JP7286947B2 - Oxygen absorber manufacturing method, oxygen absorber, oxygen absorber package, and food package - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an oxygen absorber, an oxygen absorber, an oxygen absorber package, and a food package.

Oxygen scavengers are sometimes enclosed in food packaging containers for long-term storage of foods. Granules obtained by granulating a liquid oxygen-absorbing substance together with a carrier are known as conventional general oxygen scavengers (for example, Patent Documents 1 to 3).

Japanese Patent No. 4821692 JP-A-2003-144112 Japanese Patent No. 3541859

In order to store foods more stably, there is a demand for knowledge for further improving the oxygen absorption performance of oxygen scavengers.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing an oxygen absorber having excellent oxygen absorption performance. Another object of the present invention is to provide an oxygen absorber, an oxygen absorber package, and a food package produced by the production method.

One aspect of the present invention is a granulation step of obtaining granules containing a porous support and a liquid oxygen-absorbing composition containing an oxygen-absorbing substance and an alkaline compound, and an alkaline compound on the surface of the granules. and an attaching step of attaching particles containing to obtain composite particles.

In the production method of the present invention, the adhesion step includes a first adhesion step of forming a first particle layer by adhering first particles containing an alkaline compound to the surface of the granules, and and a second adhesion step of forming a second particle layer by adhering second particles, which are inorganic fine particles other than alkaline compounds, to obtain composite particles.

One aspect of the present invention is a granule containing a porous support and a liquid oxygen-absorbing composition containing an oxygen-absorbing substance and an alkaline compound; particles containing an alkaline compound adhered to the surface of the granule; An oxygen scavenger is provided, comprising composite particles comprising:

In the oxygen absorber of the present invention, the composite particles comprise a granule, a first particle layer containing first particles containing an alkaline compound attached to the surface of the granule, and an alkaline compound attached to the surface of the first particle layer. A second particle layer containing second particles that are inorganic fine particles other than the compound may be provided.

In the present invention, the amount of particles is preferably 5 to 33 parts by mass with respect to 100 parts by mass of the granules.

In the present invention, the total amount of alkaline compounds in the granulation step and the adhesion step, or the total amount of alkaline compounds contained in the granules and particles, is 100 parts by mass or more per 100 parts by mass of the oxygen-absorbing substance. preferable.

In the present invention, the particles may consist of an alkaline compound, and may further contain inorganic fine particles other than the alkaline compound.

One aspect of the present invention provides an oxygen absorber package comprising the above oxygen absorber and an air-permeable packaging material containing the oxygen absorber.

One aspect of the present invention provides a food package comprising the oxygen absorber package described above and a food packaging container enclosing the oxygen absorber package.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the oxygen scavenger which is excellent in oxygen absorption performance can be provided. Moreover, according to the present invention, it is possible to provide an oxygen absorber, an oxygen absorber package, and a food package manufactured by the manufacturing method.

Several embodiments of the invention are described in detail below. However, the present invention is not limited to the following embodiments.

[Oxygen absorber]
An oxygen absorber according to one embodiment includes composite particles comprising granules containing a porous support and a liquid oxygen-absorbing composition, and particles containing an alkaline compound adhered to the surface of the granules. . More specifically, the oxygen scavenger is a granule containing a porous support and a liquid oxygen-absorbing composition supported on the support, and an alkaline compound adhering to the surface of the granule. a plurality of composite particles composed primarily of particles comprising The oxygen scavenger may be powder. Here, "powder" means an aggregate composed of a large number of fine particles and maintaining fluidity as a whole. different from the mode. However, tablets obtained by compressing powder are not excluded from the oxygen scavenger of the present embodiment. The number of composite particles contained in the oxygen absorber according to the present embodiment may be, for example, 10 or more and 10000 or less per 1 g of the oxygen absorber.

The mass of each composite particle may be 0.3 mg or more, or 0.5 mg or more, and may be 10.0 mg or less, or 7.0 mg or less. Such finer composite particles tend to provide higher oxygen absorption capacity.

The support may be porous particles capable of supporting the oxygen-absorbing composition. Generally, by impregnating the carrier with the liquid oxygen-absorbing composition, the oxygen-absorbing substance and the like in the composition are supported on the carrier. The support may be, for example, a porous material derived from natural minerals such as bentonite particles, activated clay and diatomaceous earth, or a porous material derived from metal oxides such as activated alumina particles and zirconium oxide particles. In addition, the carrier may be a porous substance made of inorganic substances such as calcium silicate particles, porous silica particles (mesoporous silica particles), zeolite particles and activated carbon, or organic substances such as porous nylon particles and cellulose particles. It may be a porous substance consisting of.

The oxygen-absorbing composition contains at least an oxygen-absorbing substance and an alkaline compound.

The oxygen-absorbing substance may be liquid or solid at room temperature (eg, 5 to 35°C). When it is solid, it can be used by dissolving it in a predetermined solvent. The oxygen-absorbing substance is the main ingredient of the oxygen-absorbing composition and is a substance that absorbs oxygen. The oxygen absorbing substance may be, for example, a compound that consumes and absorbs oxygen by itself being oxidized. In this embodiment, an oxygen-absorbing substance that is liquid at room temperature or dissolved in a solvent can be used. Oxygen-absorbing substances include polyhydric alcohols, and specific examples include glycerin, 1,2-glycol, and sugar alcohols. Specific examples of 1,2-glycols include ethylene glycol and propylene glycol. Specific examples of sugar alcohols include erythritol, arabitol, xylitol, adonitol, mannitol, and sorbitol. When the oxygen-absorbing substance is solid, the solvent in which the oxygen-absorbing substance dissolves includes, for example, water; methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, secondary butanol, Lower aliphatic alcohols such as tertiary butanol and tertiary amyl alcohol; glycols such as ethylene glycol, propylene glycol and trimethylene glycol; and phenols. These oxygen-absorbing substances can be used singly or in combination.

The amount of the oxygen-absorbing substance is usually 80 to 200 parts by weight, and may be 100 to 180 parts by weight, per 100 parts by weight of the carrier. The amount of the oxygen-absorbing substance is usually 20-40% by mass, and may be 25-30% by mass, based on the total mass of the granules. When the amount of the oxygen-absorbing substance is within these ranges, it tends to be easy to obtain an oxygen scavenger having an appropriate oxygen-absorbing capacity.

Oxygen absorbing materials may require water for the reaction to absorb oxygen. Therefore, even if the oxygen-absorbing substance itself is liquid at room temperature, water is added to the oxygen-absorbing composition as necessary. The amount of water added as necessary is usually 0 to 80 parts by mass, and may be 20 to 60 parts by mass, per 100 parts by mass of the oxygen-absorbing substance. The amount of water is usually 0 to 90 parts by weight, and may be 20 to 70 parts by weight, with respect to 100 parts by weight of the carrier.

An alkaline compound is a compound that forms an alkaline aqueous solution when dissolved in water. The alkaline compound may be particulate (ie, alkaline compound particles). When the oxygen-absorbing substance has a hydroxyl group, it is believed that the hydroxyl group is ionized by the alkaline compound, thereby activating the oxygen absorption reaction. A portion of the alkaline compound may be dissolved in the liquid oxygen-absorbing composition. The alkaline compound may be an alkali metal or alkaline earth metal hydroxide, carbonate, bicarbonate, tertiary phosphate, or secondary phosphate. Alkaline compounds include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, beryllium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, radium hydroxide, lithium carbonate, sodium carbonate, selected from the group consisting of calcium carbonate, magnesium carbonate, potassium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, lithium hydrogen carbonate, tribasic sodium phosphate, tribasic potassium phosphate, dibasic sodium phosphate, and dibasic potassium phosphate It may be one or more compounds that are

Some alkaline compounds also have the function of binding the particles of the material together. In that sense, it can be said that the alkaline compound is used as an auxiliary agent when granulating the granules. When using an alkaline compound as an auxiliary agent for improving granulation properties, it is necessary to incorporate the alkaline compound into the granules. Alkaline compounds that can function as adjuvants include alkaline earth metal hydroxides, carbonates, hydrogen carbonates, tertiary phosphates, secondary phosphates, and the like.

The amount of the alkaline compound in the granules is usually 100 to 300 parts by mass, and may be 150 to 250 parts by mass, per 100 parts by mass of the carrier. Also, the amount of the alkaline compound in the granules is usually 10 to 50% by mass, and may be 20 to 40% by mass, based on the total mass of the granules. When the amount of the alkaline compound is within these ranges, it tends to be easy to obtain an oxygen scavenger having a suitable oxygen absorption capacity.

The oxygen absorbing composition can further include a transition metal compound. A transition metal compound is a compound containing a transition metal element, and is added to promote the oxygen absorption reaction of the oxygen absorbing substance. The transition metal compound may be particulate (ie transition metal compound particles). The transition metal compound may be dissolved in the liquid oxygen absorbing composition. Specific examples of transition metal elements include iron, cobalt, nickel, copper, zinc, and manganese. The transition metal compound can be, for example, a transition metal halide, sulfate, nitrate, phosphate, carbonate, organic acid salt, oxide, hydroxide, or chelate compound. The transition metal compound may be a double salt containing a transition metal element. Transition metal compounds include copper(I) chloride, copper(II) chloride, copper(II) sulfate, copper(II) hydroxide, copper(I) oxide, copper(II) oxide, manganese chloride, manganese nitrate, manganese carbonate , and nickel chloride.

The amount of the transition metal compound is usually 10 to 70 parts by mass, and may be 15 to 50 parts by mass, per 100 parts by mass of the support. Also, the amount of the transition metal compound is usually 1 to 20% by mass, and may be 1 to 15% by mass, based on the total mass of the granules. When the amount of the transition metal compound is within these ranges, it tends to be easy to obtain an oxygen scavenger having a suitable oxygen absorption capacity.

The oxygen absorbing composition may further contain a binder so that granules can be easily formed. Specific examples of binders include gum arabic, polyvinyl alcohol, sodium alginate, gelatin and cellulose. The amount of the binder is usually 0 to 30 parts by weight, and may be 10 to 20 parts by weight, per 100 parts by weight of the carrier.

The oxygen-absorbing composition may further contain other substances as necessary. Other substances include, for example, phenol compounds such as catechol, quinone compounds, and amine compounds. The amount of other substances is usually about 30 parts by mass or less with respect to 100 parts by mass of the carrier.

The particle size (maximum width) of the granules before the particles containing the alkaline compound are adhered is not particularly limited. It may be 8 mm or less, or 1.5 mm or less. A smaller particle size or size of the granules tends to provide a higher oxygen absorption capacity.

The shape of the granules is not particularly limited, but may be cylindrical, for example. In the case of cylindrical granules, the bottom diameter may be 0.3 mm or more, 4.5 mm or less, or 1.8 mm or less. The height may be 0.3 mm or more, 10 mm or less, or 5 mm or less.

Particles containing an alkaline compound are attached to the surface of the granules. The amount of deposits (particles attached to the granules) (attachment amount) is usually 5 to 33 parts by mass, and may be 10 to 25 parts by mass, with respect to 100 parts by mass of the granules. . When the amount of deposits is within these ranges, the formed deposits tend to be difficult to come off.

Examples of alkaline compounds include the compounds described above. The alkaline compound is contained in the granules and deposits, respectively, as described above. The alkaline compounds contained in the granules and the deposits are desirably of the same type, but may be of different types. Further, when other components can react with the alkaline compound, the alkaline compound in the granules and the deposit may be different.

The total amount of alkaline compounds contained in the granules and deposits (particles) is 100 parts by mass or more, and may be 100 to 300 parts by mass, or 100 to It may be 200 parts by mass, or 140 to 200 parts by mass. When the total amount of alkaline compounds is within these ranges, there is a tendency to easily obtain an oxygen absorber composition having a suitable oxygen absorption capacity.

The particles containing an alkaline compound may consist of an alkaline compound, or may further contain inorganic fine particles other than the alkaline compound. That is, the particles containing an alkaline compound may contain only particles composed of an alkaline compound, or may further contain inorganic fine particles composed of a compound other than the alkaline compound in addition to the particles composed of the alkaline compound. good too.

Inorganic fine particles are powders containing inorganic substances other than alkaline compounds as main components. The inorganic microparticles may be hydrophilic (ie, hydrophilic inorganic microparticles). Inorganic materials include, for example, silicon dioxide, calcium silicate hydrate, magnesium oxide, aluminum silicate, magnesium silicate, and calcium stearate. The inclusion of the inorganic fine particles in the adhering matter increases the surface area of the oxygen scavenger, and can expand the reaction field where the oxygen absorption reaction occurs. In addition, the inorganic fine particles also play a role in improving the fluidity of the oxygen absorber and improving the suitability for filling the package.

The average particle size of the inorganic fine particles is preferably smaller than the particle size of the granules, and may be 20 µm or less, or 5 µm or less. Although the lower limit of the average particle diameter is not particularly limited, it may be 0.1 μm or more, for example, because nano-sized fine particles are expensive and difficult to handle. The average particle size here is the value of the secondary particle size measured by a laser diffraction method.

The particles containing an alkaline compound adhering to the granules may be present on the surface of the granules as primary particles or as secondary particles having a particle size of several μm to several tens of μm. In addition, the particles may coat the granules continuously (layered) or intermittently. In addition, the particles containing the alkaline compound may be present on the surface of the oxygen scavenger independently of each other. The term "mutually independent state" refers to a state in which the particles are not mixed with the porous carrier contained in the granules and are attached to the surface of the oxygen scavenger.

The deposit may have a laminated structure. Specifically, the composite particles contained in the oxygen absorber are composed of a granule, a first particle layer containing first particles containing an alkaline compound adhered to the surface of the granule, and and a second particle layer containing second particles that are inorganic fine particles other than the adhered alkaline compound. By adopting such a laminated structure, there is a tendency to easily obtain an oxygen absorber having an excellent oxygen absorption capacity. From this point of view, it is preferable that the first particle layer is a layer of particles comprising an alkaline compound, and the second particle layer is a layer of particles comprising inorganic fine particles other than the alkaline compound.

In this case, the amount of deposits (first particles and second particles attached to the granules) is usually 5 to 33 parts by mass, and 10 to 25 parts by mass, with respect to 100 parts by mass of the granules. may be When the amount of deposits is within these ranges, the formed deposits tend to be difficult to come off.

[Oxygen absorber package]
An oxygen absorber package according to one embodiment can be mainly composed of the oxygen absorber according to the above embodiment and an air-permeable packaging material containing the oxygen absorber. The air-permeable wrapping material can be appropriately selected from those commonly used in the technical field. Specific examples of air-permeable packaging materials include bags made of a base material made of perforated plastic film, nonwoven fabric, microporous film, paper, or a combination thereof. This oxygen absorber package can be housed in, for example, various food packaging containers and used for the purpose of maintaining the freshness of food.

[Food packaging]
A food package according to one embodiment includes the above oxygen absorber package and a food packaging container in which the oxygen absorber package is enclosed. The food packaging container can be appropriately selected from those commonly used in the field of food packaging, and a sealable container is suitable. Food packaging containers include bags, deep drawn packages, tray packages, stretch packages and the like.

[Method for producing oxygen scavenger]
A method for producing an oxygen absorber according to one embodiment includes a granulation step of obtaining granules containing a porous support and a liquid oxygen-absorbing composition containing an oxygen-absorbing substance and an alkaline compound; and an attaching step of attaching particles containing an alkaline compound to the surface of to obtain composite particles. By properly distributing the alkaline compound between the inside of the granules and the outside of the granules (on the surface of the granules), it is possible to improve the oxygen absorption performance while maintaining the granulation properties. Incidentally, by allowing a part of the alkaline compound to be included in the granules to adhere to the surface of the granules, the oxygen absorption performance can be improved without changing the total amount of the alkaline compounds. This is an unexpected result.

In the granulation step, a mixture containing the carrier and components constituting the liquid oxygen-absorbing composition is granulated. Each component may be mixed at once or may be mixed several times for each component. The mixer is not particularly limited, and may be, for example, a container rotation type mixer such as a cylindrical type or a V type, or a fixed container type such as a ribbon type, horizontal screw type, paddle type, or planetary motion type. It may be a mixer. Granulation can be carried out using a granulator, for example, by extrusion granulation using a screen having predetermined apertures.

In the adhesion step, the granules obtained in the granulation step are mixed with particles containing an alkaline compound. This makes it possible to obtain composite particles (particles constituting the oxygen absorber) by adhering particles containing an alkaline compound to the surface of the granules. When particles other than the alkaline compound are contained in the particles, the particles may be mixed in advance and mixed with the granules, or each type of particle may be divided several times and mixed with the granules. You may The device for mixing is not particularly limited, and may be, for example, a cylindrical or V-shaped container rotating mixer, a ribbon type, a horizontal screw type, a paddle type, a planetary motion type, or the like. It may be a fixed container type mixer.

Particles may be attached to the granules in two stages. That is, the adhesion step includes a first adhesion step of forming a first particle layer by adhering particles containing an alkaline compound to the surface of the granules, and inorganic fine particles other than the alkaline compound on the surface of the first particle layer. to form a second particle layer to obtain composite particles. The first and second deposition steps may be performed according to the deposition steps described above.

Other matters related to the support, the oxygen-absorbing composition, the alkaline compound, the inorganic fine particles, etc. are as described in the section on the oxygen scavenger.

Hereinafter, the present invention will be described more specifically with reference to Examples (Examples 1 to 3 are Reference Examples) . However, the present invention is not limited to these examples.

1. Preparation of Granules Containing Oxygen-Absorbing Substance Raw materials for the granules were uniformly mixed in a powder-liquid mixer to obtain glycerin, activated carbon, calcium hydroxide, cellulose, copper (II) sulfate pentahydrate and water. A mixed mixture was obtained. The obtained mixture was granulated by an extrusion granulator equipped with a screen having a screen hole diameter of 1.0 mmφ and a porosity of 22.6% to obtain granules containing an oxygen-absorbing substance. The mixing ratio of raw materials was as shown in the table.

2. Application of Attachment Silica particles (average particle size: 3.9 μm) were prepared as inorganic fine particles, and calcium hydroxide (average particle size: 5.2 μm) was prepared as an alkaline compound. The prepared silica particles and calcium hydroxide were uniformly mixed in a sealed state to obtain a raw material powder. Next, the granules and the powder raw material were uniformly mixed in a hermetically sealed state, and the powder raw material was adhered to the surface of the granules to form composite particles, thereby obtaining an oxygen scavenger. The amount of adhered particles was as shown in the table. In Comparative Example, calcium hydroxide was not adhered.

3. Evaluation Method of Oxygen Absorption Performance 3.0 g of oxygen absorber was placed in a bag (length 60 mm, width 60 mm) formed of a perforated packaging material to prepare an oxygen absorber package. A laminated material composed of polyethylene terephthalate/polyethylene/paper/polyethylene was used as the perforated packaging material. The oxygen absorber package was placed in a gas barrier bag together with absorbent cotton (water activity 0.95) soaked with a 44% sucrose aqueous solution. After sealing the bag and injecting 500 mL of air into it, the bag was left in an atmosphere at 25°C. After 24 hours, the oxygen concentration in the bag was measured using an oxygen concentration meter. Low oxygen concentration means high oxygen absorption performance.

4. Results Table 1 shows the raw material compounding ratio of the granules containing the oxygen-absorbing substance and the adhering matter, and the evaluation results of the oxygen absorbing performance at each compounding ratio. The blending amount of raw materials in Table 1 represents the mass of glycerin, which is an oxygen-absorbing substance, as 100 parts by mass.

Table 2 shows the evaluation results when the total content of calcium hydroxide was reduced from 126 parts by mass (when verifying Table 1) to 103 parts by mass.

Table 3 shows the evaluation results when only silica particles were used as deposits and when only calcium hydroxide was used.

5. Application of Deposit A and Deposit B As a further verification, the deposit is a laminated structure of deposit A (first particle layer) made of calcium hydroxide and deposit B (second particle layer) made of silica particles. Oxygen absorption performance was confirmed.

Silica particles (average particle size: 3.9 µm) were prepared as inorganic fine particles, and calcium hydroxide (average particle size: 5.2 µm) was prepared as an alkaline compound. Next, the granules containing the oxygen-absorbing substance and calcium hydroxide were uniformly mixed in a sealed state, and calcium hydroxide powder was deposited around the granules to form deposit A. Next, the silica particles and the granulated matter to which the adhering matter A was applied were uniformly mixed in a sealed state, and the silica particles were adhered around the adhering matter A to form the adhering matter B. As a result, an oxygen absorber having a laminate structure was obtained.

6. Results Table 4 shows the raw material compounding ratios of the granules, deposits A and deposits B, and the evaluation results of the oxygen absorption performance. As in Table 1, the amounts of raw materials to be blended are expressed with the mass of glycerin, which is an oxygen-absorbing substance, being 100 parts by mass.

Claims (6)

a granulation step of obtaining granules containing a porous support and a liquid oxygen-absorbing composition containing an oxygen-absorbing substance and an alkaline compound;
a first adhesion step of adhering first particles containing an alkaline compound to the surface of the granules to form a first particle layer; and inorganic fine particles other than the alkaline compound on the surface of the first particle layer a second attachment step of attaching the second particles to form the second particle layer to obtain the composite particles;
A method for producing an oxygen absorber, wherein the alkaline compound contains calcium hydroxide . 2. The manufacturing method according to claim 1, wherein said first particles comprise said alkaline compound. Granules comprising a porous support and a liquid oxygen-absorbing composition comprising an oxygen-absorbing substance and an alkaline compound;
A first particle layer containing first particles containing an alkaline compound adhering to the surface of the granules, and a second particle containing second particles that are inorganic fine particles other than the alkaline compound adhering to the surface of the first particle layer. a composite particle comprising a layer ;
An oxygen scavenger, wherein the alkaline compound comprises calcium hydroxide . 4. The oxygen scavenger according to claim 3, wherein said first particles comprise said alkaline compound. An oxygen absorber package comprising: the oxygen absorber according to claim 3 or 4 ; and an air-permeable packaging material containing the oxygen absorber. A food package comprising: the oxygen absorber package according to claim 5 ; and a food packaging container enclosing the oxygen absorber package.