Oxygen absorbing agent and resin composition

Abstract

The purpose of the present invention is to develop: an oxygen absorbing agent that is colorless (white), odorless, does not react with a metal detector, exhibits transparency even when blended in a resin, and has oxygen absorption performance higher than or equal to that of iron powder; and a resin packaging material having oxygen absorption performance.　The present invention provides an oxygen absorbing agent containing, as an active ingredient, a magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution represented by formula (1) (Mg and / or Ca), (1): 1 - x(M)x(OH)2 - nZ(An-)z (in the formula, M represents at least one or more substances selected from divalent Fe, Mn, and Co, A represents at least one or more n-valent (where n is 0 or an integer of 1 to 4) organic acid ion moieties and / or organic ligands, and x and z are respectively in the following ranges: 0 < x < 0.3, preferably 0.01 ≤ x ≤ 0.2, and particularly preferably 0.02 ≤ x ≤ 0.1; and 0 ≤ z ≤ 0.1, preferably 0.001 ≤ z ≤ 0.05, and particularly preferably 0.002 ≤ z ≤ 0.02).

Description

Oxygen absorbers and resin compositions

[0001] The present invention relates to a novel inorganic oxygen absorbent and an oxygen-absorbing resin composition containing the same. More specifically, the present invention relates to an oxygen absorbent containing as an active ingredient a solid solution obtained by substituting and solid-solving divalent white magnesium and / or calcium hydroxide with at least one selected from divalent Fe, Mn, and Co, and an oxygen-absorbing resin composition containing the same.

[0002] Food, pharmaceuticals, cosmetics, electronic components, etc., deteriorate in quality due to oxidation by oxygen in the air. To counteract this, oxygen absorbers are sealed in the packaging. As oxygen absorbers, metal powder-based oxygen absorbers using metal powders such as Fe, Mn, and Co, especially iron powder, as the main reactant are generally used from the viewpoint of non-toxicity, cost, and oxygen absorption capacity.

[0003] (1) Metal powders, such as iron powder, which are the most representative oxygen absorbers, have low oxygen absorption capacity on their own and require moisture for oxygen absorption. Furthermore, to accelerate oxygen absorption, these metal powders are used in combination with alkali metal halides or alkaline earth metal halides, especially their salts, as activators. Such metal powder-based oxygen absorbers are used, for example, by being packaged together with the packaging material, such as a resin film, for products such as food. However, metal powder-based oxygen absorbers have problems such as reacting to metal detectors used for foreign object inspection, igniting when used in a microwave oven, and being mistaken for food and accidentally ingested. (Patent Document 1)

[0004] In addition to metal powders, inorganic oxygen absorbers include (2) sulfite-based oxygen scavengers such as sulfites, bisulfites, and dithionites, and (3) oxygen-deficient compounds such as cerium oxide and partially reduced titanium oxide. However, oxygen scavengers (2), like metal powders, require moisture and have problems such as their odor transferring to food and their toxicity. Oxygen-deficient compounds (3) are expensive and have problems such as strong discoloration, poor transparency, and low oxygen absorption capacity.

[0005] Examples of organic oxygen absorbers include (4) L-ascorbic acid, sorbic acid and their salts, as well as sugars such as glucose, reducing polyhydric alcohols such as catechol and pyrogallol, and unmodified polybutadiene and maleic anhydride-modified polybutadiene having aliphatic unsaturated bonds (Patent Document 2). Organic oxygen absorbers have inferior oxygen absorption capacity compared to iron powder-based oxygen absorbers, require the addition of water, alkali or transition metals, and often have lower heat resistance than the resin processing temperature, which can cause foaming when processed into resin films.

[0006] Although oxygen-absorbing resin compositions containing iron powder and the like are known, none are colorless and transparent. (Patent Document 3)

[0007] JP 4-90848 A JP 2018-021128 A JP 11-080555 A

[0008] The present invention aims to provide a novel oxygen absorber and a transparent oxygen-absorbing resin packaging that can reduce the oxygen concentration inside the packaging to a level comparable to iron powder-based oxygen absorbers, is colorless (white), odorless, does not react to metal detectors, can be used in microwave ovens, and remains colorless and transparent even when compounded with resin.

[0009] The present invention relates to the following formula (1) (Mg and / or Ca) 1－ｘ (M) ｘ (OH) 2－ｎＺ (A ｎ－ ) ｚ (1) (In the formula, M represents at least one selected from divalent Fe, Mn, and Co, and A ｎ－The present invention provides an oxygen absorber containing a magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution as an active ingredient, represented by the formula (1) above, where n represents an n-valent [n = 0 or an integer in the range of 1 to 4] organic acid ion moiety and / or organic ligand, and x and z are in the following ranges: 0 < x < 0.3, preferably 0.01 ≤ x ≤ 0.2, particularly preferably 0.02 ≤ x ≤ 0.1, 0 ≤ < z < 0.2, preferably 0.001 ≤ z ≤ 0.05, particularly preferably 0.002 ≤ z ≤ 0.02). In one embodiment, in formula (1), Mg and / or Ca is Mg, and the oxygen absorber may contain a magnesium hydroxide-based solid solution as an active ingredient. In one embodiment, M in formula (1) may be divalent Fe. In one embodiment, A in formula (1) may be at least one selected from lactic acid, glycolic acid, ethylenediamine, and triethanolamine. In one embodiment, the range of x in formula (1) may be in the range of 0.01 ≤ x ≤ 0.2. In one embodiment, the width of the primary particles of the solid solution may be 0.5 μm or more. In one embodiment, the width of the primary particles of the solid solution may be 1 μm or more. In one embodiment, the solid solution may be surface-treated with at least one surface treatment agent selected from the group consisting of higher fatty acids, anionic surfactants, silane-based, titanium-based and aluminum-based coupling agents, phosphate esters, esters of polyhydric alcohols and fatty acids, silicone oil, and water glass. In one embodiment, x and z may each be 0 < x < 0.3 and 0 ≤ z < 0.1. In one embodiment, x and z may each be 0 < x < 0.3 and 0.001 ≤ z ≤ 0.05. In one embodiment, x and z may each be 0 < x < 0.3 and 0.002 ≤ z ≤ 0.02. In other embodiments, x and z may each be 0.01 ≤ x ≤ 0.2 and 1, 0 ≤ z < 0.1. In other embodiments, x and z may each be 0.01 ≤ x ≤ 0.2 and 0.001 ≤ z ≤ 0.05.In other embodiments, x and z may each be 0.01 ≤ x ≤ 0.2 and 0.002 ≤ z ≤ 0.02. In yet another embodiment, x and z may each be 0.02 ≤ x ≤ 0.1 and 0 ≤ z < 0.1. In yet another embodiment, x and z may each be 0.02 ≤ x ≤ 0.1 and 0.001 ≤ z ≤ 0.05. In yet another embodiment, x and z may each be 0.02 ≤ x ≤ 0.1 and 0.002 ≤ z ≤ 0.02. The present invention also provides an oxygen-absorbing and / or gas-barrier resin composition containing 0.01 to 300 parts by weight of the oxygen absorbent per 100 parts by weight of resin. The present invention also provides a resin packaging or resin container containing at least a portion that contains the oxygen absorbent or is formed from the oxygen-absorbing and / or gas-barrier resin composition. Furthermore, the present invention provides a method for manufacturing a product under a non-oxidizing atmosphere that avoids contact with oxygen as much as possible, by: (1) preparing a mixed aqueous solution (A+B) of (A) a water-soluble metal salt of Mg and / or Ca or a hydroxide of Ca and (B) at least one water-soluble metal salt selected from divalent Fe, Mn and Co, or a mixed aqueous solution (A+B+C) to which (C) an organic acid or an alkali metal salt and / or ammonium salt of an organic acid and / or an organic ligand is added in an amount of 10 mol% or less relative to the total number of moles of divalent metals; (2) adding alkali to the mixed aqueous solution (A+B) or the mixed aqueous solution (A+B+C) under stirring to cause a coprecipitation reaction and obtain a coprecipitation product; and (3) hydrothermally treating the coprecipitation product at 100°C or higher to obtain a magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution. (4) A method for producing the oxygen absorber is also provided, which includes preparing the oxygen absorber using the magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution.Furthermore, the present invention provides a method for manufacturing a magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution, where the entire manufacturing process is carried out under a non-oxidizing atmosphere that avoids contact with oxygen as much as possible: (S1) (A) an aqueous dispersion of calcium hydroxide and / or magnesium hydroxide, and (B) an aqueous solution of at least one water-soluble metal salt selected from divalent Fe, Mn, and Co, where optionally, (C) an organic acid or an alkali metal salt and / or ammonium salt of an organic acid and / or an organic ligand may be added to the aqueous dispersion of (A) or the aqueous solution of (B) or both, in an amount of 10 mol% or less relative to the total number of moles of divalent metals; (S2) the aqueous dispersion of (A) and the aqueous solution of (B) are reacted by mixing under stirring to obtain a magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution, where optionally, the magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution produced by the above reaction may be further subjected to hydrothermal treatment at 100°C or higher. (S3) A method for producing an oxygen absorber is also provided, which includes preparing an oxygen absorber using the magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution. In one embodiment, in (3) or (S2), one or more of the following treatments may be further performed on the obtained magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution: filtration, washing, surface treatment, drying, grinding, and classification. In one embodiment, the temperature and time of the hydrothermal treatment may be 150°C to 250°C and 1 to 10 hours, respectively.

[0010] The inventors focused on the fact that divalent Fe, Mn, and Co hydroxides have weak coloration and are essential minerals. However, divalent Fe, Mn, and Co hydroxides have the problem of being extremely easily oxidized. A further problem is that dehydration decomposition begins at temperatures below approximately 200°C, causing foaming during the mixing and molding processes with resins, making them unsuitable for use in resins. In order to solve these problems, the inventors diligently developed new materials and discovered that all of these problems can be solved by solid-solving at least one of the divalent Fe, Mn, and Co hydroxides into Ca and / or Mg hydroxides, which have high whiteness and a high decomposition temperature.

[0011] The oxygen absorber of the present invention has the following characteristics: (A) Ca and Mg are essential minerals required in moderate amounts, and their hydroxides are highly safe substances approved as food additives. Divalent Fe, Mn, and Co are essential minerals required in trace amounts. Therefore, the solid solution of formula (1) can be composed only of essential minerals, making it highly safe and suitable for resin materials for food packaging. (B) Although the hydroxides of divalent Fe, Mn, and Co are colored, the solid solution of formula (1) is colorless or white to gray, and its whiteness is high in the region of low solid solubility. (C) The dehydration decomposition start temperature of the solid solution of formula (1) is approximately 250°C or higher, which prevents foaming during resin processing. (D) The performance of the solid solution of formula (1) as an oxygen absorber is superior to that of iron powder in both oxygen absorption rate and capacity. Furthermore, while iron powder requires the presence of both moisture and an oxidation accelerator such as sodium chloride to exhibit high oxygen absorption performance, the solid solution of formula (1) does not necessarily require an oxidation accelerator. The solid solution of formula (1) has higher oxygen absorption performance than iron powder even without the presence of moisture, an oxidation accelerator, etc.

[0012] The oxygen absorber of the present invention offers the following advantages: (1) The oxygen absorbent capacity of the present invention is superior to that of existing oxygen absorbers. (2) Using the oxygen absorber of the present invention, colorless and highly transparent resin packaging containers or bags can be manufactured. Therefore, the contents packaged in the packaging container or bag can be visually inspected. (3) With currently mainstream oxygen absorbers, it is necessary to fill and seal the oxygen absorber in highly breathable small bags and then pack these small bags together with food or other items in a container, which requires time and equipment. However, with the oxygen absorber of the present invention, this time and equipment can be eliminated. (4) The oxygen absorber of the present invention does not react to metal detectors used for foreign object inspection, thus improving packaging efficiency. (5) The oxygen absorber of the present invention can be used in microwave ovens.

[0013] Figure 1 is a graph showing the oxygen absorption rate in a glass container.

[0014] The crystal structure of the solid solution of formula (1) contained in the oxygen absorber of the present invention is hexagonal Cd(OH) ２It belongs to the type structure. The solid solution of formula (1) is a substitutional solid solution in which a portion of Mg and / or Ca is substituted with at least one selected from divalent Fe, Mn, and Co. The solid solution may also be a solid solution between Mg and Ca, that is, Ca may be substituted in the Mg lattice of the solid solution, or Mg may be substituted in the Ca lattice of the solid solution. Divalent M hydroxide alone is colored blue, brown, or pink, but the solid solution system oxygen absorber of formula (1) of the present invention is strongly white in the range of low solid solution amounts, and when the solid solution amount exceeds 10 mol%, the whiteness decreases and it turns gray.

[0015] As the divalent, easily oxidizable metal M that absorbs oxygen, any of Fe, Mn, or Co can be used. When M is Co, the solid solution tends to be slightly discolored a pale pink and is expensive. Therefore, Fe or Mn are preferred over Co as M. Furthermore, since Fe has a smaller ionic radius than Mn, its solid solution range is wider than Mn's, its thermal stability is higher than Mn's, and it is cheaper than Mn. Therefore, Fe is the most preferred as M.

[0016] The solid solution range x is 0 < x < 0.3, preferably 0.01 ≤ x ≤ 0.2, and particularly preferably 0.02 ≤ x ≤ 0.1. When the solid solution amount x exceeds 0.2, whiteness, oxidation resistance (storage stability), and heat resistance (thermal decomposition temperature) tend to decrease.

[0017] The solid solution of formula (1) contained in the oxygen absorber of the present invention also includes an OH-substituted solid solution in which a portion of the OH groups are replaced with an organic acid and / or an organic ligand. In the case of partial substitution of OH groups with an organic acid, the effect of reducing the thickness of the crystal is achieved. In the case of partial substitution of OH groups with an organic ligand, the width of the crystal can be increased, and conversely, the thickness can be reduced (a higher aspect ratio). An improvement in the aspect ratio has the effect of improving the gas barrier performance. That is, in formula (1), A means an organic acid (particularly an organic acid ion portion) and / or an organic ligand. n is an integer from 0 to 4 (0, 1, 2, 3, or 4), and for example n may be 0, 1, or 2, or for example 0 or 1.

[0018] The organic acid that forms the solid solution is 1-2 valent, preferably 1 valent. Preferred organic acids include, for example, carboxylic acids such as formic acid, acetic acid, propionic acid, and benzoic acid, and sulfonic acids such as glycolic acid, methanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. That is, in one embodiment of the present invention, the organic acid ion portion in the solid solution is, for example, 1-2 valent, preferably 1 valent. The organic acid ion portion may be, for example, a carboxylic acid ion portion and / or a sulfonic acid ion portion, and more particularly a 1- or 2-valent carboxylic acid ion portion and / or a 1- or 2-valent sulfonic acid ion portion, and more preferably a 1-valent carboxylic acid ion portion and / or a 1-valent sulfonic acid ion portion. The carboxylic acid may be one or more combinations selected from the group consisting of formic acid, acetic acid, propionic acid, and benzoic acid. The sulfonic acid may be one or more combinations selected from the group consisting of methanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid.

[0019] Preferred organic ligands include monovalent oxycarboxylic acids such as glycolic acid and lactic acid, and amines such as ethylenediamine and triethanolamine. That is, in one embodiment of the present invention, the organic ligand may be, for example, an oxycarboxylic acid and / or an amine, and in particular may be a monovalent oxycarboxylic acid and / or a monovalent amine. The oxycarboxylic acid may be glycolic acid and / or lactic acid. The amine may be ethylenediamine and / or triethanolamine.

[0020] The smaller the primary particles (crystallites, plate-like) of the oxygen absorber of the present invention (particularly the solid solution contained in the oxygen absorber), the faster the oxygen absorption rate, but the worse the storage stability, so a moderate size is preferable. The width of the primary particles is, for example, 0.1 μm to 10 μm, preferably 0.2 μm to 10 μm, and particularly preferably 0.5 μm to 5 μm. The thinner the primary particles, the better the transparency of the resin and the better the gas barrier properties, so the thickness is preferably 0.2 μm or less, and particularly preferably 0.1 μm or less. The less aggregation of secondary particles of the oxygen absorber of the present invention (particularly the solid solution contained in the oxygen absorber), the better the transparency of the resin, which is preferable. Therefore, the range of the average particle size of the secondary particles is, for example, 0.1 to 15 μm, preferably 0.2 to 10 μm, and particularly preferably 0.5 to 6 μm. In other words, in one embodiment of the present invention, the solid solution contained in the oxygen absorber may have the form of secondary particles formed by the aggregation of primary particles. The primary particles may preferably have the width and / or thickness as described above. The secondary particles may preferably have the average particle size as described above.

[0021] The oxygen absorber of the present invention (particularly the solid solution contained in the oxygen absorber) is an inorganic crystal and therefore does not allow gases such as oxygen to pass through. The larger the width of the primary particles, and the higher the aspect ratio (10 or more, preferably 20 or more, particularly preferably 50 or more), the greater the oxygen-containing gas permeability blocking function (gas barrier property) of the oxygen absorber of the present invention. Therefore, when the oxygen absorber of the present invention is kneaded into a resin and formed into a film, this resin film blocks not only oxygen but also H ２ It can have gas barrier properties against all gases containing oxygen. Therefore, the oxygen absorber of the present invention exhibits superior gas barrier properties compared to conventional oxygen absorbers due to the physical gas barrier properties resulting from the plate-like shape of the crystal and the chemical oxygen scavenging properties due to the divalent Fe and / or Mn contained in the plate-like crystal. In other words, in one embodiment of the present invention, the primary particles of the solid solution contained in the oxygen absorber may have an aspect ratio of, for example, 10 or more, preferably 20 or more, and particularly preferably 50 or more.

[0022] The resin containing the oxygen absorber of the present invention is transparent. In particular, when the solid solution contained in the oxygen absorber of the present invention is a magnesium hydroxide-based solid solution, it is especially preferable because the refractive index of the solid solution is closest to that of the resin.

[0023] (Manufacturing Method) The oxygen absorber of formula (1) of the present invention can be manufactured by a method similar to that of known methods (for example, the method described in Japanese Patent Application Publication No. 5-209084). The solid solution contained in the oxygen absorber can be manufactured by, for example, (1) preparing (or creating) a mixed aqueous solution of (A) a water-soluble Mg and / or Ca salt and (B) at least one water-soluble divalent salt selected from Fe, Mn and Co, or by further adding (C) an organic acid and / or organic ligand in an amount of less than 10 mol% per 1 mole of the total divalent metals of A and B to a mixed aqueous solution of (A) and (B), however, the organic acid may be an alkali metal salt of an organic acid or an organic acid salt such as ammonium, and (2) adding alkali to the mixed aqueous solution of (A) and (B) or the mixed aqueous solution of (A), (B), and (C) in (1) above to co-precipitate, and then appropriately selecting steps such as hydrothermal treatment, filtration, washing (washing with water, etc.), drying, grinding, and classification. In other words, in one embodiment, the manufacturing method of the present invention is carried out under non-oxidizing atmosphere conditions (for example, under a nitrogen atmosphere) that avoid contact with oxygen as much as possible throughout the entire manufacturing process, (1) preparing a mixed aqueous solution (A+B) of (A) a water-soluble metal salt of Mg and / or Ca and (B) at least one water-soluble metal salt selected from divalent Fe, Mn and Co, or a mixed aqueous solution (A+B+C) to which (C) an organic acid or an alkali metal salt and / or ammonium salt of an organic acid and / or an organic ligand is added in an amount of 10 mol% or less relative to the total number of moles of divalent metals, (2) adding alkali to the mixed aqueous solution (A+B) or the mixed aqueous solution (A+B+C) under stirring to cause a coprecipitation reaction and obtain a coprecipitation product, and (3) hydrothermally treating the coprecipitation product at 100°C or higher to obtain a magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution. (4) This may include preparing an oxygen absorber using the magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution. By carrying out these steps (1) to (4), the oxygen absorber of the present invention can be produced. In (3) above, the coprecipitation reaction product may be subjected to hydrothermal treatment at 100°C or higher, and thereafter, optionally, one or more of the following treatments may be carried out: filtration, washing, surface treatment, drying, grinding, and classification.These processes may be carried out in the order described herein, but may be carried out in other orders. Furthermore, the solid solution may be in powder form, but may also be in other forms. In another embodiment, the manufacturing method of the present invention is carried out under non-oxidizing atmosphere conditions that avoid contact with oxygen as much as possible throughout the entire manufacturing process: (S1) (A) an aqueous dispersion of calcium hydroxide and / or magnesium hydroxide, and (B) an aqueous solution of at least one water-soluble metal salt selected from divalent Fe, Mn and Co, where optionally, (C) an organic acid or an alkali metal salt and / or ammonium salt of an organic acid and / or an organic ligand may be added to the aqueous dispersion of (A) or the aqueous solution of (B) or both, in an amount of 10 mol% or less relative to the total number of moles of divalent metals; (S2) the aqueous dispersion of (A) and the aqueous solution of (B) are reacted by mixing under stirring to obtain a magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution; where optionally, the magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution produced by the above reaction may be further subjected to hydrothermal treatment at 100°C or higher. (S3) The method may include preparing an oxygen absorber using the magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution. In this manufacturing method, the calcium hydroxide and / or magnesium hydroxide in the aqueous dispersion (A) in step (S1) perform the roles of the water-soluble metal salt of Mg and / or Ca in step (1) and the alkali in step (2) in the above embodiment. The oxygen absorber of the present invention can also be manufactured by performing these steps (S1) to (S3). In step (S2), the magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution may be subjected to hydrothermal treatment at 100°C or higher. In addition, in step (S2) (or after the hydrothermal treatment if it is performed), one or more of the following treatments may be further performed: filtration, washing, surface treatment, drying, grinding, and classification. These treatments may be performed in the order described herein, but may be performed in other orders. Furthermore, the solid solution may be in the form of a powder, but it may also be in other forms.An oxygen absorbent having a desired shape and / or structure may be prepared using the obtained magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution. The preparation may be carried out using methods and / or materials known in the art and may be appropriately carried out by those skilled in the art.

[0024] The amount of alkali added in the coprecipitation reaction of the step (2) may be, for example, 0.5 equivalent or more, preferably 0.6 to 1.0 equivalent, particularly preferably 0.7 to 0.9 equivalent, based on the total equivalent of the divalent metal. The temperature in the coprecipitation reaction may be, for example, 0 to 100°C, preferably 10 to 40°C, particularly preferably 10 to 30°C. The temperature of the hydrothermal treatment in the step (3) and the step (S2) may be, for example, 100°C or higher, preferably 120°C to 250°C, particularly preferably 150°C to 200°C. The time of the hydrothermal treatment may be, for example, 1 hour or more, preferably 2 to 10 hours, particularly preferably 3 to 6 hours.

[0025] Specific examples of water-soluble divalent metal salts used in the production method of the present invention include halides such as magnesium chloride, magnesium bromide, ferrous chloride, manganese chloride, and cobalt chloride; nitrates such as magnesium nitrate, ferrous nitrate, manganese nitrate, and cobalt nitrate; sulfates such as magnesium sulfate, ferrous sulfate, manganese sulfate, and cobalt sulfate; organic acid salts such as magnesium acetate, magnesium propionate, ferrous acetate, manganese acetate, and cobalt acetate. In other words, water-soluble metal salts of Mg (or Mg sources) used to prepare a mixed aqueous solution (A + B) or a mixed aqueous solution (A + B + C) in step (1) of the production method include magnesium chloride, magnesium bromide, magnesium nitrate, magnesium sulfate, and magnesium acetate, and the water-soluble metal salt of Mg (Mg source) may be one or more combinations selected from this group of magnesium salts. Furthermore, examples of water-soluble metal salts of Ca (or Ca sources) used to prepare the mixed aqueous solution (A+B) or mixed aqueous solution (A+B+C) used in the above manufacturing method include calcium chloride, calcium nitrate, and calcium acetate. That is, the water-soluble metal salt of Ca (Ca source) may be one or more combinations selected from the group consisting of calcium chloride, calcium nitrate, calcium acetate, and calcium hydroxide. In one embodiment, the Ca source may be calcium hydroxide. Furthermore, examples of water-soluble metal salts of divalent Fe (or Fe sources) used to prepare the mixed aqueous solution (A+B) or mixed aqueous solution (A+B+C) in step (1) of the above manufacturing method, or to prepare the aqueous solution of (B) in step (S1) of the above manufacturing method include ferrous chloride, ferrous nitrate, ferrous sulfate, and ferrous acetate. In other words, the water-soluble metal salt of divalent Fe (or Fe source) may be one or more combinations selected from the group consisting of ferrous chloride, ferrous nitrate, ferrous sulfate, and ferrous acetate.Furthermore, examples of water-soluble metal salts of divalent Mn (or Mn sources) used to prepare a mixed aqueous solution (A+B) or a mixed aqueous solution (A+B+C) in step (1) of the manufacturing method, or to prepare an aqueous solution of (B) in step (S1) of the manufacturing method, include manganese chloride, manganese nitrate, manganese sulfate, and manganese acetate. That is, the water-soluble metal salts of divalent Mn (Mn sources) may be one or more combinations selected from the group consisting of manganese chloride, manganese nitrate, manganese sulfate, and manganese acetate. Furthermore, examples of water-soluble metal salts of divalent Co (or Co sources) used to prepare a mixed aqueous solution (A+B) or a mixed aqueous solution (A+B+C) in step (1) of the manufacturing method, or to prepare an aqueous solution of (B) in step (S1) of the manufacturing method, include cobalt chloride, cobalt nitrate, cobalt sulfate, and cobalt acetate. In other words, the water-soluble metal salt of divalent Co (Co source) may be one or more combinations selected from the group consisting of cobalt chloride, cobalt nitrate, cobalt sulfate, and cobalt acetate. The amount of these sources used in the production method of the present invention may be appropriately adjusted according to the composition of the solid solution to be produced.

[0026] Specific examples of alkali compounds include sodium hydroxide, potassium hydroxide, aqueous ammonia, and calcium hydroxide. In other words, the alkali used in the coprecipitation reaction in the above-mentioned manufacturing method may be one or more combinations selected from the group consisting of sodium hydroxide, potassium hydroxide, aqueous ammonia, and calcium hydroxide.

[0027] In the step (1) or step (S1) of the manufacturing method, specific compounds of the organic acid used as (C) include monocarboxylic acids such as formic acid, acetic acid, and propionic acid, and sulfonic acids such as methanesulfonic acid and benzenesulfonic acid. Further, salts of the organic acid (for example, alkali metal salts of the organic acid (particularly Li salt, Na salt, or K salt) and / or ammonium salts) may be used as (C). Also, in the step (1) or step (S1) of the manufacturing method, specific compounds of the organic ligand used as (C) include oxycarboxylic acids such as glycolic acid, lactic acid, and glyceric acid, amines such as ethylenediamine and triethanolamine, and polyhydric alcohols such as ethylene glycol and glycerin.

[0028] (Surface Treatment) The oxygen absorber of formula (1) of the present invention can be given various functions by surface treatment. For example, in order to improve compatibility with resins and acid resistance, (a) higher fatty acids such as lauric acid and stearic acid, (b) alkali metal salts of the above higher fatty acids, (c) anionic surfactants such as sodium dialkylsulfosucrate, alkyl ether sulfate, 2-ethylhexylalkyl sulfate sodium salt, sodium acylmethyltaurate, sodium alkylbenzenesulfonate, and oleoylsarcosine, and (d) acid form / or alkali metal salt / or ammonium compound of mono or diester of orthophosphate and stearyl alcohol. (a) phosphate esters such as phosphate salts, (e) silane coupling agents such as vinylethoxysilane and γ-aminopropyltrimethoxysilane, (f) titanate coupling agents such as isopropyltriisostearoyl titanate, (g) aluminum coupling agents such as acetalkoxyaluminum diisopropylate, (h) fatty acid esters of polyhydric alcohols such as sorbitan monostearate, and (i) alkali metal salts of polycarboxylic acids and polysulfonic acids such as sodium polyacrylate and sodium polystyrene sulfonate can be used. In other words, the oxygen absorber of the present invention (especially the solid solution contained in the oxygen absorber) may be surface-treated by any of the above (a) to (i). In one embodiment, the manufacturing method of the present invention includes surface-treating the obtained magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution by, for example, any of the above (a) to (i).

[0029] To enhance heat resistance, silica coating can be performed by chemical adsorption of water glass followed by acid addition; silica coating by hydrolysis of methyl silicate, ethyl silicate, etc.; or silicone coating with silicone oil. To enhance ultraviolet absorption and / or scattering, coating with fine particles such as titanium dioxide, zinc oxide, or cerium oxide can be used. In other words, the oxygen absorber of the present invention (particularly the solid solution contained in the oxygen absorber) may be coated. The coating may be the silica coating, silicone coating, or coating with fine particles described above. Furthermore, in one embodiment, the manufacturing method of the present invention includes coating the obtained magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution with the silica coating, silicone coating, or coating with fine particles described above. Such surface treatment may be performed in the manufacturing method of the present invention.

[0030] The surface treatment method is preferably carried out wet or dry. The wet method involves dispersing the oxygen absorber of the present invention in a solvent such as water or alcohol, and adding the surface treatment agent while stirring. The dry method involves adding the surface treatment agent to the powdered oxygen absorber of the present invention while stirring with a high-speed stirrer such as a Henschel mixer. The amount of surface treatment is appropriately selected and determined depending on the purpose, but generally, the preferred range is 0.5 to 10% by weight relative to the weight of the oxygen absorber of the present invention (especially the solid solution).

[0031] (Resin Composition) The oxygen-absorbing resin composition of the present invention is blended with 0.1 to 300 parts by weight, preferably 1 to 200 parts by weight, and particularly preferably 5 to 150 parts by weight of the oxygen absorber of the present invention per 100 parts by weight of resin. The optimal blending amount may vary depending on the purpose. For example, if the purpose is solely oxygen absorption, the amount of the oxygen absorber may be, for example, 1 to 50 parts by weight per 100 parts by weight of resin. If the purpose is a gas barrier, the amount of the oxygen absorber may be, for example, 50 to 200 parts by weight per 100 parts by weight of resin. That is, the present invention also provides a resin composition containing at least a resin and an oxygen absorber according to the present invention, and more particularly an oxygen-absorbing and / or gas-barrier resin composition. In one embodiment, the content ratio of the oxygen absorber in the resin composition may be 0.1 to 300 parts by weight, preferably 1 to 200 parts by weight, and particularly preferably 5 to 150 parts by weight per 100 parts by weight of resin. In a particular embodiment, the content of the oxygen absorber in the resin composition may be, for example, 1 to 50 parts by weight, preferably 3 to 40 parts by weight, per 100 parts by weight of the resin. In this embodiment, the resin composition exhibits an oxygen absorption effect. In another particular embodiment, the content of the oxygen absorber in the resin composition may be, for example, 50 to 200 parts by weight, preferably 70 to 150 parts by weight, per 100 parts by weight of the resin. In this embodiment, the resin composition exhibits an even better gas barrier effect in addition to the oxygen absorption effect.

[0032] (Processing Method) There are no special restrictions on the mixing and kneading method with the resin, other than taking care to avoid contact with the atmosphere as much as possible and to prevent oxidation; any method that allows for uniform mixing of the two is acceptable. For example, mixing and kneading can be done using a uniscrew or twin-screw extruder, open roll, Banbury mixer, etc. There are also no special restrictions on the molding method; any known molding means can be arbitrarily adopted depending on the type of resin and rubber, the type of molded product desired, etc. Examples of molding means include extrusion molding, cast molding, inflation extrusion molding, blow molding, melt spinning, injection molding, injection blow molding, co-extrusion blow molding, etc. It is also possible to uniscrew or biscrew stretch films, sheets, etc.

[0033] The films and sheets formed from the resin composition of the present invention include single-layer films and sheets and multi-layer films and sheets. These films and sheets can be used as various packaging materials, etc. The total thickness of the film may be, for example, 5 μm to 250 μm, more particularly 10 μm to 250 μm, and more particularly 20 μm to 200 μm. The total thickness of the sheet may be, for example, 250 μm or more, more particularly 250 μm to 5000 μm, more particularly 250 μm to 3000 μm, and even more particularly 250 μm to 2000 μm. Generally, in the case of a single layer, the oxygen absorbent of the present invention can be filled into the resin at a high concentration and used as a gas barrier layer. In the case of a multi-layer, the oxygen absorbent can be filled into the resin at a relatively low concentration and used as an oxygen absorption layer. For example, the present invention provides a five-layer laminate film consisting of an adhesive (sealant) layer made of polyolefin (polypropylene, polyethylene, etc.) on the inside of the oxygen-absorbing layer (intended for packaging food, etc.), a gas barrier layer on the outside made of EVOH (ethylene-vinyl alcohol copolymer), inorganic material (silica, alumina, aluminum, etc.) vapor-deposited resin film, MXD6, aluminum foil, etc., and an outer layer made of PET, nylon, etc. on the outermost layer. The multilayer structure has two or more layers with no upper limit, and may include a layer made of paper. The five-layer laminate film may have a layer structure of outer layer / adhesive layer / oxygen-absorbing layer / gas barrier layer / outer layer from the side where the packaged object is located. In other words, the present invention also provides a laminate (film or sheet) that includes at least one layer formed from the resin composition of the present invention. The number of layers constituting the laminate may be, for example, two or more, for example, two to ten layers, more particularly two to seven layers, and more particularly three to five layers. If the laminate consists of three layers, the layer configuration may be a first resin layer, an oxygen-absorbing layer, and a second resin layer. The resins constituting the first and second resin layers may be as described below. The oxygen-absorbing layer may be formed from an oxygen-absorbing material-containing resin composition according to the present invention, as described above.

[0034] (Types of resins) The resins used in the present invention mean resins and / or rubbers, and include (A) thermoplastic resins such as polyethylene, copolymers of ethylene and other α-olefins, copolymers of ethylene and vinyl alcohol, vinyl acetate, ethyl acrylate or methyl acrylate, polybutene-1, poly-4-methylpentene-1, polystyrene, copolymers of styrene and acrylonitrile, copolymers of ethylene and propylene diene rubber or butadiene, polyvinyl acetate, polyvinyl alcohol, polyacrylate, polymethacrylate, polyurethane, polyester, polyether, polyamide, ABS, polycarbonate, polyvinyl chloride, chlorinated polyethylene, chlorinated polypropylene, etc.; (B) thermosetting resins such as phenolic resins, melamine resins, epoxy resins, unsaturated polyester resins, alkyd resins, etc.; and (C) rubbers such as EPDM, SBR, NBR, butyl rubber, chloroprene rubber, isoprene rubber, chlorosulfonated polyethylene rubber, silicone rubber, fluororubber, chlorinated butyl rubber, epichlorohydrin rubber, chlorinated polyethylene rubber, etc. In other words, in one embodiment, the resin contained in the resin composition according to the present invention may be a thermoplastic resin, a thermosetting resin, or a rubber.

[0035] Preferred resins include thermoplastic resins such as polypropylene, polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyamide, polystyrene, and polyester. In other words, the resins included in the resin composition according to the present invention may be one or more combinations selected from the group consisting of these resins.

[0036] The resin used in the adhesive layer preferably contains a carboxylic acid-modified polyolefin. As the carboxylic acid-modified polyolefin, a modified polyolefin polymer containing carboxyl groups, obtained by chemically bonding an ethylenically unsaturated carboxylic acid, its ester, or its anhydride to an olefin polymer, is preferred. Linear low-density polyethylene and ethylene-vinyl acetate copolymers are particularly preferred as olefin polymers.

[0037] The resin composition of the present invention may contain, in addition to the oxygen absorber, other conventional additives such as antioxidants, ultraviolet absorbers, lubricants, crosslinking agents, light stabilizers, antistatic agents, and pigments, as well as reinforcing agents such as high-aspect-ratio magnesium hydroxide, selected and blended as appropriate. Regarding the amounts of these additives, the content of additives other than reinforcing agents is preferably, for example, 0.001 to 5 parts by weight per 100 parts by weight of resin. The content of the reinforcing agents is preferably, for example, 5 to 200 parts by weight per 100 parts by weight of resin. The oxygen absorber of the present invention may be contained in packaging or containers of various shapes. Furthermore, the resin composition containing the oxygen absorber of the present invention may form part or all of the packaging or container. That is, the present invention also provides packaging or containers (particularly resin-made methods or resin-made containers) that contain the oxygen absorber or are formed at least in part from the resin composition. For example, the oxygen absorber of the present invention may be placed in packaging or containers so as to be able to absorb oxygen in the packaging or container. For example, when sealing contents such as food inside a package or container, the oxygen absorber may be sealed inside the package or container together with the contents. Furthermore, the oxygen absorber-containing resin composition of the present invention may form part or all of the package or container. For example, a portion of the package may be formed from the oxygen absorber-containing resin composition, while other portions may be formed from other materials (e.g., resin). Alternatively, a portion of the container (e.g., the container body or lid) may be formed from the oxygen absorber-containing resin composition, while other portions of the container (e.g., the lid or container body) may be formed from other materials (e.g., resin). Such packages or containers can prevent oxidation of the contents contained within them. The packages or containers can also be made transparent or translucent so that the contents are visible. Furthermore, the packages or containers do not react to metal detectors and can even be used in microwave ovens.

[0038] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, (A) primary particle size, (B) average secondary particle size, and (C) oxygen absorption amount were measured by the method described below.

[0039] (A) Primary particle size: The powder, sieved through a 60-mesh sieve, is dispersed in water using ultrasound for 5 minutes. The maximum width and thickness of the primary particles are then measured for each of the five particles using a scanning electron microscope (SEM), and the arithmetic mean of the measured values ​​is taken as the maximum width and thickness of the primary particles.

[0040] (B) Average secondary particle size The sample dispersed in the same manner as in (A) is measured using a laser diffraction particle size analyzer (Horiba LA960), and the 50% cumulative secondary particle size is taken as the average secondary particle size.

[0041] (C) Oxygen absorption amount (deoxygenation rate) 880 mL of air (oxygen concentration 20.9%) and 3 g of oxygen absorbent (without water added) or 3 g of oxygen absorbent and 1 g of water (with water added) were placed in a glass bottle container, sealed with a lid equipped with an oxygen sensor, and the change in oxygen concentration in the air was measured at room temperature using a RIKENKEIKI oxygen monitor.

[0042] All water used was deionized water, boiled to remove dissolved oxygen, and used to dissolve the metal salts. 500 mL of a mixed aqueous solution of magnesium chloride and ferrous chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (Mg = 2.0 mol / L, Fe = 0.05 mol / L, 20°C) and 1.8 g of sodium lactate aqueous solution (manufactured by Musashino Chemical Laboratory, concentration: 50 wt%) were placed in a 1 L four-necked flask. After replacing the atmosphere (air) with nitrogen gas, 205 mL of sodium hydroxide aqueous solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (8 M / L, 20°C) was added under stirring and coprecipitation was performed.

[0043] The coprecipitation was transferred to a 1 L Hastelloy C autoclave, the atmosphere was replaced with nitrogen gas, and the mixture was hydrothermally treated at 200°C for 4 hours. After cooling to room temperature, it was filtered under reduced pressure in a nitrogen atmosphere, washed with water, and the resulting cake was placed in a vacuum dryer and dried at 120°C for 2 hours. The resulting dried product was white, and after sieving with a 60 mesh sieve, XRD and compositional analysis were performed.

[0044] XRD is slightly shifted to the low-angle side and shows only the same diffraction pattern as magnesium hydroxide, so this substance is a magnesium hydroxide-based solid solution. After sieving the powder, it was dissolved in hydrochloric acid, and Mg was determined by chelatometric titration, and divalent and trivalent iron were separated and quantified by spectrophotometry (Handbook of Analytical Chemistry, edited by the Chemical Society of Japan, Maruzen Publishing, page 185). As a result, the chemical composition is as follows. Lactic acid was quantified by spectrophotometry. Mg ０．９４ Fe(2+) ０．０６ (OH) １．９９ (C ３ H ５ O ３ ) ０．０１　 (Trivalent iron is almost 0%). The lateral width of the primary particles of this solid solution was 3.1 μm, the thickness was 21 nm, and the average secondary particle diameter was 2.6 μm. Using the sieved powder, an oxygen absorption test was conducted. As a result, the oxygen concentration after 24 hours was 12.8% without adding moisture and 5.0% with added moisture. When converted to the oxygen absorption amount per gram, they are 23 cc / g and 47 cc / g, respectively.

[0045] In Example 1, except that the concentration of ferrous chloride was changed to 0.25 mol / L, the amount of sodium hydroxide was changed to 225 mL, no aqueous sodium lactate solution was added, and the hydrothermal treatment temperature was changed to 150 °C, a dried product was obtained in the same manner as in Example 1. The dried product is almost white, and XRD shows the same tendency as in Example 1, so it is a magnesium hydroxide-based solid solution. The chemical composition of the magnesium hydroxide-based solid solution was determined by the method described in Example 1. The determined chemical composition is as follows. Mg ０．８８ Fe(2+) ０．１２ (OH) ２ (Trivalent iron is 0.1% of the total iron) The lateral width of the primary particles of the dried product was 1.2 μm, the thickness was 20 nm, and the average secondary particle diameter was 1.5 μm. As a result of conducting the oxygen absorption test in the presence of moisture, the oxygen concentration after 24 hours was 8.2%. When converted to per gram, it is 37 cc / g.

[0046] In Example 1, a dried product was obtained in the same manner as in Example 1, except that cobalt chloride was used instead of ferrous chloride, sodium lactate aqueous solution was not added, and the amount of sodium hydroxide was changed to 240 mL. The dried product was almost white, and the XRD showed the same trend as in Example 1, so it is a magnesium hydroxide-based solid solution. The chemical composition of the magnesium hydroxide-based solid solution was determined by the method described in Example 1. The determined chemical composition is as follows: Mg ０．９４ Co(2+) ０．０６ (OH) ２　 The primary particles of the dried material had a width of 3.7 μm, a thickness of 90 nm, and an average secondary particle diameter of 3.9 μm. An oxygen absorption test conducted in the presence of moisture revealed an oxygen concentration of 11.8% after 24 hours. This translates to 27 cc / g.

[0047] In Example 1, a dried product was obtained in the same manner as in Example 1, except that manganese nitrate (manufactured by Fujifilm Wako Pure Chemical Industries) was used instead of ferrous chloride. The dried product was almost white, and the XRD showed the same trend as in Example 1, indicating that it is a magnesium hydroxide-based solid solution. After dissolving the dried product in hydrochloric acid, Mg and Mn were quantified by chelation titration, and the chemical composition was determined as follows: Mg ０．９４ Mn ０．０６ (OH) ２ The primary particles of the dried material had a width of 2.5 μm, a thickness of 62 nm, and an average secondary particle diameter of 2.9 μm. An oxygen absorption test was conducted on the dried material in the presence of moisture, and the oxygen concentration after 24 hours was 11.2%. The oxygen absorption rate per gram was 45 cc / g.

[0048] 76 g of commercially available slaked lime was added to 600 mL of deionized water and dispersed with a stirrer. Then, 100 mL of an aqueous solution of ferrous chloride (1.0 mol / L) was added under stirring and the reaction was carried out. The resulting reaction slurry was subjected to vacuum filtration, washing with water, and vacuum drying in the same manner as in Example 1 to obtain a dried product. The dried product was a slightly grayish white, and although the XRD was slightly shifted to the high-angle side, it showed the same diffraction pattern as calcium hydroxide, thus indicating that it is the same Cd(OH) as magnesium hydroxide. ２This is a solid solution having a specific structure in which some of the Ca in calcium hydroxide is replaced by divalent iron. The composition of this solid solution was chemically analyzed using the method described in Example 1. The composition determined by this analysis is as follows: Ca ０．９ Fe ０．１ (OH) ２ (Trivalent iron content: 0.2%) The primary particles of this solid solution had a width of 0.3 μm, a thickness of 120 nm, and an average secondary particle diameter of 1.2 μm. After sieving, the powder was subjected to an oxygen absorption test with added water, and the oxygen concentration after 24 hours was 15.0%. Converted to an oxygen absorption rate per gram, the oxygen absorption rate was 17 cc / g.

[0049] [Comparative Example 1] An oxygen absorption test was conducted using iron powder (Fujifilm Wako Pure Chemical Industries). The results showed that the oxygen concentration after 24 hours was 17.1% for the powder alone and 11.9% when water was added. The oxygen absorption per gram was 11 cc / g and 26 cc / g, respectively.

[0050] [Comparative Example 2] The procedure was the same as in Example 1, except that the concentration of ferrous chloride was changed to 0.6 mol / L and the hydrothermal treatment temperature was changed to 150°C. The dried product was light brown, and the XRD showed the same diffraction pattern as in Example 1, with the strongest peak observed at approximately 11°C, which is thought to be Mg-Fe(3+) type hydrotalcite. Therefore, this dried product is a mixture of a divalent iron solid solution magnesium hydroxide-based solid solution and Mg-Fe(3+) type hydrotalcite. When this dried powder was subjected to an oxygen absorption test with the addition of water, the oxygen concentration after 24 hours was 16.4%. Therefore, the oxygen absorption amount per gram is 13 cc / g.

[0051] (Oxygen absorber-containing resin) The undried cake obtained by the method of Example 1 was placed in a 1 L four-necked flask with about 500 mL of water, the air was replaced with nitrogen gas, and the mixture was dispersed with a stirrer, then the temperature was raised to about 80°C. 100 mL of an aqueous solution at about 80°C containing 1.5 g of sodium stearate was added under stirring, and the mixture was stirred for about 10 minutes to perform surface treatment. After this, the mixture was filtered under a nitrogen stream, washed with water, and then vacuum-dried at 120°C for 1 hour to obtain the dried product.

[0052] After sieving the dried material through a 60-mesh sieve, 8 g of the sieved dried material was mixed with 72 g of polypropylene (Prime Polymer, J707EG) and 0.15 g of antioxidant (IRGANOX 1010). The mixture was then melt-kneaded at 170°C for 10 minutes using a Brabender mixer. The resulting molten material was then pressed into a press mold at a pressure of 50 kg / cm². ２ A resin sheet measuring 1 mm x 140 mm x 160 mm was created by pressure molding at 180°C for 5 minutes. This molded sheet was cut into approximately 5 mm x 5 mm x 1 mm pieces with scissors, and 30 g of these pieces (containing 3 g of oxygen absorbent) were used to conduct an oxygen absorption test. The results of the test showed that the oxygen concentration after 24 hours was 13.0% without water addition and 5.0% with water addition. The oxygen absorption per gram was 23 mL / g and 47 mL / g, respectively.

[0053] Figure 1 shows the results of measuring the change in oxygen absorption over time for the oxygen absorbent powder of the present invention (Example 1), the oxygen absorbent-containing resin composition of the present invention (Example 6), and iron powder (manufactured by Fujifilm Wako Pure Chemical Industries), which is a representative of conventional oxygen absorbers. From Figure 1, it can be seen that the oxygen absorbent of the present invention is superior to iron powder, a representative of conventional oxygen absorbers, even when blended with resin.

[0054] The surface-treated and dried powder of the oxygen absorber of the present invention, prepared by the method shown in Example 6, and linear low-density polyethylene for film (made by Prime Polymer, 1020L) were mixed in a weight ratio of 40:60. This mixture was melt-kneaded in a twin-screw extruder equipped with a feeder that can be replaced with nitrogen gas, extruded into strands, and then cut with a pelletizer to obtain oxygen-absorbing resin pellets. These pellets and LLDPE were molded into a three-layer film using a T-die method with an extruder (L / D = 28). The three-layer structure was LLDPE (thickness 12.5 μm) / oxygen-absorbing resin layer (thickness 25 μm) / LLDPE (thickness 12.5 μm), meaning that the oxygen-absorbing layer was sandwiched between two LLDPE layers. The light transmittance of this film was measured with a spectrophotometer and found to be 98% at a wavelength of 700 nm and 81% at a wavelength of 450 nm, indicating high transparency.

[0055] To evaluate the gas barrier properties of the film, the oxygen permeability was measured using the isobaric method. The result was 190 cc / m².２ The oxygen-absorbing resin layer reduces the oxygen permeability of LLDPE to 4750 cc / m³. ２ It can be seen that the amount (per day) can be significantly reduced.

[0056] Furthermore, the present invention may be configured as follows: [Item 1] The following formula (1) (Mg and / or Ca) 1－ｘ (M) ｘ (OH) 2－ｎＺ (A ｎ－ ) ｚ(1) An oxygen absorber containing a magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution as an active ingredient, represented by formula (1) (wherein M represents at least one selected from divalent Fe, Mn and Co, A represents at least one n-valent [n is an integer in the range of 0 or 1 to 4] organic acid and / or organic ligand, and x and z are in the following ranges, 0 < x < 0.3, preferably 0.01 ≤ x ≤ 0.2, particularly preferably 0.02 ≤ x ≤ 0.1, 0 ≤ z < 0.1, preferably 0.001 ≤ z ≤ 0.05, particularly preferably 0.002 ≤ z ≤ 0.02). [Item 2] An oxygen absorber containing a magnesium hydroxide-based solid solution as an active ingredient, wherein in formula (1) of item 1, Mg and / or Ca is Mg. [Item 3] An oxygen absorber according to any one of items 1 to 2, wherein M in formula (1) is divalent Fe. [Item 4] An oxygen absorber according to any one of items 1 to 3, wherein A in formula (1) of item 1 is at least one selected from lactic acid, glycolic acid, ethylenediamine, and triethanolamine. [Item 5] An oxygen absorber according to any one of items 1 to 4, wherein the range of x in formula (1) of item 1 is in the range of 0.01 ≤ x ≤ 0.2. [Item 6] An oxygen absorber according to any one of items 1 to 5, wherein the width of the primary particles is 0.5 μm or more. [Item 7] An oxygen absorber according to any one of items 1 to 6, wherein the width of the primary particles is 1 μm or more. [Item 8] An oxygen absorber according to any one of items 1 to 7, which is surface-treated with at least one surface treatment agent selected from the group consisting of higher fatty acids, anionic surfactants, silane-based, titanium-based and aluminum-based coupling agents, phosphate esters, esters of polyhydric alcohols and fatty acids, silicone oil, and water glass. [Item 9] An oxygen-absorbing and / or gas-barrier resin composition containing 0.01 to 300 parts by weight of the oxygen absorbent described in any one of Items 1 to 8, per 100 parts by weight of resin. [Item 10] A resin packaging or resin container containing the oxygen absorbent described in any one of Items 1 to 9.[Item 11] A method for producing an oxygen absorber according to any one of items 1 to 8, characterized in that the entire manufacturing process is carried out under a non-oxidizing atmosphere that avoids contact with oxygen as much as possible, comprising: (1) a mixed aqueous solution of (A) a water-soluble metal salt of Mg and / or Ca and (B) at least one water-soluble metal salt selected from divalent Fe, Mn and Co (A + B), or a mixed aqueous solution of (C) an organic acid (including alkali metal salts and / or ammonium salts of organic acids) and / or an organic ligand added in an amount of 10 mol% or less relative to the total number of moles of divalent metals (A + B + C), (2) adding alkali under stirring to cause a coprecipitation reaction, (3) hydrothermally treating at 100°C or higher, and (4) filtering, washing with water and drying. [Item 12] The method for producing an oxygen absorber according to item 11, wherein the temperature and time of the hydrothermally treating are 150°C to 250°C and 1 hour to 10 hours, respectively.

[0057] Furthermore, the present invention may be configured as follows: [Item A1] The following formula (1) (Mg and / or Ca) 1－ｘ (M) ｘ (OH) 2－ｎＺ (A ｎ－ ) ｚ(1) An oxygen absorber containing a magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution as an active ingredient, wherein M represents at least one selected from divalent Fe, Mn, and Co, A represents at least one n-valent [n is an integer from 0 to 4] organic acid and / or organic ligand, and x and z are in the following ranges, 0 < x ≤ 0.2 and 0 ≤ z < 0.1, respectively. [Item A2] The oxygen absorber according to Item A1, wherein Mg and / or Ca is Mg. [Item A3] The oxygen absorber according to Item A1 or Item A2, wherein M is divalent Fe. [Item A4] The oxygen absorber according to any one of Items A1 to A3, wherein A is at least one selected from lactic acid, glycolic acid, ethylenediamine, and triethanolamine. [Item A5] An oxygen absorbent according to any one of Items A1 to A4, wherein the range of x is 0.01 ≤ x ≤ 0.2. [Item A6] An oxygen absorbent according to any one of Items A1 to A5, wherein the width of the primary particles is 0.5 μm or more. [Item A7] An oxygen absorbent according to any one of Items A1 to A6, wherein the width of the primary particles is 1 μm or more. [Item A8] An oxygen absorbent according to any one of Items A1 to A7, which is surface-treated with at least one surface treatment agent selected from the group consisting of higher fatty acids, anionic surfactants, silane-based, titanium-based and aluminum-based coupling agents, phosphate esters, esters of polyhydric alcohols and fatty acids, silicone oil and water glass. [Item A9] An oxygen-absorbing and / or gas-barrier resin composition containing 0.01 to 300 parts by weight of the oxygen absorbent according to any one of Items A1 to A8 per 100 parts by weight of resin. [Item A10] A resin packaging or resin container containing the oxygen absorber described in any one of items A1 to A8.[Item A11] A method for producing an oxygen absorber according to any one of Items A1 to A8, characterized in that the entire manufacturing process is carried out under a non-oxidizing atmosphere that avoids contact with oxygen as much as possible, comprising: (1) a mixed aqueous solution of (A) a water-soluble metal salt of Mg and / or Ca and (B) at least one water-soluble metal salt selected from divalent Fe, Mn and Co (A+B), or a mixed aqueous solution of (C) an organic acid or an alkali metal salt and / or ammonium salt of an organic acid and / or an organic ligand added in an amount of 10 mol% or less relative to the total number of moles of divalent metals (A+B+C); (2) adding alkali under stirring to cause a coprecipitation reaction; (3) hydrothermally treating at 100°C or higher; and (4) filtering, washing with water, and drying. [Item A12] The method for producing an oxygen absorber according to Item A11, wherein the temperature and time of the hydrothermally treating are 150°C to 250°C and 1 hour to 10 hours, respectively.

Claims

1. The following formula (1) (Mg and / or Ca) 1－ｘ (M) ｘ (OH) 2－ｎＺ (A ｎ－ ) ｚ (1) An oxygen absorber containing a magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution as an active ingredient, represented by the formula (wherein M represents at least one selected from divalent Fe, Mn, and Co; A represents at least one n-valent [n is an integer in the range of 0 or 1 to 4] organic acid ion moiety and / or organic ligand; and x and z are in the following ranges, 0 < x < 0.3, preferably 0.01 ≤ x ≤ 0.2, particularly preferably 0.02 ≤ x ≤ 0.1, 0 ≤ z < 0.1, preferably 0.001 ≤ z ≤ 0.05, particularly preferably 0.002 ≤ z ≤ 0.02).

2. The oxygen absorber according to claim 1, comprising a magnesium hydroxide-based solid solution as an active ingredient, wherein in formula (1), Mg and / or Ca is Mg.

3. The oxygen absorbent according to any one of claims 1 to 2, wherein in formula (1), M is divalent Fe.

4. The oxygen absorber according to any one of claims 1 to 3, wherein in formula (1), A is at least one selected from lactic acid, glycolic acid, ethylenediamine, and triethanolamine.

5. The oxygen absorber according to any one of claims 1 to 4, wherein in formula (1), the range of x is in the range of 0.01 ≤ x ≤ 0.

2.

6. The oxygen absorbent according to any one of claims 1 to 5, wherein the width of the primary particles is 0.5 μm or more.

7. The oxygen absorbent according to any one of claims 1 to 6, wherein the width of the primary particles is 1 μm or more.

8. An oxygen absorber according to any one of claims 1 to 7, wherein the surface is treated with at least one surface treatment agent selected from the group consisting of higher fatty acids, anionic surfactants, silane-based, titanium-based and aluminum-based coupling agents, phosphate esters, esters of polyhydric alcohols and fatty acids, silicone oil, and water glass.

9. An oxygen-absorbing and / or gas-barrier resin composition containing 0.01 to 300 parts by weight of the oxygen absorbent described in any one of claims 1 to 8, per 100 parts by weight of resin.

10. A resin packaging or resin container containing an oxygen absorber according to any one of claims 1 to 8, or formed in part from the resin composition according to claim 9.

11. The entire manufacturing process is carried out under non-oxidizing atmosphere conditions that avoid contact with oxygen as much as possible, (1) preparing a mixed aqueous solution (A+B) of (A) a water-soluble metal salt of Mg and / or Ca and (B) at least one water-soluble metal salt selected from divalent Fe, Mn and Co, or a mixed aqueous solution (A+B+C) to which (C) an organic acid or an alkali metal salt and / or ammonium salt of an organic acid and / or an organic ligand is added in an amount of 10 mol% or less relative to the total number of moles of divalent metals, (2) adding alkali to the mixed aqueous solution (A+B) or the mixed aqueous solution (A+B+C) under stirring to cause a coprecipitation reaction and obtain a coprecipitation product, and (3) hydrothermally treating the coprecipitation product at 100°C or higher to obtain a magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution. (4) A method for producing an oxygen absorber according to any one of claims 1 to 8, comprising preparing an oxygen absorber using the magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution.

12. The entire manufacturing process is carried out under non-oxidizing atmosphere conditions that minimize contact with oxygen: (S1) Prepare (A) an aqueous dispersion of calcium hydroxide and / or magnesium hydroxide, and (B) an aqueous solution of at least one water-soluble metal salt selected from divalent Fe, Mn, and Co. Here, optionally, (C) an organic acid or an alkali metal salt and / or ammonium salt of an organic acid and / or an organic ligand may be added to the aqueous dispersion of (A) or the aqueous solution of (B) or both, in an amount of 10 mol% or less relative to the total number of moles of divalent metals. (S2) The aqueous dispersion of (A) and the aqueous solution of (B) are reacted by mixing under stirring to obtain a magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution. Here, optionally, the magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution produced by the above reaction may be further subjected to hydrothermal treatment at 100°C or higher. (S3) A method for producing an oxygen absorber according to any one of claims 1 to 8, comprising preparing an oxygen absorber using the magnesium hydroxide-based solid solution and / or a calcium hydroxide-based solid solution.

13. The method for producing an oxygen absorber according to claim 11 or 12, wherein in (3) or (S2), one or more of the following treatments are further performed on the obtained magnesium hydroxide-based solid solution and / or calcium hydroxide-based solid solution: filtration, washing, surface treatment, drying, grinding, and classification.

14. The manufacturing method according to any one of claims 11 to 13, wherein the temperature and time of the hydrothermal treatment are 150°C to 250°C and 1 hour to 10 hours, respectively.

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