferrous oxygen absorbing substance such as ascorbic acid or glycerin. Therefore, there is a problem in that inspection of oxygen absorbers whose main ingredient is a non-ferrous oxygen absorbing substance must be done visually.

[0005] Visual inspection requires a great deal of effort, and there are problems such as the inevitable oversight of inspections, and the impossibility of inspection when opaque packaging materials are used. As a method for solving these problems, Patent Document 1 proposes an oxygen absorber in which an oxygen absorber composition containing a reducing organic compound as a main component and stainless steel powder are filled into a breathable bag. Because the oxygen absorber in Patent Document 1 uses stainless steel powder, the presence of the oxygen absorber can be confirmed using a metal detector. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-212838 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the case of the oxygen absorber of Patent Document 1, the oxygen absorber can be detected by a metal detector, so if metal foreign matter such as iron or stainless steel, which is widely used in the production process of food, pharmaceuticals, etc., gets mixed into a sealed container, the metal detector cannot detect these foreign matter.

[0008] Therefore, the present invention aims to provide an oxygen absorber package, a method for confirming the presence of the oxygen absorber, and an oxygen absorber composition, which, when using an oxygen absorber whose main component is a non-ferrous oxygen-absorbing substance in applications where a metal detector is used to check for the presence of metal foreign bodies such as iron and stainless steel, make it possible to confirm the presence of the oxygen absorber using an X-ray foreign body detector when the preserved item and the oxygen absorber are sealed and packaged, and which also makes it possible to use a metal detector to check for foreign bodies. [Means for solving the problem]

[0009] After extensive research, the inventors focused on inspection using an X-ray foreign object detector as a new inspection method for confirming the presence of an oxygen absorber package, rather than relying on visual inspection or a metal detector. They discovered that the above-mentioned problem could be solved by obtaining an oxygen absorber package that cannot be detected by a metal detector but can be detected by an X-ray foreign object detector, and thus completed the present invention.

[0010] That is, the gist and configuration of the present invention are as follows. [1] An oxygen absorber package containing a non-iron oxygen absorbing substance and at least one inorganic compound (A) selected from the group consisting of copper compounds, zinc compounds, strontium compounds, zirconium compounds, barium compounds, tungsten compounds, and bismuth compounds. [2] A method for confirming the presence of an oxygen absorber package, in which an X-ray foreign object detector is used to confirm that the oxygen absorber package described in [1] above is enclosed in a product. [3] An oxygen scavenger composition comprising a non-iron oxygen absorbing substance and at least one inorganic compound (A) selected from the group consisting of copper compounds, zinc compounds, strontium compounds, zirconium compounds, barium compounds, tungsten compounds, and bismuth compounds. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an oxygen absorber package, a method for confirming the presence thereof, and an oxygen absorber composition that are not detectable by a metal detector but are detectable by an X-ray foreign body detector. With such an oxygen absorber package of the present invention, when a preserved item and the oxygen absorber package are enclosed and sealed, the presence of the oxygen absorber package in the sealed container can be confirmed by an X-ray foreign body detector, and foreign body confirmation by a metal detector can also be used in combination to check for metal foreign bodies in the sealed container. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is an X-ray photograph of the oxygen absorber package of Example 10 and a packaging bag containing polished rice when the bag was passed through an X-ray foreign body detector. DETAILED DESCRIPTION OF THE INVENTION

[0013] [Oxygen absorber packaging] The oxygen absorber package of the present invention contains a non-iron oxygen absorbing substance and at least one inorganic compound (A) selected from the group consisting of copper compounds, zinc compounds, strontium compounds, zirconium compounds, barium compounds, tungsten compounds, and bismuth compounds.

[0014] The oxygen absorber package of the present invention has the above-described structure, so that it cannot be detected by a metal detector but can be detected by an X-ray foreign body detector. The reason why the oxygen absorber package of the present invention exhibits the above-mentioned effects is believed to be as follows. The non-ferrous oxygen absorbing substance and the above-mentioned specified inorganic compound (A) contained in the oxygen absorber package of the present invention are both substances that cannot be detected by a metal detector. On the other hand, the above-mentioned specified inorganic compound (A) is a substance that has high detection sensitivity to an X-ray foreign body detector, and it is believed that by containing such inorganic compound (A), the oxygen absorber package of the present invention cannot be detected by a metal detector but can be detected by an X-ray foreign body detector.

[0015] The oxygen absorber package of the present invention can be detected by an X-ray foreign body detector, making it possible to easily and accurately confirm the presence or absence of an oxygen absorber by non-destructive testing using an X-ray foreign body detector. As a result, it is possible to prevent the oxygen absorber package from being left behind, which helps reduce product defects and also saves labor in the inspection process by automating manual visual inspection. Furthermore, the oxygen absorber package of the present invention can be used in combination with a metal detector to check for metal contamination in products. That is, since the oxygen absorber package of the present invention cannot be detected by a metal detector, it does not interfere with the metal detector-based inspection for contamination, and only foreign matter such as iron or stainless steel can be accurately detected, which is thought to improve the accuracy of foreign matter detection.

[0016] In this specification, the oxygen absorber package refers to a package containing a non-iron oxygen absorbing substance and at least one inorganic compound (A) selected from the group consisting of copper compounds, zinc compounds, strontium compounds, zirconium compounds, barium compounds, tungsten compounds, and bismuth compounds, packaged in a packaging material. Each component will be described below.

[0017] <Non-ferrous oxygen absorbing substances> The non-ferrous oxygen absorbing substance used in the present invention is a non-ferrous substance that absorbs oxygen and is not limited in any way as long as it is a substance that cannot be detected by a metal detector, but examples include ascorbic acids such as ascorbic acid, ascorbate, erythorbic acid (isoascorbic acid), and erythorbate; polyhydric alcohols such as glycerin, ethylene glycol, propylene glycol, and glyceric acid; polyhydric phenols such as gallic acid and catechol; and compounds having unsaturated double bonds such as unsaturated hydrocarbons and hydrogenated rubber. These may be used alone or in combination of two or more.

[0018] Among these, the non-iron oxygen-absorbing substance is preferably at least one selected from the group consisting of ascorbic acid, ascorbic acid salts, erythorbic acid, erythorbic acid salts, glycerin, glyceric acid, gallic acid, and catechol. Ascorbic acids are particularly preferred because they generate carbon dioxide upon oxygen absorption, thereby keeping the volume of gas in the sealed container constant and preventing deformation of the sealed container, thereby enabling the shape of the preserved item to be maintained.

[0019] The content of the non-iron oxygen absorbing substance per oxygen absorber package is preferably 0.1 g or more, more preferably 1 g or more, from the viewpoint of obtaining a sufficient oxygen absorbing effect, and preferably 100 g or less, more preferably 50 g or less, from the viewpoint of economy. The content of the non-iron oxygen absorbing substance per oxygen absorber package is preferably 0.1 g to 100 g, more preferably 0.1 g to 50 g, and even more preferably 1 g to 50 g. Furthermore, the content of the non-iron oxygen absorbing substance in the contents of the oxygen absorber package (excluding the packaging material), from the viewpoint of oxygen absorption performance, is preferably 1 mass % to 70 mass %, more preferably 10 mass % to 50 mass %, and even more preferably 20 mass % to 50 mass %.

[0020] <Inorganic compounds (A)> The inorganic compound (A) used in the present invention is at least one selected from the group consisting of copper compounds, zinc compounds, strontium compounds, zirconium compounds, barium compounds, tungsten compounds, and bismuth compounds. Such inorganic compound (A) is a substance that cannot be detected by a metal detector but can be detected by an X-ray foreign body detector, and serves as a detection marker when confirming the presence or absence of an oxygen absorber package using an X-ray foreign body detector. From the viewpoints of enhancing the X-ray shielding effect and ease of availability, the inorganic compound (A) is preferably at least one selected from the group consisting of zinc compounds, strontium compounds, zirconium compounds, barium compounds, and bismuth compounds.

[0021] The inorganic compound (A) is not particularly limited as long as it is not detectable by a metal detector but is detectable by an X-ray foreign body detector, and examples thereof include oxides, carbonates, sulfates, hydroxides, and chlorides of various metals. From the viewpoints of enhancing the X-ray shielding effect and ease of availability, copper oxide (CuO), copper hydroxide (Cu(OH)2), zinc oxide (ZnO), strontium carbonate (SrCO3), strontium oxide (SrO), zirconium oxide (ZrO2), barium sulfate (BaSO4), tungsten boride (WB), and bismuth oxide (Bi2O3) are preferably used. Among these, barium sulfate and zinc oxide are more preferred.

[0022] The content of the inorganic compound (A) per oxygen absorber package is preferably 0.01 g or more, more preferably 0.02 g or more, even more preferably 0.05 g or more, still more preferably 0.10 g or more, and even more preferably 0.30 g or more from the viewpoint of enhancing the X-ray shielding effect and improving the detection accuracy by X-ray foreign body detection, and is preferably 5.0 g or less, more preferably 3.0 g or less, and even more preferably 1.0 g or less from the viewpoint of economy. The content of the inorganic compound (A) per oxygen absorber package is preferably 0.01 g or more and 5.0 g or less, more preferably 0.02 g or more and 5.0 g or less, still more preferably 0.02 g or more and 3.0 g or less, still more preferably 0.05 g or more and 3.0 g or less, still more preferably 0.10 g or more and 3.0 g or less, and even more preferably 0.30 g or more and 1.0 g or less. Furthermore, the content of the inorganic compound (A) in the contents of the oxygen absorber package (excluding the packaging material) is preferably 0.001% by mass or more and 50% by mass or less, more preferably 0.001% by mass or more and 40% by mass or less, even more preferably 0.001% by mass or more and 20% by mass or less, still more preferably 0.01% by mass or more and 10% by mass or less, and even more preferably 0.4% by mass or more and 10% by mass or less, from the viewpoint of the balance between the detection sensitivity in an X-ray foreign body detector and the oxygen absorption performance.

[0023] The shape of the inorganic compound (A) is not particularly limited, and examples thereof include powder, granules, particulates, etc. Among these, from the viewpoint of availability, at least one selected from the group consisting of powder and granules is preferred, and from the viewpoints of further enhancing the X-ray shielding effect and handling, granules are more preferred.

[0024] The inorganic compound (A) has an average particle size (D50) of preferably 1 μm or more, more preferably 50 μm or more, even more preferably 100 μm or more, still more preferably 300 μm or more, still more preferably 500 μm or more, and still more preferably 1000 μm or more from the viewpoint of enhancing the X-ray shielding effect and improving the detection accuracy of X-ray foreign matter detection, and from the viewpoint of handleability and packing property, it is preferably 5000 μm or less, more preferably 4000 μm or less, still more preferably 3000 μm or less, and still more preferably 2500 μm or less. The inorganic compound (A) has an average particle size (D50) of preferably 1 μm or more and 5000 μm or less, preferably 1 μm or more and 4000 μm or less, more preferably 100 μm or more and 3000 μm or less, and still more preferably 300 μm or more and 2500 μm or less. The average particle size (D50) of the inorganic compound (A) can be measured by the method described in the examples.

[0025] The loose bulk density of the inorganic compound (A) is preferably 0.5 g / mL or more, more preferably 1.0 g / mL or more, and even more preferably 1.2 g / mL or more from the viewpoint of increasing the X-ray shielding effect and improving the detection accuracy by X-ray foreign body detection, and from the viewpoint of ease of availability, it is preferably 10.0 g / mL or less, more preferably 5.0 g / mL or less, and even more preferably 3.5 g / mL or less. The loose bulk density of the inorganic compound (A) is preferably 0.5 g / mL or more and 10.0 g / mL or less, more preferably 1.0 g / mL or more and 5.0 g / mL or less, and even more preferably 1.2 g / mL or more and 3.5 g / mL or less. The loose bulk density of the inorganic compound (A) can be measured by the method described in the Examples.

[0026] The inorganic compound (A) may be present in any form as long as it is contained in the oxygen absorber package. Specifically, the inorganic compound (A) may be contained in the oxygen absorber composition described below, or may be present on the inside of the packaging material by coating, printing, or the like. From the viewpoint of production costs, it is preferable that the inorganic compound (A) is contained in the oxygen absorber composition.

[0027] <Other ingredients> In addition to the non-iron oxygen absorbing material and inorganic compound (A) described above, the oxygen absorber package of the present invention may contain other components to the extent that the effects of the present invention are not impaired, particularly to the extent that they are not detected by a metal detector. Specific examples of such components include alkaline substances, catalysts, carriers, swelling agents, heat generation inhibitors, water, and odor absorbents. It is particularly preferred that the package contain at least one selected from the group consisting of alkaline substances, catalysts, carriers, swelling agents, heat generation inhibitors, and water, and it is more preferred that the package contain an alkaline substance, catalyst, and carrier.

[0028] (alkaline substances) The alkaline substance is used for the purpose of rapidly promoting the oxidation reaction of the non-iron oxygen absorbing substance and controlling the reaction field in an alkaline region, and examples thereof include carbonates such as sodium carbonate, hydroxides such as sodium hydroxide, and salts of weak acids and strong bases. Among these, the alkaline substance is preferably at least one selected from the group consisting of alkali metal carbonates, alkali metal hydroxides, and alkaline earth metal hydroxides. Furthermore, from the viewpoint of the solubility in water when the alkaline substance forms a salt with a non-iron oxygen absorbing substance such as ascorbic acid, the alkaline substance is more preferably at least one selected from the group consisting of alkali metal carbonates and alkali metal hydroxides.

[0029] As the alkali metal carbonate, water-soluble alkali metal carbonates such as sodium carbonate, sodium hydrogen carbonate, and sodium carbonate hydrate are preferably used, and among these, sodium carbonate is particularly preferred. Examples of the alkali metal hydroxide include potassium hydroxide and sodium hydroxide, with sodium hydroxide being preferred. Examples of alkaline earth metal hydroxides include calcium hydroxide and magnesium hydroxide.

[0030] The content of the alkaline substance per oxygen absorber package is preferably equimolar to the molar amount of the non-iron oxygen absorbing substance from the viewpoint of neutralizing the hydrolysis product. The content of the alkaline substance in the contents of the oxygen absorber package (excluding the packaging material) is preferably 1% by mass or more and 15% by mass or less, more preferably 5% by mass or more and 10% by mass or less, and more preferably 8% by mass or more and 10% by mass or less.

[0031] (catalyst) The catalyst has the role of improving the amount and rate of oxygen absorption, and examples thereof include transition metal catalysts. The transition metal catalyst is preferably a transition metal salt. The transition metal salt is preferably at least one transition metal salt selected from the group consisting of Cu, Fe, Co, Ni, Cr, and Mn, and in consideration of oxygen absorption performance and safety, is more preferably at least one transition metal salt selected from the group consisting of Mn and Fe, and even more preferably Fe. As the transition metal salt, for example, inorganic salts such as sulfates, chlorides and nitrates, and organic salts such as fatty acid salts and acetylacetone metal salts can be suitably used, with sulfates being more preferred.

[0032] The catalyst content of the oxygen absorber package (excluding the packaging material) is preferably 0.5% by mass to 5% by mass, more preferably 1% by mass to 5% by mass, and more preferably 2% by mass to 4% by mass. Within the above ranges, a sufficient catalytic effect can be obtained and the catalyst will not be detected by a metal detector.

[0033] (Carrier) The carrier supports the non-iron oxygen absorbing material and the catalyst, and serves to improve the amount and rate of oxygen absorption, and examples thereof include activated carbon; calcium hydroxide; silicates such as calcium silicate, silica, and diatomaceous earth; zeolite, etc. Among these, activated carbon is preferred. The activated carbon not only functions as a carrier but also has the function of suppressing the generation of odor, and may be made from wood, coconut shell, coal, or the like.

[0034] The content of the carrier in the contents of the oxygen absorber package (excluding the packaging material) is preferably 1% by mass or more and 20% by mass or less, more preferably 4.5% by mass or more and 10% by mass or less, and more preferably 6% by mass or more and 10% by mass or less.

[0035] (swelling agent) The swelling agent is a substance that swells with water and has a caking function to maintain the shape of the granules. The swelling agent is preferably used in a substantially dry state or in a semi-swollen or swollen state after absorbing a small amount or a necessary amount of water.

[0036] The swelling agent is not particularly limited as long as it is a commonly known swelling agent, and known swelling agents, binding agents, adhesives, and binders used in foods and the like can be used. 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, lignosulfonic acid, and hydroxyethylated starch; and synthetic products such as water-insolubilized polyvinyl alcohol and polyvinyl methyl ether. The above-mentioned swelling agents can be used alone, or two or more can be used in combination as needed. Commercially available products may also be used as these swelling agents.

[0037] Among these, the swelling agent is preferably at least one selected from the group consisting of clay minerals and cellulose-based semi-synthetic products. Clay minerals are preferred because they are inexpensive and have excellent performance. Clay minerals are also known as inorganic soaps and function as lubricants. Clay minerals swollen with water are known to exhibit high thixotropy and are also preferred because they exhibit caking properties. Cellulose-based semi-synthetic products are also preferred because they exhibit excellent swelling properties. Among these clay minerals and cellulose-based semi-synthetic products, bentonites such as calcium bentonite and sodium bentonite, and cellulose-based semi-synthetic products such as carboxymethyl cellulose, sodium carboxymethyl cellulose, and calcium carboxymethyl cellulose are preferred because they are inexpensive and have strong caking power. From the above viewpoint, it is more preferable that the swelling agent contains at least one selected from the group consisting of carboxymethylcellulose calcium, carboxymethylcellulose sodium, calcium bentonite, and sodium bentonite.

[0038] The average particle size of the swelling agent 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, from the viewpoint of suppressing dust generation and of the caking function.

[0039] The content of the swelling agent is not particularly limited, but is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass, even more preferably 2.0 to 10% by mass, and even more preferably 2.5 to 5% by mass, of the contents of the oxygen absorber package (excluding the packaging material). Furthermore, the content is preferably 1 to 20 parts by mass, more preferably 5 to 15 parts by mass, per 100 parts by mass of the non-iron-based oxygen absorbing substance. If the content of the swelling agent is within this range, the shape of the contents of the oxygen absorber package (oxygen absorber composition) is easily maintained, and the proportion of the water retention agent is not too small, which prevents a decrease in the amount of moisture supplied to the non-iron-based oxygen absorbing substance and tends to increase the amount of oxygen absorbed.

[0040] (Fever suppressant) The heat generation inhibitor has the role of suppressing heat generation when the non-iron oxygen absorbing material absorbs oxygen, and is preferably crystalline thermoplastic resin particles. Normally, non-ferrous oxygen absorbing substances generate heat as they absorb oxygen, causing their temperature to rise, so depending on the product being stored, localized heating can cause problems such as deterioration, swelling, and deformation of the oxygen absorber package and packaging material.In addition, when large quantities are disposed of, there is a possibility that localized heating can occur due to heat accumulation. The crystalline thermoplastic resin particles have a crystalline portion and a melting point, and therefore when added to an oxygen absorber, the heat of fusion is locally absorbed during melting, thereby suppressing the generation of heat.

[0041] The thermoplastic resin forming the crystalline thermoplastic resin particles preferably has a heat of fusion per unit mass of 190 mJ / mg or more, and a melting point of 80°C or more and 150°C or less. The degree of crystallinity of the thermoplastic resin forming the crystalline thermoplastic resin particles is preferably 50% or more, more preferably 60% or more, and even more preferably 65% or more. The crystallinity of a thermoplastic resin is a value calculated by the density method.

[0042] Examples of the crystalline thermoplastic resin particles include polyolefin particles, polyester particles, and polyamide particles, with polyolefin particles and polyester particles being preferred, and polyolefin particles being more preferred. The polyolefin particles are preferably polyethylene particles or polypropylene particles, and more preferably polyethylene particles.

[0043] The crystallinity of the polyethylene constituting the polyethylene particles is preferably 50% or more, more preferably 60% or more, and even more preferably 65% or more. The crystallinity of polyethylene is a value calculated using the density method [JIS K6922-1:2018, and Polyethylene Resin Plastic Materials Lectures, Nikkan Kogyo Shimbun, 22 (1969)]. Polyethylene is a crystalline polymer, and since the crystalline portion is structurally more stable than the amorphous portion, the higher the crystallinity, the higher the density and therefore, it is preferable. The polyethylene used in the present invention may also be copolymerized with other monomers, such as propylene and 1-butene. The heat of fusion per unit mass of polyethylene is preferably 190 mJ / mg or more, and the melting point is preferably 80°C or more and 150°C or less.

[0044] The content of the crystalline thermoplastic resin particles is not particularly limited, but is preferably 1% by mass or more and 20% by mass or less, more preferably 2.5% by mass or more and 10% by mass or less, and even more preferably 3% by mass or more and 6% by mass or less, of the contents of the oxygen absorber package (excluding the packaging material).

[0045] The oxygen absorber package of the present invention may contain an iron-based oxygen absorbing substance such as iron powder, to the extent that it does not interfere with the detection of foreign matter such as iron or stainless steel, i.e., to the extent that it is not detected by a metal detector. The content of the iron-based oxygen absorbing substance per oxygen absorber package is preferably 0 g or more and 0.05 g or less, more preferably 0 g or more and 0.001 g or less, and even more preferably 0 g. In other words, it is preferable that the oxygen absorber package of the present invention does not substantially contain an iron-based oxygen absorbing substance.

[0046] <Packaging material> The oxygen absorber package of the present invention comprises a packaging material containing the above-mentioned non-iron oxygen absorbing substance and inorganic compound (A).

[0047] (packaging material) The packaging material is not particularly limited as long as it is a packaging material used for oxygen absorbers, but it is preferable to use a packaging material with high breathability in order to obtain sufficient oxygen absorption performance. Examples of such a packaging material include a bag made by bonding two sheets of breathable packaging material together, a bag made by bonding one sheet of breathable packaging material and one sheet of non-breathable packaging material together, and a bag made by folding one sheet of breathable packaging material and sealing the edges together except for the folded part.

[0048] Here, when the breathable packaging material and the non-breathable packaging material are rectangular, the packaging material may be formed by overlapping two sheets of breathable packaging material and heat-sealing the four sides to form a bag, by overlapping one sheet of breathable packaging material with one sheet of non-breathable packaging material and heat-sealing the four sides to form a bag, or by folding one sheet of breathable packaging material and heat-sealing three sides excluding the folded part to form a bag. The packaging material may also be formed by shaping the breathable packaging material into a cylindrical shape and heat-sealing both ends and the body of the cylindrical body to form a bag.

[0049] The shape of the packaging material is preferably one selected from the group consisting of a bag, a three-sided sealed shape, a four-sided sealed shape, a stick shape, a cylinder, and a box shape, and more preferably one selected from the group consisting of a stick shape, a cylinder, and a box shape. Furthermore, when the packaging material is sealed on three sides, its size is, for example, 10 mm to 120 mm in length and 10 mm to 120 mm in width.

[0050] (breathable packaging material) Breathable packaging materials are particularly suitable for oxygen and carbon dioxide permeability. Examples include nonwoven fabrics made from various fibers, such as Japanese paper, Western paper, and rayon paper; plastic films or perforated films; microporous films stretched after adding calcium carbonate; and laminates of two or more of these. Examples of plastic films include laminated films made by laminating and bonding a film of polyethylene terephthalate, polyamide, polypropylene, polycarbonate, or the like with a film of polyethylene, ionomer, polybutadiene, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, or ethylene-vinyl acetate copolymer, or the like, as a sealing layer. Preferred breathable packaging materials include polyethylene nonwoven fabrics and laminates of nonwoven fabrics and microporous films.

[0051] Among these, those having an air resistance measured by a Gurley tester of 600 seconds or less, more preferably 90 seconds or less, are preferably used. Here, air resistance refers to a value measured by the method of JIS P8117 (1998). More specifically, it refers to the time required for 100 mL of air to permeate the breathable packaging material using a Gurley densometer (manufactured by Toyo Seiki Seisakusho, Ltd.).

[0052] As a method for imparting breathability, various methods can be adopted, including perforation processing using a cold needle or a hot needle. When perforation processing is used to impart breathability, the breathability can be freely adjusted by the diameter, number, material, etc. of the holes to be perforated.

[0053] The thickness of the laminated film is preferably 50 μm or more and 300 μm or less, and particularly preferably 60 μm or more and 250 μm or less, in which case the film can be used as a packaging material that maintains strength and has excellent heat-sealing properties and packaging suitability, compared to thicknesses outside the above range.

[0054] (non-breathable packaging material) Examples of non-breathable packaging materials include packaging materials containing aluminum foil, etc. For example, when a breathable packaging material is used on one side of an oxygen absorber package and a non-breathable packaging material is used on the other side, oxygen can be absorbed from only one side.

[0055] The packaging material contains the above-mentioned non-iron oxygen absorbing substance and inorganic compound (A), as well as other components added as necessary, as contents, but the amount of these contents is not particularly limited and can be adjusted appropriately depending on the method of use of the oxygen absorber package, etc. For example, from the viewpoints of versatility, oxygen absorbing performance, and productivity of the oxygen absorber package, the amount of contents contained in one oxygen absorber package is preferably 0.1 g or more and 100 g or less, more preferably 0.5 g or more and 50 g or less, even more preferably 1 g or more and 20 g or less, and still more preferably 3 g or more and 10 g or less.

[0056] <Method of manufacturing oxygen absorber package> The method for producing the oxygen absorber package of the present invention is not particularly limited. The above-mentioned substances may be mixed together by a known method to form an oxygen absorber composition, which is then enclosed in a packaging material. Alternatively, the above-mentioned substances may be prepared separately and enclosed in a packaging material. For example, the oxygen absorber package may be produced by separately weighing and packaging the substances using a two-component filling packaging machine. Alternatively, the inorganic compound (A) may be present on the inside of the packaging material by coating, printing, or the like, and other substances may be enclosed in the packaging material.

[0057] When the inorganic compound (A) is in the form of powder or granules, from the viewpoint of obtaining a high X-ray shielding effect with a small amount added, it is preferable that the inorganic compound (A) is not mixed with other substances but is individually enclosed in a packaging material, and it is preferable that the inorganic compound (A) is concentrated in one place in the oxygen absorber package. Generally, the greater the density of the object, the greater the X-ray shielding effect. Therefore, when the inorganic compound (A) is in the form of powder or granules, the inorganic compound (A) is unevenly distributed in one place in the oxygen absorber package, compared to when the inorganic compound (A) is mixed with other materials and uniformly dispersed, and this creates a localized area where the inorganic compound (A) is present at a higher density, thereby increasing the X-ray shielding effect in this area and facilitating X-ray detection.

[0058] <Uses of oxygen absorber packaging> The oxygen absorber package of the present invention can be suitably used in applications where conventional oxygen absorbers have been used. For example, by enclosing a preserved item and the oxygen absorber package in a gas-barrier sealed container and sealing it, the oxygen in the sealed container can be absorbed by the oxygen absorber, thereby maintaining the atmosphere in the sealed container substantially oxygen-free. Examples of preserved items include medicines and food.

[0059] [How to check for the presence of oxygen absorber packaging] The oxygen absorber package of the present invention has the above-described configuration, which makes it detectable by an X-ray foreign body detector. Therefore, for products in which the oxygen absorber package is enclosed, an X-ray foreign body detector can be used to confirm that the oxygen absorber package is enclosed. According to this method for checking the presence of an oxygen absorber package, it is possible to check the presence or absence of an oxygen absorber package by non-destructive testing using an X-ray foreign object detector. As a result, it is possible to prevent the oxygen absorber package from being forgotten to be included in the product, which helps reduce product defects and also reduces the labor required for the inspection process by eliminating the need for manual visual inspection.

[0060] Specifically, the product containing the oxygen absorber package is a package in which the oxygen absorber package and an article to be preserved are enclosed in a packaging container. The preserved items are not particularly limited, but include, for example, medicines, food, etc. Furthermore, the food items include, for example, confectionery, rice products such as polished rice and mochi, meat, noodles, fish, etc. Typically, when checking for the presence of an oxygen absorber in a packaging container, the thicker the preserved item, the more easily the preserved item shields X-rays, making it difficult to detect the oxygen-absorbing package contained in the packaging container with X-rays. However, the oxygen-absorbing package of the present invention is easily detectable by X-rays, and can be sufficiently detected by an X-ray foreign object detector even if the preserved item is relatively thick. Therefore, this method is suitable for preserving thick preserved items in which it has been difficult to detect oxygen absorbers in the past, and is particularly suitable for preserving one or more types selected from the group consisting of rice and meat. The packaging container is not particularly limited, but is preferably a gas-barrier sealed container from the viewpoint of effectively maintaining the oxygen absorbing performance of the oxygen absorber package.

[0061] The X-ray foreign body detector used in the above confirmation inspection is not particularly limited, and any known inspection device can be used. The specific inspection method can be performed according to the method described in the Examples.

[0062] [Oxygen Absorber Composition] The oxygen scavenger composition of the present invention contains a non-iron oxygen absorbing substance and at least one inorganic compound (A) selected from the group consisting of copper compounds, zinc compounds, strontium compounds, zirconium compounds, barium compounds, tungsten compounds, and bismuth compounds. Such an oxygen absorber composition cannot be detected by a metal detector but can be detected by an X-ray foreign body detector, and therefore is suitable for use as the content of an oxygen absorber package.

[0063] The non-iron oxygen absorbing substance, the predetermined inorganic compound (A) and other components are as described above. In particular, from the viewpoint of the balance between the detection sensitivity in an X-ray foreign body detector and the oxygen absorption performance, the content of the inorganic compound (A) in the oxygen scavenger composition is preferably 0.001 mass% or more and 50 mass% or less, more preferably 0.001 mass% or more and 40 mass% or less, even more preferably 0.001 mass% or more and 20 mass% or less, still more preferably 0.01 mass% or more and 10 mass% or less, and even more preferably 0.4 mass% or more and 10 mass% or less.

[0064] The method for producing the oxygen absorber composition is not particularly limited and is substantially the same as the method for producing the oxygen absorber package described above. That is, the oxygen absorber composition may be any composition containing a non-iron oxygen absorbing substance and a predetermined inorganic compound (A), and may be produced by mixing the above-mentioned substances together by a known method, or may be produced by preparing the above-mentioned substances separately, sealing them individually in packaging materials, and finally mixing them in the packaging material to form the oxygen absorber composition.

[0065] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, but includes all aspects encompassed by the concept of the present invention and the scope of the claims, and can be modified in various ways within the scope of the present invention. [Example]

[0066] The present invention will now be described in more detail with reference to examples, but is not limited thereto. In addition, various measurements and evaluations in each Production Example, Example, and Reference Example were carried out as follows.

[0067] <Average particle size (D50)> The average particle size (D50) was measured using an image particle size distribution analyzer ("Camsizer X2" manufactured by Retsch Technology). For those samples whose average particle size (D50) could not be measured using the image particle size distribution analyzer, the samples were dispersed in water and the average primary particle size was measured by wet particle size distribution measurement using a laser diffraction / scattering particle size distribution analyzer (LA-960V2 series, manufactured by Horiba, Ltd.). The average particle size (D50) measured by this measurement is shown in Table 1 with parentheses next to it.

[0068] <Loose bulk density> The loose bulk density was measured using the powder property evaluation device "Powder Tester PT-X" according to the following procedure. (1) It has an opening, a depth of 4 cm, and a volume of 50 cm. 3 A cylindrical container is prepared, and the empty weight of the container is measured. (2) Gently sift the inorganic compound to be measured into the container until a uniform mound of inorganic compound is formed over the entire opening of the container and protruding from the container. (3) After leveling off the pile of inorganic compound, measure the total weight of the container and inorganic compound. (4) Calculate the loose bulk density using the following formula (I). Loose bulk density [g / cm 3 ] = {(total weight [g] - empty weight [g])} / container volume [cm 3 ]···(I)

[0069] <Metal detection test> Three of the obtained oxygen absorber packages were passed through a metal detector ("META-HAWK II" manufactured by System Square Co., Ltd.) to conduct a magnetic detection test for iron and stainless steel. The presence or absence of metal detection was judged according to the following evaluation criteria. (Evaluation criteria) None: All three oxygen absorber packages are not detected by the metal detector. Yes: One or more oxygen absorber packages were detected by the metal detector.

[0070] <X-ray foreign object detection test> Three obtained oxygen absorber packages were passed through an X-ray foreign object detector (X-ray inspection system manufactured by Anritsu Inficon Co., Ltd.) to conduct an X-ray foreign object detection test. The measurement conditions of the X-ray foreign object detector were set at a tube voltage of 60 kV and a tube current of 5.0 mA. Note that the possibility of X-ray detection was determined based on the following evaluation criteria according to the lowest value (minimum detection intensity) among the X-ray detection intensities of the three oxygen absorber packages. When it was determined that X-ray detection was possible according to the following evaluation criteria, it meant that the presence of the oxygen absorber package could be confirmed by the X-ray foreign object detector. (Evaluation criteria) AA: The minimum detection intensity of X-rays is 40 or more, and X-ray detection is easily possible. A: The minimum detection intensity of X-rays is 20 or more and less than 40, and X-ray detection is possible. B: The minimum detection intensity of X-rays is more than 0 and less than 20, and X-ray detection is difficult in some cases. C: The minimum detection intensity of X-rays is 0, and X-ray detection is impossible.

[0071] <Measurement of oxygen concentration (O2) and carbon dioxide concentration (CO2)> One obtained oxygen absorber package and 1000 mL of a mixed gas of 75 vol% nitrogen, 20 vol% oxygen, and 5 vol% carbon dioxide were placed in a gas barrier bag made of nylon / polyethylene laminated film and sealed. After storing at 25 °C for 48 hours, the oxygen concentration and carbon dioxide concentration inside the gas barrier bag were measured. The oxygen and carbon dioxide concentrations were measured using a gas analyzer (Check Mate 3 manufactured by mocon Dansensor). For the measurement of the oxygen concentration, the zirconia type oxygen concentration meter of the gas analyzer was used, and for the measurement of the carbon dioxide concentration, the infrared absorption type carbon dioxide concentration meter of the gas analyzer was used respectively.

[0072] (Production Example 1: Preparation of Base Composition 1) Base composition 1 was obtained by mixing 4.7 kg of sodium erythorbate, 2.1 kg of water, 1.0 kg of sodium carbonate, 1.0 kg of activated carbon ("Taiko S Type" manufactured by Futamura Chemical Co., Ltd.), 0.55 kg of powdered polyethylene ("Sunwax 171P" manufactured by Sanyo Chemical Industries, Ltd.), 0.40 kg of ferrous sulfate heptahydrate, 0.30 kg of bentonite ("Neokunibond" manufactured by Kunimine Industries Co., Ltd.), and 0.19 kg of carboxymethyl cellulose ("JP83" manufactured by Daicel Corporation).

[0073] (Production Example 2: Preparation of Base Composition 2) Base composition 2 was obtained by mixing 1.64 kg of glycerin, 0.3 kg of water, 0.12 kg of manganese chloride tetrahydrate, 0.012 kg of 5-methylresorcinol, and 8.3 kg of calcium hydroxide (granular slaked lime manufactured by Yabashi Industries Co., Ltd.).

[0074] (Examples 1 to 16) First, a three-side sealed bag (length 60 mm x width 65 mm) made of a breathable packaging material consisting of low-density polyethylene nonwoven fabric was prepared. Next, 5.0 g of the base composition 1 obtained in Production Example 1 and the inorganic compound (A) (marker substance) in the amount shown in Table 1 were added to the three-sided sealed bag, and the three-sided sealed bag was sealed to form an oxygen absorber package.

[0075] (Comparative Example 1) In Comparative Example 1, an oxygen absorber package was obtained in the same manner as in Example 1, except that the inorganic compound (A) was not used.

[0076] (Comparative Examples 2 to 6) In Comparative Examples 2 to 6, oxygen absorber packages were obtained in the same manner as in Example 1, except that inorganic compounds in the amounts shown in Table 1 were used instead of inorganic compound (A).

[0077] (Examples 17 to 20) In Examples 17 to 20, oxygen absorber packages were obtained in the same manner as in Example 1, except that 7.0 g of base composition 2 obtained in Production Example 2 was used instead of base composition 1, and the inorganic compound (A) was used in the amount shown in Table 1.

[0078] (Comparative Example 7) In Comparative Example 7, an oxygen absorber package was obtained in the same manner as in Comparative Example 1, except that 7.0 g of Base Composition 2 obtained in Production Example 2 was used instead of Base Composition 1.

[0079] [Table 1]

[0080] Details of the ingredients used in Table 1 are shown below. * Barium sulfate 1: "AD Barium Sulfate" manufactured by Nippon Chemical Industry Co., Ltd., barium sulfate (BaSO4) powder * Barium sulfate 2: "BAFELINE" manufactured by Sakai Chemical Industry Co., Ltd., barium sulfate (BaSO4) granules * Barium sulfate 3: Barium sulfate (BaSO4) granules Barium sulfate 3 was obtained by mixing and granulating 10 kg of barium sulfate ("AD Barium Sulfate" manufactured by Nippon Chemical Industry Co., Ltd.), 1.5 kg of water, and 0.0075 kg of carboxymethyl cellulose ("JP83" manufactured by Daicel Corporation), followed by drying. * Zinc oxide 1: Zinc oxide (ZnO) powder manufactured by Sakai Chemical Industry Co., Ltd. * Zinc oxide 2: Zinc oxide (ZnO) granules manufactured by Sakai Chemical Industry Co., Ltd. * Zirconium oxide: Fine granules of zirconium oxide (ZrO2) manufactured by Marumi Toryo Co., Ltd. * Bismuth oxide: bismuth oxide (Bi2O3) powder manufactured by Nippon Chemical Industry Co., Ltd. * Calcium hydroxide: Calcium hydroxide (Ca(OH)2) manufactured by Yabashi Industries Co., Ltd. * Silicon dioxide: Granules of silicon dioxide (SiO2) manufactured by Mikawa Silica Sand Co., Ltd. * Aluminum oxide: Fine granules of aluminum oxide (Al2O3) manufactured by Axens Canada Specialty Aluminas Inc. * Titanium oxide: Titanium oxide (TiO2) granules manufactured by Sakai Chemical Industry Co., Ltd. * Iron sand: Granules of iron oxide (Fe3O4) manufactured by Tohto Kosan Co., Ltd.

[0081] As shown in Table 1, it was confirmed that oxygen absorber packages containing a non-iron oxygen absorbing substance and a specified inorganic compound (A) could not be detected by a metal detector but could be detected by an X-ray foreign object detector (Examples 1 to 20). In contrast, it was confirmed that the oxygen absorber package of Comparative Example 1, which does not contain inorganic compound (A), and the oxygen absorber package of Comparative Example 2, which contains calcium hydroxide instead of inorganic compound (A), were not detected by either a metal detector or an X-ray foreign object detector. Furthermore, the oxygen absorber package of Comparative Example 7, which does not contain inorganic compound (A), and the oxygen absorber packages of Comparative Examples 3 to 5, which contain one of silicon dioxide, aluminum oxide, and titanium oxide instead of inorganic compound (A), were not detected by a metal detector, and although an X-ray foreign object detector confirmed that they slightly blocked X-rays, the shielding strength was weak and not at a level that could be considered detectable. Furthermore, the oxygen absorber package of Comparative Example 6, which contained iron sand instead of inorganic compound (A), was detectable with an X-ray foreign object detector, but it was also confirmed to be detected with a metal detector.

[0082] Furthermore, it was confirmed that all of the oxygen absorber packages exhibited sufficient oxygen absorbing capacity, and that the addition of inorganic compound (A) had no effect on the oxygen absorbing capacity. Furthermore, the oxygen absorber package using the base composition 1 containing ascorbic acids also has the ability to generate carbon dioxide, but the amount of carbon dioxide generated was reduced in the oxygen absorber package to which calcium hydroxide was added (Comparative Example 2), confirming the effect of adding calcium hydroxide on the carbon dioxide generation ability. In contrast, the oxygen absorber packages to which inorganic compound (A) was added (Examples 1 to 16) generated sufficient carbon dioxide, confirming that the addition of inorganic compound (A) had no effect on the carbon dioxide generation ability.

[0083] As confirmed in the above examples, the oxygen absorber package of the present invention cannot be detected by a metal detector but can be detected by an X-ray foreign object detector. Therefore, even when the preserved item and the oxygen absorber package are sealed and packaged in a sealed container, it is possible to easily check the presence or absence of the oxygen absorber package in the sealed container using an X-ray foreign object detector. For example, Figure 1 shows an X-ray photograph of the oxygen absorber package of Example 10 and 2 kg of polished rice placed in a 2-liter packaging bag (material: polyethylene, 70 mm thick, 30 mm long x 20 mm wide) and passed through an X-ray foreign object detector. As shown in Figure 1, the oxygen absorber package of the present invention provides strong shielding against X-rays, so even if the item being stored is relatively thick polished rice, it appears as a shadow in the X-ray photograph (the area enclosed by a square in Figure 1). Therefore, by checking this shadow, the presence of the oxygen absorber package placed in the packaging bag can be easily confirmed. [Industrial Applicability]

[0084] The oxygen absorber package of the present invention cannot be detected by a metal detector but can be detected by an X-ray foreign object detector. Therefore, it can be used in conjunction with a metal detector to inspect for metal foreign objects, and the presence or absence of an oxygen absorber can be confirmed by non-destructive inspection using an X-ray foreign object detector. This helps reduce product defects by preventing forgetting to include an oxygen absorber, and also automates manual visual inspection, thereby reducing the labor required for the inspection process.

Claims

1. An oxygen absorber package comprising a non-iron oxygen absorbing substance and at least one inorganic compound (A) selected from the group consisting of copper compounds, zinc compounds, strontium compounds, zirconium compounds, barium compounds, tungsten compounds, and bismuth compounds, wherein the inorganic compound (A) has an average particle size (D50) of 1000 μm or more and 5000 μm or less.

2. 2. The oxygen absorber package according to claim 1, wherein the non-iron oxygen absorbing substance is at least one selected from the group consisting of ascorbic acid, ascorbate, erythorbic acid, erythorbate, glycerin, glyceric acid, gallic acid, and catechol.

3. 3. The oxygen absorber package according to claim 1, wherein the content of the inorganic compound (A) is 0.01 g or more and 5.0 g or less.

4. The oxygen absorber package according to any one of claims 1 to 3, wherein the inorganic compound (A) is in at least one form selected from the group consisting of powder and granules.

5. An oxygen absorber package according to any one of claims 1 to 4, wherein the inorganic compound (A) has an average particle size (D50) of 1000 μm or more and 3000 μm or less.

6. The oxygen absorber package according to any one of claims 1 to 5, wherein the inorganic compound (A) is at least one selected from the group consisting of zinc compounds, strontium compounds, zirconium compounds, barium compounds, and bismuth compounds.

7. The oxygen absorber package according to any one of claims 1 to 6, further comprising at least one selected from the group consisting of an alkaline substance, a catalyst, a carrier, a swelling agent, a heat-generating inhibitor, and water.

8. a packaging material containing the non-iron-based oxygen absorbing substance and the inorganic compound (A); The oxygen absorber package according to any one of claims 1 to 7, wherein the shape of the packaging material is one selected from the group consisting of a bag shape, a three-sided sealed shape, a four-sided sealed shape, a stick shape, a cylinder shape, and a box shape.

9. A method for confirming the presence of an oxygen absorber package, comprising the steps of: inspecting a product in which the oxygen absorber package according to any one of claims 1 to 8 is enclosed, using an X-ray foreign object detector, to confirm that the oxygen absorber package is enclosed.

10. An oxygen scavenger composition comprising a non-iron oxygen absorbing substance and at least one inorganic compound (A) selected from the group consisting of copper compounds, zinc compounds, strontium compounds, zirconium compounds, barium compounds, tungsten compounds, and bismuth compounds, wherein the inorganic compound (A) has an average particle size (D50) of 1000 μm or more and 5000 μm or less.

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