JP7020270B2 - Oxygen scavenger and oxygen scavenger packaging, as well as food packaging - Google Patents

Description

The present invention relates to a powdered oxygen scavenger and an oxygen scavenger package in which the oxygen scavenger is packed and packaged in a small bag. More specifically, a powdered oxygen scavenger containing an organic oxygen absorber, a reaction catalyst, an alkaline compound and a carrier as main components, and an oxygen scavenger package in which the oxygen scavenger is packed and packaged in a pouch. Regarding food packaging.

In food packaging, as one of the methods to prevent the growth of mold and oxidative deterioration of food and extend the shelf life of food, an oxygen scavenger package is enclosed in the food packaging to make the oxygen concentration in the package extremely high. Techniques are being taken to reduce it. Specifically, the oxygen scavenger is filled in a highly breathable pouch and sealed, and this pouch is placed in a food packaging container with a high oxygen barrier property together with food and the like to seal and seal the oxygen in the packaging container. Can be absorbed by the oxygen scavenger package to make the oxygen concentration in the packaging container almost 0%.

Achieving the same purpose can be attempted by nitrogen-replacement packaging in which the air in the packaging container is replaced with nitrogen when filling and packaging food, but plastic or paper containers and bags are used except for metal canned containers and the like. Even if a material having a high oxygen barrier property is used, the invasion of oxygen into the packaging container cannot be completely eliminated, and a small amount of oxygen permeation occurs. Therefore, even if the initial oxygen concentration is lowered as much as possible by nitrogen substitution, the oxygen concentration in the packaging container gradually increases due to the oxygen that invades later.

On the other hand, when the oxygen scavenger package is enclosed in the packaging container, not only the oxygen remaining in the packaging container at the time of enclosing but also the oxygen that later invades the packaging container is absorbed, so that the oxygen scavenger is used. It is possible to keep the oxygen concentration close to 0% for a certain period within the range of the oxygen absorption capacity of the above. However, in a packaging container having a low oxygen barrier property, the oxygen absorption capacity of the oxygen scavenger will soon reach its limit, so it is necessary to use it in combination with a packaging container having a high oxygen barrier property to some extent.

There are roughly two types of oxygen scavengers that are commonly used at present, and there are inorganic oxygen scavengers whose main component is iron and organic oxygen scavengers whose main component is ascorbic acid-based oxygen absorbers. .. Each is used properly according to the purpose and target food, but in recent years there has been an increasing need to apply products to metal detectors, so the demand for organic oxygen scavengers that can be applied to metal detectors has increased. There is.

However, the organic oxygen scavenger has a drawback that the oxygen absorption rate is slower than that of the iron oxygen scavenger. When used as an oxygen scavenger for the purpose of improving food preservation, in order to suppress the growth of mold that grows in 24 to 48 hours at the earliest, the oxygen concentration should be reduced to nearly 0% within 24 hours. It is desirable to keep it. Therefore, in the case of organic oxygen scavengers, how to increase the oxygen absorption rate has been one of the problems.

Therefore, in order to increase the oxygen absorption rate of the organic oxygen scavenger, a reaction catalyst that promotes the oxidation reaction of the oxygen absorbing substance has been added, and an alkaline compound has been added to obtain the optimum PH. As one of them, a device to provide a reaction field with improved air permeability to allow the association of oxygen and the oxygen absorbing composition (containing a liquid agent containing an oxygen absorbing substance, an alkaline compound, and a reaction catalyst) to occur rapidly is also considered. There is. It is effective to use a porous material as a carrier in order to provide a highly breathable reaction field, and it is possible to increase the oxygen absorption rate as the specific surface area of the porous material is increased. Activated carbon, diatomaceous earth, and the like are used as these porous materials.

Further, the oxygen scavenger for food packaging is used by filling and packaging in a highly breathable pouch, and the filling and packaging in the pouch is continuously mechanically filled. At this time, if the fluidity of the oxygen scavenger is poor or if it is easily scattered, the continuous machine filling of the pouch will be hindered. For example, if the fluidity is poor, the hopper or filling nozzle of the filling machine may be clogged with oxygen scavenger powder and filling may stop. .. In the present invention, in-process defects due to powder scattering are expressed as "powder dance".

Therefore, at present, in most cases, organic oxygen scavengers have been devised to improve fluidity and suppress powder dance by granulating and granulating powder. However, the granulated oxygen scavenger also has a problem that the oxygen absorption rate is lower than that of the powder. Patent Document 1 discloses an example of granulation of an oxygen scavenger and a decrease in the oxygen absorption rate after granulation.

Japanese Unexamined Patent Publication No. 59-45861 Japanese Unexamined Patent Publication No. 2011-72890 Japanese Unexamined Patent Publication No. 2017-159271

As described above, in the case of organic oxygen scavengers, it is the most important issue to achieve both improvement of oxygen absorption rate and improvement of suitability for automatic filling machine. When an oxygen absorbing composition (containing a liquid agent containing an oxygen absorbing substance, an alkaline compound, and a reaction catalyst) is supported on a porous material, the oxygen absorption rate is improved, but this powder is prepared in order to improve the suitability for a filling machine. When granulated, the oxygen absorption rate decreases again, and so far it has been difficult to achieve both.

Therefore, a device for filling and packaging the powder as it is without granulation is being studied.
In Patent Document 2, although the main agent is an iron-based oxygen scavenger, in an oxygen scavenger that is easily powdered by containing activated carbon, it is filled by suppressing powdering by using activated carbon containing a saturated amount of water. Oxygen scavengers that can be packaged are disclosed. However, according to our verification results, even if activated carbon with a high water content is used in the organic oxygen scavenger, the powder dance cannot be completely suppressed, and the water or liquid in the humidified powder is not completely suppressed. It has also been shown that as the fraction ratio increases, the fluidity deteriorates and clogging in the hopper and filling nozzle becomes more likely to occur. Simply increasing the water and liquid content ratio suppresses powder dance and improves fluidity. It seems difficult to achieve both.

Further, in Patent Document 3, the fluidity is improved by mixing iron oxide as a filler with iron powder which is an oxygen absorbing substance in an iron-based oxygen scavenger, and the iron oxide filler has a specific gravity of about 5 g / ml. Discloses an oxygen scavenger capable of improving fluidity and powdering at the same time without the filler itself being powdered. However, if this is used as an organic oxygen scavenger, iron oxide is used because the specific gravity of the organic oxygen scavenger including the porous carrier is about 0.5 to 0.6 g / ml as described above. The difference in specific gravity with the filler is too large, and it is difficult to uniformly mix the powder and the filler. Since the principle of improving the fluidity by the filler is exhibited by uniformly dispersing and mixing the filler particles between the main particles, a system in which uniform mixing is difficult is fatal.

From the above, the problem to be solved in the present invention is to provide a means for simultaneously improving the fluidity and the powder dance in the organic oxygen scavenger containing the porous carrier, and the powder remains as it is. It is to provide a means for obtaining a deoxidizing agent which can be filled in a pouch and has good oxygen absorption performance.

One aspect of the present invention is
A porous carrier and a powder containing an oxygen absorbing composition supported on the carrier,
It is provided with inorganic fine particles adhering to the surface of the powder.
The average particle size of the powder is 0.01 mm or more and less than 0.3 mm.
The amount of the inorganic fine particles added is 12.0 wt% or less of the total weight of the oxygen scavenger.
The oxygen absorbing composition provides a liquid agent containing an oxygen absorbing substance and an oxygen scavenger containing an alkaline compound and a transition metal compound.

Another aspect of the present invention is that the ratio (B / A) of the average particle size A of the powder containing the oxygen absorbing composition supported on the carrier and the average particle size B of the inorganic fine particles is 1/30. Provided is an oxygen scavenger having a value of 2/5 or less.

Another aspect of the present invention is to provide an oxygen absorber characterized in that the amount of the oxygen absorbing substance is 80 to 200 parts by mass with respect to 100 parts by mass by mass of the carrier.

Another aspect of the present invention provides an oxygen scavenger, characterized in that the amount of the alkaline compound is 100 to 300 parts by mass with respect to 100 parts by mass of the carrier.

Another aspect of the present invention provides an oxygen scavenger, characterized in that the amount of the transition metal compound is 10 to 70 parts by mass with respect to 100 parts by mass of the carrier.

Another aspect of the present invention provides an oxygen scavenger characterized by an angle of repose of 40 ° or less.

Another aspect of the present invention provides an oxygen scavenger package comprising the oxygen scavenger and a breathable packaging material containing the oxygen scavenger.

Another aspect of the present invention provides a food package including the oxygen scavenger package and a food package container for enclosing the oxygen scavenger package.

According to the present invention, by adhering the inorganic fine particles to the surface of the powder, the fluidity of the oxygen scavenger can be improved, and the oxygen scavenger that is hard to be powdered can be provided.

Hereinafter, some embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

The powdery deoxidizer according to the embodiment of the present invention is attached to a porous carrier, a powder containing an oxygen absorbing composition supported on the carrier, and the surface of the powder. It is a powder containing a plurality of composite particles mainly composed of inorganic fine particles. Here, "powder" means an aggregate that is composed of a large number of fine particles and maintains fluidity as a whole.

The carrier may be any porous powder that can support the oxygen absorbing composition. Usually, the oxygen absorbing composition is supported on the carrier by impregnating the carrier with the oxygen absorbing composition.
The carrier is selected from, for example, activated charcoal, zeolite particles, bentonite particles, activated alumina particles, activated clay, calcium silicate particles, and diatomaceous earth.

The oxygen absorbing composition contains a liquid containing an oxygen absorbing substance, an alkaline compound, and a transition metal compound.

The liquid agent containing the oxygen absorbing substance may be a liquid oxygen absorbing substance at room temperature (for example, 5 to 35 ° C.), or may be a solution containing a liquid or solid oxygen absorbing substance.
The oxygen absorbing substance is the main agent of the oxygen absorbing composition and is a substance that absorbs oxygen. The oxygen absorbing substance may be, for example, a compound that consumes oxygen by oxidizing itself and absorbs oxygen. In this embodiment, an oxygen absorbing substance that is liquid at room temperature or dissolved in a solvent can be used.

Such an oxygen absorbing substance is, for example, one or more compounds selected from the group consisting of glycerin, 1,2-glycol, and sugar alcohol. Specific examples of 1,2-glycol include ethylene glycol and propylene glycol. Specific examples of sugar alcohols include erythritol, arabitol, xylitol, adonitol, mannitol, and sorbitol.

When the liquid agent is a solution of an oxygen absorbing substance, the solvent in which the oxygen absorbing substance is dissolved includes, for example, water; methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, secondary butanol, and the like. Lower aliphatic alcohols such as tertiary butanol and tertiary amyl alcohol; glycols such as ethylene glycol, propylene glycol and trimethylene glycol; and phenol. The oxygen absorber can be used alone or in combination of two or more.

The amount of the oxygen absorbing substance is usually 80 to 200 parts by mass with respect to 100 parts by mass of the carrier, and may be 100 to 180 parts by mass. 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 absorbers may require water for reactions that absorb oxygen. Therefore, even if the oxygen absorbing substance itself is a liquid at room temperature, water can be added to the liquid agent as needed. The amount of water added as needed is usually 0 to 80 parts by mass and may be 20 to 60 parts by mass with respect to 100 parts by mass of the oxygen absorbing substance. The amount of water is usually 0 to 90 parts by mass and may be 20 to 70 parts by mass with respect to 100 parts by mass of the carrier.

An alkaline compound is a compound that forms an alkaline aqueous solution when dissolved in water. When the oxygen absorbing substance has a hydroxyl group, the oxygen absorption reaction is activated by ionizing the hydroxyl group with an alkaline compound. In the state of the oxygen absorbing composition, a part of the alkaline compound is often dissolved in a liquid containing an oxygen absorbing substance.
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 hydrogencarbonate, sodium hydrogencarbonate, lithium hydrogencarbonate, sodium tertiary phosphate, potassium tertiary phosphate, sodium secondary phosphate, and potassium secondary phosphate. It may be one or more compounds.

The amount of the alkaline compound is usually 100 to 300 parts by mass with respect to 100 parts by mass of the carrier, and may be 150 to 250 parts by mass. When the amount of the alkaline compound is within these ranges, it tends to be easy to obtain an oxygen scavenger composition having an appropriate oxygen absorption capacity.

The transition metal compound is a compound containing a transition metal element, and is added as a reaction catalyst in order to promote the oxygen absorption reaction of the oxygen absorbing substance. In the state of the oxygen absorbing composition, the transition metal compound is often dissolved in a liquid agent containing an oxygen absorbing substance. Specific examples of transition metal elements include iron, cobalt, nickel, copper, zinc, and manganese.
The transition metal compound may be, for example, a halide, sulfate, nitrate, phosphate, carbonate, organic acid salt, oxide, hydroxide, or chelate compound of the transition metal. The transition metal compound may be a double salt containing a transition metal element. The 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, and manganese carbonate. , And one or more compounds selected from the group consisting of nickel chloride.

The amount of the transition metal compound is usually 10 to 70 parts by mass and may be 30 to 50 parts by mass with respect to 100 parts by mass of the carrier. When the amount of the transition metal compound is within these ranges, it tends to be easy to obtain an oxygen scavenger having an appropriate oxygen absorbing capacity.

The oxygen absorption composition may further contain other substances if necessary. Examples of other substances include binders. Specific examples of the binder include gum arabic, polyvinyl alcohol, sodium alginate, gelatin and cellulose. 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 average particle size of the powder containing the carrier and the oxygen absorbing composition before the inorganic fine particles adhere is not particularly limited, but is, for example, 0.01 mm or more and less than 0.3 mm, or 0.05 mm or more and less than 0.2 mm. There may be.
The average particle size is a value measured based on the laser diffraction / scattering method.

The powder containing the carrier and the oxygen absorbing composition can be obtained by mixing each component constituting the carrier and the oxygen absorbing composition. The components constituting the powder may be mixed together or separately. The mixer for mixing is not particularly limited, and may be, for example, a container rotary type mixer such as a cylindrical type or a V type, a ribbon type, a horizontal screw type, a paddle type, or a planetary motion type. It may be a container fixed type mixer such as.

Inorganic fine particles are powders containing an inorganic substance as a main component. Examples of the inorganic substance include silicon dioxide, calcium silicate hydrate, magnesium oxide, aluminum silicate, magnesium silicate, and calcium stearate. One type of inorganic fine particles may be used, or two or more types may be mixed and used.

In the oxygen scavenger according to the present invention, the inorganic fine particles are adhered to the surface of the powder by mixing the powder composed of the carrier and the oxygen absorbing composition produced as described above with the inorganic fine particles. ,Obtainable. The device for mixing is not particularly limited, and may be, for example, a container rotary type mixer such as a cylindrical type or a V type, a ribbon type, a horizontal screw type, a paddle type, a planetary motion type, or the like. It may be a container-fixed type mixer.

Before the inorganic fine particles adhere, the surface of the powder containing the carrier and the oxygen absorbing composition is moistened with a liquid agent containing an oxygen absorbing substance or water, and the wet alkaline compound and other constituents are contained in the powder. It is considered that the fluidity of the powder is reduced by binding the powders together.
By adhering the inorganic fine particles to the surface of the powder, fine surface irregularities due to the inorganic fine particles are formed on the surface of the powder, and as a result, the area where the powders come into contact with each other is reduced and binding is suppressed. It is considered that the fluidity of the powdered oxygen scavenger is finally improved.

From such a viewpoint, the average particle size of the inorganic fine particles is preferably smaller than the particle size of the powder, and may be 20 μm or less, or 5 μm or less. The lower limit of the average particle size is not particularly limited, but it is, for example, 0.1 μm or more because the price of nano-sized fine particles increases and it is difficult to handle because they are taken into the human body from the skin surface. May be good.
Further, as for the size of the inorganic fine particles with respect to the powder, it is preferable that the ratio (average particle size of the inorganic fine particles) / (average particle size of the powder) is 1/30 or more and 2/5 or less. Within this range, the fluidity of the oxygen scavenger is further improved for the above reason, and the suitability for the automatic filling machine is also good.

The amount (adhesion amount) of the inorganic fine particles attached to the surface of the powder containing the carrier and the oxygen absorbing composition may be 0.1 wt% or more with respect to the total weight of the powdered oxygen scavenger. When the amount of the inorganic fine particles is within this range, a powdery oxygen scavenger having good fluidity can be obtained. The upper limit of the amount of the inorganic fine particles adhering to the surface of the powder is not particularly limited, but when excessively added, the inorganic fine particles that could not be completely adhered to the surface of the powder are left over, and the surplus inorganic fine particles are in the form of powder. It is possible that the deoxidizing agent is scattered during the process of filling the package and adheres to the heat-sealed part for sealing the package, causing a sealing failure or contaminating the filling machine with the scattered fine particles. The sex becomes high. From this point of view, it may be 8.0 wt% or less.

The angle of repose is an index showing the fluidity of the powdered oxygen scavenger. The angle of repose refers to the angle at which the hill-shaped deposits formed when the powder is dropped form a horizontal plane. It is generally known that when the angle of repose of the powder is sharper than the inclination angle of the hopper of the filling machine, the powder falls smoothly without being clogged in the hopper. Further, the inclination angle of the hopper of the filling machine in the organic oxygen scavenger may be about 40 ° or more depending on the filling machine, and the angle of repose of the powdered oxygen scavenger is 40 ° or less. Things are desirable.

The oxygen scavenger package according to one embodiment of the present invention may be mainly composed of the oxygen scavenger composition according to the above embodiment and a breathable packaging material containing the oxygen scavenger. The breathable packaging material can be appropriately selected from those commonly used in the art. Specific examples of the breathable packaging material include a bag made of a perforated plastic film, a non-woven fabric, a microporous film, paper, or a base material made of a combination thereof. This oxygen scavenger package can be stored in various food packaging containers, for example, and used for the purpose of maintaining the freshness of food.

Further, the food package according to the embodiment of the present invention includes the above-mentioned oxygen scavenger package and a food package container in which the oxygen scavenger package is enclosed. The food packaging container can be appropriately selected from those usually used in the field of food packaging, and a sealable container is preferable. Examples of the food packaging container include a bag body, a deeply squeezed package body, a tray package body, a stretch package body and the like.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Examples 1 to 5, Comparative Examples 1 to 3)
1. 1. Preparation of powder containing carrier and oxygen absorption composition The raw materials shown in Table 1 are uniformly mixed in a sealed state to obtain activated carbon, glycerin, calcium hydroxide, copper (II) sulfate pentahydrate, water and cellulose. A mixed powder was obtained.
Table 1 shows the blending amount of each raw material in the powder.

2. 2. Addition of Inorganic Fine Particles Silica particles (average particle size 8.5 μm) were prepared as inorganic fine particles. The prepared inorganic fine particles and the powder shown in Table 1 were uniformly mixed in a sealed state to obtain a powdery oxygen scavenger.
In Examples 1 to 5 and Comparative Examples 1 to 3, the added amount (1.0 to 16.0 wt%) of the inorganic fine particles shown in Table 2 was added to the total weight of the oxygen scavenger, and the angle of repose thereof was added. And the scattering situation of fine powder was evaluated. The angle of repose is evaluated to confirm the fluidity of the powdered oxygen scavenger. The scattering status of fine powder is evaluated to confirm the occurrence of powder dance.

3. 3. How to evaluate the angle of repose From a height of 23 cm from the surface of the work table, through a funnel with an inner diameter of 26 mm on the smaller side, to a cylindrical container with an inner diameter of 45 mm and a depth of 66 mm installed on the work table, 2 Approximately 150 g of powdered oxygen scavenger is dropped over ~ 4 seconds, powdered oxygen scavenger is deposited in the cylindrical container, and finally the hill-shaped deposit formed on the cylindrical container becomes a horizontal plane. The angle of repose was measured and used as the angle of repose.

4. Evaluation method of scattering of fine powder The scattering state of smoke-like fine powder at the time of measuring the angle of repose was observed and evaluated. Specifically, from a height of 23 cm from the surface of the workbench, through a funnel with an inner diameter of 26 mm on the small side installed on the workbench, to a cylindrical container with an inner diameter of 45 mm and a depth of 66 mm, 2 When about 150 g of powdered oxygen scavenger is freely dropped over ~ 4 seconds and the powdered oxygen scavenger is deposited in a cylindrical container, smoke-like fine powder is scattered before and after passing through the funnel. / Nothing was visually confirmed.
"None" if there is no scattering of smoke-like fine powder, "Slightly" if scattering of smoke-like fine powder is confirmed with a horizontal spread within a radius of 10 cm from the center of the cylindrical container to the outside. "Yes", and when it was confirmed that smoke-like fine powder was scattered with a radius of 10 cm or more in the horizontal direction, it was determined to be "Yes".

5. Results (Examples 1 to 5, Comparative Examples 1 to 3)
Table 2 shows the evaluation results of the angle of repose and the scattering of the fine powder depending on the amount of the inorganic fine particles added. The pass / fail judgment of the fluidity was judged to be good when the angle of repose was 40 ° or less, and was judged as ◯. The pass / fail judgment of the powder dance was judged to be good when there was no scattering of fine powder, and was judged as ◯.
In addition, Table 2 shows the evaluation results without the addition of inorganic fine particles as a comparative example.

From Examples 1 to 5, when silica particles were used as the inorganic fine particles, an oxygen scavenger having an angle of repose of 40 ° or less could be obtained in the range of an addition amount of 1.5 to 16.0 wt%, and the inorganic fine particles could be obtained. It was confirmed that the fluidity of the oxygen scavenger could be improved by the addition. Further, when the addition amount was 12.0 wt% or more, it was confirmed that the fine powder was scattered, and it was considered that the addition of the inorganic fine particles exceeding 12.0 wt% was not preferable.
Further, in Comparative Examples 1 and 2 in which the amount of inorganic fine particles is 1.0 wt% or less, the angle of repose exceeds 40 ° and the fluidity is not good. Further, in Comparative Example 3 in which the amount of the inorganic fine particles added was 16 wt%, scattering of fine powder was observed.

Claims (8)

A porous carrier and a powder containing an oxygen absorbing composition supported on the carrier,
It is provided with inorganic fine particles adhering to the surface of the powder.
The average particle size of the powder is 0.01 mm or more and less than 0.3 mm.
The amount of the inorganic fine particles added is 12.0 wt% or less of the total weight of the oxygen scavenger.
An oxygen scavenger, wherein the oxygen absorbing composition contains a liquid agent containing an oxygen absorbing substance, an alkaline compound, and a transition metal compound. The ratio (B / A) of the average particle size A of the powder containing the oxygen absorbing composition supported on the carrier and the average particle size B of the inorganic fine particles is 1/30 or more and 2/5 or less. The oxygen scavenger according to claim 1. The oxygen scavenger according to claim 1 or 2, wherein the amount of the oxygen absorbing substance is 80 to 200 parts by mass with respect to 100 parts by mass of the carrier. The oxygen scavenger according to any one of claims 1 to 3, wherein the amount of the alkaline compound is 100 to 300 parts by mass with respect to 100 parts by mass of the carrier. The oxygen scavenger according to any one of claims 1 to 4, wherein the amount of the transition metal compound is 10 to 70 parts by mass with respect to 100 parts by mass of the carrier. The oxygen scavenger according to any one of claims 1 to 5, wherein the angle of repose is 40 ° or less. An oxygen scavenger package comprising the oxygen scavenger according to any one of claims 1 to 6 and a breathable packaging material containing the oxygen scavenger. A food package comprising the oxygen scavenger package according to claim 7 and a food package container for enclosing the oxygen scavenger package.