JPH09268235A - Deoxygenation resin composition and packaging material, multilayer packaging material, package product and packaging method using the resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a deoxygenation resin composition capable of achieving sufficient oxygen-absorption reaction even in an environment having low water content and to provide as packing material utilizing the resin composition, a packaging method and a packaged material. SOLUTION: This deoxygenation resin composition contains a resin and a deoxygenation agent produced by coating iron powder with sodium iodide or potassium iodide. A multilayer film produced from the resin composition contains the iron particles coated with sodium iodide, etc., in a deoxygenation resin layer 4. The use of sodium iodide or potassium iodide as a main component of the reaction accelerator of the deoxygenation agent gives a multilayer film capable of sufficiently absorbing oxygen in an environment having low water content.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an oxygen absorbing resin composition containing an oxygen absorbing agent and a thermoplastic resin. The present invention also relates to a packaging material made of this resin composition. Further, the present invention relates to a packaging body and a packaging method for using the packaging material to store a dried content (mainly a dry food) having a low water content.

[0002]

2. Description of the Related Art Oxygen scavengers utilizing the oxidation reaction of reducing metals have been widely known. This oxygen scavenger is provided with a metal halide as an activator that accelerates the oxidation reaction of the reducing metal in addition to the reducing metal.

This type of oxygen scavenger is mainly used for preserving the freshness of foods and the like, and is used together with an object to be preserved such as foods in containers,
Alternatively, it is put in a packaging material, or a deoxidizer is put in a container or a sheet material, and a food or the like to be preserved is packaged using this.

Japanese Patent Publication No. 56-33980 discloses an oxygen absorbent in which metal powder is coated with a metal halide. Since the deoxygenation reaction by reducing metals requires the presence of water, this type of oxygen scavenger is used for the preservation of high (high) water content foods that can utilize the water evaporated from the preserved material. There is.

On the other hand, in order to store dry foods having a low water content (in other words, having a low water activity ( _aw )), it is necessary to allow a water donor to exist in the oxygen absorber to carry out the oxygen absorption reaction. I was trying to make up for it. This type of oxygen scavenger is known as a self-reactive type that can absorb oxygen without depending on moisture from the object to be packaged.

[0006]

In recent years, it has been practiced to package an object to be preserved using a sheet-shaped packaging material which is formed into a sheet or film by kneading an oxygen scavenger with a resin.
However, when a self-reactive oxygen scavenger that retains water is used to store stored items with low water content, it is unavoidable that the water in the water retention component migrates to the stored items. However, there are problems such as deterioration of taste of food to be preserved (moisture) due to moisture, change of properties (agglomeration of powder), chemical change (hydrolysis), propagation of microorganisms, and the like. In some cases, there is a problem that the oxygen absorber cannot lose the water content necessary for deoxidation and oxygen cannot be absorbed.

[0007] Further, not only the water in the water-retaining component is evaporated by the heating when the self-reactive oxygen scavenger having water is kneaded with the resin to form a sheet, but also the foamed resin causes bubbles in the resin sheet. However, there is a problem that unevenness occurs on the surface of the sheet and the surface properties of the sheet are not good.

On the other hand, even if a sheet material is obtained by kneading a deoxidizing agent (moisture-dependent type) that does not retain water with the resin, in order to exert or function the deoxidizing ability, it is necessary to retain water in this deoxidizing agent. However, when the resin sheet is allowed to retain water, the deoxidized resin sheet
Only the drawbacks of the self-reactive oxygen scavenger described above could be taken over as they were.

[0009] Therefore, in practice, the conventional deoxidizing sheet material absorbs oxygen by obtaining the water content from a high-moisture food product which does not contain water itself and contains the water necessary for the oxygen absorption reaction. However, it was usually applicable only to foods containing a lot of water.

Under these circumstances, it has been difficult for a person skilled in the art to realize a deoxidizing sheet which can achieve a deoxidizing reaction even in an environment of low moisture. In short, depending on the conventional oxygen scavenger, it has been difficult to satisfactorily package a dried food product, in other words, an object to be preserved having a low water content under a low oxygen condition.

The inventors of the present invention have made extensive studies in order to solve this problem. As a result, they have been found to be inferior to chlorides such as calcium chloride and sodium chloride as conventional accelerators for the oxygen absorption reaction. Surprisingly, iodide and bromide, which had been neglected at all, are surprisingly enough oxygen to store low moisture content packaged items (substances to be preserved) with little water content, with almost no need for water retention components. It has been found that it can function as a promoter of absorption reaction.

The above-mentioned Japanese Patent Publication No. 56-33980 discloses
Although iodide and bromide are listed as one of the oxygen absorption reaction accelerators, they have an oxidation accelerator mainly composed of a metal salt of iodine or bromine, and are suitable for storage of contents with low water activity. No oxygen agent is disclosed.

Japanese Patent Publication No. 2-22701 discloses an oxygen scavenger which is composed of a halide of a basic anion exchange resin and iron powder and which does not require the use of a water-soluble substance, but has a low humidity atmosphere. The purpose of the present invention is not to provide a halide as an oxidation promoter that can function even in a dry state. In fact, a metal salt of iodine or bromine can exert a sufficient catalytic function in a dry state. There is no consideration.

That is, an object of the present invention is to provide a deoxidizing resin composition capable of exhibiting a sufficient deoxidizing function even in a low humidity atmosphere. Another object of the present invention is to provide a deoxidizing resin composition having good thermoformability.

Another object of the present invention is to provide a sheet-shaped or film-shaped oxygen absorber, a packaging material, and a packaging container which can exhibit a sufficient oxygen removal function in a low humidity atmosphere. is there.

Still another object of the present invention is to provide a package for storing an article containing a low water content, which requires a storage condition of a low humidity, in an atmosphere of low oxygen concentration. Still another object is to provide a method for storing a low moisture content article, which can hold the low moisture content article in a low oxygen concentration atmosphere by using the deoxidizing resin composition.

[0017]

DISCLOSURE OF THE INVENTION The present invention provides a deoxidizing resin composition in which a deoxidizing agent containing a reducing metal and an accelerator mainly containing a metal salt of iodine or bromine is kneaded or dispersed in a thermoplastic resin. Is characterized in that. By molding and processing this resin composition, the shape of sheet-shaped or film-shaped packaging material (deoxidizer) having a water content of 1% or less, trays such as packaging containers, cups, tubes, bags, etc. is restricted. A packaging material comprising a molded body that does not stick to the surface can be obtained.

This deoxidized body is obtained by coating and packaging with an oxygen-permeable breathable packaging material. The present invention also provides a multilayer body having an outer layer having a gas barrier property on the atmosphere side of an intermediate layer composed of an oxygen scavenger composition, and an inner layer having gas permeability facing the inner side of the object to be packaged. Characterize. The packaging container is composed of this multilayer body. As long as the desired effect can be achieved, it suffices to provide this multilayer body in a part of the container.
The multilayer packaging material is molded into, for example, a sheet shape or a film shape. The present invention further has a low water content using this packaging material and a packaging container, a method for hermetically storing a preserved material having a low water activity in a low humidity atmosphere, and
A feature of the present invention is that the deoxidized body is a package in which a material to be preserved in a dry state is sealed and stored in an atmosphere of low humidity and low oxygen concentration.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in more detail. In addition, as a known component and its content in the resin composition of the present invention, and a production method, known conventional examples are referred to. For example, the above-mentioned Japanese Patent Publication No. 56-33980 filed in the past by the applicant of the present application can be referred to.

As the reducing metal, known materials can be used as the oxygen absorbing component or the deoxidizing component.
Preferred is metallic iron. Specifically, for example, metal powder such as granular iron powder, copper powder, zinc powder, etc., and preferably iron powder. These are used alone or in combination.
The reducing metal has an average particle size of 100 μm or less, preferably 50 μm or less, in order to make good contact with oxygen. As the metal powder, reducing powder, electrolytic powder, spray powder and the like are preferable.

For example, reduced iron powder, electrolytic iron powder, and atomized iron powder are preferable. In addition, crushed or ground products such as cast iron are used. The average particle size of the metal powder is 1 to 50 μm because the metal powder having a too small particle size has problems such as ignition in handling and is expensive.

Examples of the metal salt of iodide or bromide as the electrolyte halide include electrolytic metal salts, alkali metal salts, alkaline earth metal salts, copper, zinc, aluminum, tin, iron, cobalt, There is a metal salt such as nickel, or a combination of one or more of these. For example, sodium bromide, potassium bromide, sodium iodide, potassium iodide, cadmium iodide, and mercury iodide. Iodide is preferred because of its excellent oxygen absorption at low humidity. On the other hand, bromide is preferable from the viewpoint of food safety.

From the viewpoint of avoiding the use of heavy metals, sodium iodide, potassium iodide, or a combination thereof is preferable. As the bromide, sodium bromide and potassium bromide are preferable.

The reaction accelerator (activator) is mainly composed of iodide and bromide. Here, the term “main body” is relatively defined, and in short, even if the resin composition has a low water content, it does not interfere with the achievement of the deoxygenation reaction, as long as other halides, etc. It does not impede the intervention. In a preferred embodiment, the content of iodide or bromide in the reaction accelerator is 90% by weight or more. It is preferably at least 95%.

The reaction accelerator of the present invention may be mixed with reducing metal powder, but is preferably coated with metal powder.
The content of the reaction accelerator in the oxygen scavenger may be within a known range. For example, the coating amount of the reaction accelerator is 0.1 parts by weight of iodide or bromide with respect to 100 parts by weight of the reducing metal.
To 20 parts by weight. When the reaction active component adheres to the surface of the metal and the metal and iodide do not separate when the oxygen scavenger is mixed with the resin, and the catalytic reaction can be sufficiently expected, it is possible to obtain 0.1% iodide or the like. It may be 10 to 10 parts by weight, and more preferably 0.5 to 6 parts by weight.

The thermoplastic resin to which the oxygen scavenger is added is not particularly limited as long as it is oxygen permeable. Preferably, the oxygen permeability coefficient is 200 cc · 0.1 mm / m ² · atm ·
It is more than a day (23 °, 100% RH). In particular, polyethylene, polypropylene, various ethylene copolymers, modified polyolefins, elastomers and the like are used alone or as a blend. Among these, it is determined in consideration of the adhesiveness with an outer layer and an inner layer having a gas barrier property described later.

Since the deoxidizing resin composition of the present invention is suitable for storing an object to be preserved having a low water content, when it is formed into a sheet or the like, the deoxidizing resin composition itself substantially contains a water retention component. Preferably, the water content is not more than 1% by weight, preferably 0.2%, and in this state because the thermoformability is good without causing problems such as foaming during thermoforming. Can sufficiently achieve the deoxidation reaction.

This upper limit of water content is normally achieved by the heat (heating above the melting temperature of the resin) applied when the oxygen absorber of the present invention is blended with a thermoplastic resin to form a sheet or the like. It

When kneading the thermoplastic resin and the oxygen absorber,
The water content of the oxygen scavenger is 1% by weight, for example 0.1% by weight or less, based on the thermoplastic resin and the oxygen scavenger. It is not always necessary to retain more water in order to exert deoxidizing performance. By doing so, when a resin sheet is made from the resin composition, it is possible to prevent water from remaining in the sheet and generation of bubble-like defects in the sheet.

The oxygen scavenger includes alkaline earth metals and other water absorbing agents (diatomaceous earth, pulp, water-absorbing polymer, etc.), odor adsorbents (activated carbon, molecular sieves, etc.) in order to remove water content. Coloring pigments (titanium oxide, iron oxide,
It does not prevent the inclusion of carbon black, etc.). The resin layer containing the oxygen scavenger may be made to have stretched porosity for the purpose of improving air permeability after the oxygen scavenger is dispersed in the resin.

The outer layer having a gas barrier property is appropriately determined according to the production method and intended use of the intended packaging material. That is, in the sheet produced by co-extrusion and its molded products (tray, cup), etc., ethylene-vinyl alcohol copolymer or nylon MXD6 (manufactured by Mitsubishi Gas Chemical Co., Ltd.)
Is preferably used as a co-extrusion material for forming the outer layer. When a film or the like is obtained by laminating, a polyvinylidene chloride coating, aluminum oxide, oxidation It is preferable to use a polyester or nylon film, a metal foil such as aluminum, or a metal sheet on which a metal oxide such as silicon is deposited. In particular, since the items to be preserved are of low moisture content,
Considering that it is necessary to avoid water vapor transmission as much as possible, it is possible to select a metal sheet or a metal foil.

As the inner layer, in addition to the resin forming the intermediate layer containing the oxygen scavenger, polymethylpentene, polystyrene,
Ethylene-vinyl acetate copolymers and mixtures thereof can be used. That is, polyolefins such as polyethylene, polypropylene, various ethylene-α-olefin copolymers, ethylene acid copolymers, ionomers, polybutenes and polymethylpentenes can be used alone or in combination. Further, a commercially available sealant resin having an easy peeling property can also be used. Further, these resins may be extruded from pellets or may be pasted into a film in advance.

Some commercially available sealant films have a multi-layered structure in order to have an easy peel property, but it is also possible to use this. In addition, a coloring pigment or filler can be added to the resin of this layer to the extent that the properties expected of this layer are not impaired.

This layer can be adhered to the intermediate layer without providing an adhesive layer so as not to prevent oxygen from reaching the intermediate layer from the system to which the substance to be preserved belongs. A material capable of obtaining an appropriate heat-sealing property during bag making and sealing is appropriately selected.

The thickness of this layer is appropriately selected depending on the total thickness of the container, film, etc. in the final form. In the case of a container, the inner layer is 30 to 100 μm, and the intermediate layers 50 to 20.
0 μm, a gas barrier layer of 10 to 50 μm and a polyolefin layer of 100 to 1000 μm for maintaining strength (in the case of a film, an inner layer of 15 to 30 μm,
Intermediate layer 30 to 100 μm, gas barrier layer 5 to 5
0 μm configuration) can be exemplified.

The following can be mentioned as the form of the packaging material and the form of the package of the present invention. A multi-layer film including an inner layer, an intermediate layer, and an outer layer is heat-sealed to form a bag, and the object to be stored is contained in the bag. When heavy packaging is desired, the package may be packaged using kraft paper, a cardboard box, a fiber drum, or a metal can. In addition, a multi-layer sheet consisting of these layers is stored in a multi-layer container (tray, cup, bottle, etc.) that is thicker than the film and made of a material with high rigidity, and these are covered with a gas barrier lid. Cover and seal.

In the present invention, a low moisture content package is a substance having a low moisture content and a small amount of moisture to be diffused so that conventional self-reactive oxygen scavengers cannot be applied, and the water activity (a _w , "AW" may be displayed.) Is preferably 0.2 to 0.7, more preferably 0.2 to 0.5, or water content is 10% or less, or 50% or less, preferably Means RH 50% or less, particularly preferably RH 30% or less. In other words, the method of the present invention is suitably applied to an article having low water activity and requiring storage under dry conditions with low humidity. In order to store low moisture content articles that require low humidity storage conditions, the relative humidity (RH) of the atmosphere in which the low moisture content articles are stored is preferably 20 to 70%, more preferably 20 to 50%. is there. The water content of the low water content article is preferably 50% by weight or less, more preferably 10% by weight.
All of those with weight% or less are applicable, but especially powders and granular foods as low moisture content articles (packages) to which the present invention can be applied: (powdered soup, powdered beverage, powdered confectionery, seasoning, grain flour, nutrition Foods, health foods, colorings, flavors, spices), powders, granules: (powder, powder soap, toothpaste, industrial chemicals), molded products (tablet type) of these things, etc. Examples are foods and medicines that need to be prevented from being mixed.

Examples of the packaging material of the present invention are as follows. In addition, each abbreviation means the following.

PET: Polyethylene terephthalate PE: Polyethylene OA: Oxygen scavenger LLDPE: Linear low-density polyethylene EVOH: Ethylene-vinyl alcohol copolymer PP: Polypropylene exemplifying packaging material Light wrapping paper: Paper (Mataha PET) / Aluminum / PE / PE + OA / PE (LLDPE) Heavy wrapping paper: Paper (2 to 3 layers) / PP / Aluminum / PE / PE + OA / PE (LLDPE) Heavy wrapping box: (tier ball) Box + (PE / PE / EVOH / PE / PE / PE + OA / PE) Container: (PP / EVOH / PP) Container + (PET / Aluminum / PE / PE + OA / PE) Lid Container: (PP / EVOH / PP + OA / PP) Container + (PET / Aluminum / PP) Lid Container: (Aluminum / PP + OA / PP) Container + (PET / Aluminum / PP) Lid

[0040]

[Example] Using a closed ribbon mixer with a heating jacket, reduced iron powder having an average particle size of 30 μm (metal iron content 95
% Or more) to 200 kg, 5 kg of potassium iodide was added and mixed with an aqueous solution, and then steam was passed through the jacket to dry while degassing the inside of the mixer with a vacuum pump to coat the metallic iron surface with potassium iodide, An oxygen absorbing composition was obtained.

Next, using a twin-screw extruder, the oxygen absorbing resin composition, polyethylene, white pigment, and calcium oxide were kneaded in a weight ratio of 50: 45: 5: 0.1, extruded, and then cooled, It was crushed to obtain a resin composition 1.

This resin composition 1 and polyethylene containing 10% of white pigment were laminated in this order on a polyethylene film using a tandem laminator, and then polyethylene terephthalate (PET) was further formed on the polyethylene film side.
And the aluminum foil side are polyethylene extruded and laminated, and as shown in FIG. 1, PET layer (12 μm) (1) / aluminum foil layer (outer layer: 9 μm) (2) / polyethylene layer (20 μm)
m) (3) / deoxidized resin layer (inner layer: 60 μm) (4) /
A multilayer film of polyethylene (inner layer: 25 μm) (5) was obtained. Iron particles having a surface coated with potassium iodide are dispersed in the deoxidizing resin layer.

This film was made into a 130 mm × 140 mm four-side sealed bag. Hereinafter, this bag will be referred to as the "invention packaging bag".
Called. By the same procedure except that the same amount of sodium chloride was used instead of potassium iodide, 130 mm x 1
A 40 mm 4-sided seal was made into a bag. Hereinafter, this bag is referred to as "comparative packaging bag 1." A 130 mm × 140 mm four-side sealed bag was manufactured by the same operation except that the same amount of calcium chloride was used instead of potassium iodide. Hereinafter, this bag is referred to as “comparative packaging bag 2”. On the other hand, a commercially available PET / aluminum foil / polyethylene laminated film was used to make a bag in the same manner. Hereinafter, this bag is referred to as a "gas barrier bag".

When the water content of this resin composition 1 was measured by the Karl Fischer method, it was 500 ppm or less. When the moisture contents of the present invention packaging bag, the comparative packaging bag 1, the comparative packaging bag 2 and the gas barrier bag are measured by the same method,
It was 2000 to 3000 ppm.

Measurement of oxygen absorption capacity of each bag 20 g of diatomaceous earth impregnated with 10 cc of water / glycerin humidity control liquid having the following mixing ratio was put in each bag, and after 40 cc of air was enclosed, the bag mouth was closed by heat sealing. These were stored at 25 ° C. or lower, and the oxygen concentration in the bag after the passage of time was analyzed using gas chromatography. The results are shown in Table 1.

(Mixing ratio of water / glycerin humidity control liquid) RH 100%: 100 parts by weight of water to glycerin 0 RH 50%: 21 parts by weight of water to 79 parts of glycerin RH 30%: 8 parts by weight of water to 92 parts by weight of glycerin

[0047]

[Table 1]

The comparative packaging bag using sodium chloride and calcium chloride as the accelerator has a high oxygen absorption rate under high moisture and high humidity, but has an overwhelmingly excellent oxygen absorbing ability of the present invention under low moisture humidity. I was able to confirm that

Storage Result Test Each of the above-mentioned bags has 50 pieces of matcha, sprinkle, granule soup stock, hot cake mix, ascorbic acid powder, and silicon nitride.
g was filled with 30 cc of air, sealed by heat sealing, and stored at room temperature. FIG. 2 is a schematic view showing a state in which these contents are sealed in the packaging bag of the present invention. The conventional gas barrier bag has only A) ratio storage bag,
B) Water-dependent oxygen scavenger (Ageless F manufactured by Mitsubishi Gas Chemical Co., Ltd.
X-20) enclosed, C) self-reactive oxygen scavenger (ageless Z-20PT) enclosed by three methods.
One month after storage, the oxygen concentration in the bag was analyzed by gas chromatography, and then each package was opened to evaluate the contents. Table 2 shows the results.

[0050] Incidentally, contents which are enclosed in each bag, water, a _w is as follows: a water content less dry food or powders contained. Moisture, 105 ° C. × 2 hours drying loss method, a _w was determined by Shibaura Electric Ltd. aw meter.

Matcha: water content 10% or less, a _w 0.4 sprinkle: water content 10% or less, a _w 0.25 granule soup base: water content 10% or less, a _w 0.35 hot cake mix: water content 10% or less , A _w 0.5 ascorbic acid powder: water content 10% or less, a _w 0.4 silicon nitride: water content 10% or less, a _w 0.4 As shown in Table 2, the packaging bag of the present invention is The stored product also exhibited a good ability to absorb oxygen in the bag. In the comparative packaging bags 1 and 2, the oxygen absorber does not have a moisture donor, so that the oxygen absorption reaction cannot be catalyzed in a low moisture environment, and oxygen is not sufficiently absorbed. Since the gas barrier bag A) does not contain an oxygen scavenger, it is naturally impossible to remove oxygen in the bag. Since the oxygen scavenger in the gas barrier bag B) is a reactive type that causes a deoxygenation reaction by the water that migrates from the outside, the oxygen scavenging reaction does not occur in an environment that contains a dried object to be preserved in which this water cannot be expected. Cannot be achieved properly. Therefore,
Other than the packaging bag of the present invention, deterioration of the contents due to oxygen such as deterioration of flavor and discoloration occurs.

[0052]

[Table 2]

On the other hand, in the gas barrier bag C) containing the self-reactive oxygen scavenger having the water-retaining component itself, the water from the water-retaining component migrates to the food, causing solidification of the powder. In the case of silicon nitride, which is a ceramic material,
In the packaging bag of the present invention, oxidative deterioration and changes in physical properties are prevented, whereas in the case of insufficient oxygen absorption, strength deterioration after sintering is observed due to oxidative deterioration, and a self-reactive oxygen scavenger is used. The molded product showed a decrease in moldability due to the change in physical properties, which is considered to be due to the migration of water.

[0054]

As described above, according to the present invention,
Provided is a deoxidized resin composition capable of sufficiently achieving an oxygen absorption reaction even in a low moisture environment. Therefore, according to the packaging material obtained from this resin composition, it is possible to reliably store the preserved object such as dried foods in a low oxygen environment such as powdered food without degrading quality or property. can do. Moreover, since moisture from the packaging material does not migrate to the preserved object, it is possible to avoid deterioration such as solidification of the preserved object. In addition, the resin composition of the present invention is a novel self-reactive deoxidizing resin composition that does not require the coexistence of a water retainer.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a multilayer film according to the present invention.

FIG. 2 is a schematic view showing a state in which a material to be stored is included in the multilayer film of FIG.

Continued on the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location C08L 101/00 C08L 101/00

Claims (11)

[Claims] 1. A deoxidizing resin composition obtained by kneading a deoxidizing agent with a thermoplastic resin, wherein the deoxidizing agent comprises a reducing metal and an accelerator containing at least one of iodide and bromide as a main component. A deoxidizing resin composition comprising: 2. The iodide is a metal salt of iodine,
The deoxidizing resin composition according to claim 1, wherein the bromide is a metal salt of bromine. 3. The metal salt is an alkali metal salt.
The oxygen absorbing resin composition according to claim 2. 4. The resin composition according to claim 3, wherein the alkali metal salt is at least one of a potassium salt and a sodium salt. 5. The oxygen content of the oxygen absorber is 2000 p.
The resin composition according to claim 1, which has a pm or less. 6. A deoxidizing resin composition obtained by kneading a deoxidizing agent with a thermoplastic resin, wherein the deoxidizing agent is a promoter containing a special reducing metal and at least one of iodide and bromide as main components. The oxygen-absorbing resin composition is characterized in that the oxygen-absorbing resin composition is placed in an environment for storing an object to be packaged having a low water content, and the oxygen concentration in the environment is kept low. Stuff. 7. A sheet-like packaging material obtained by molding the deoxidizing resin composition according to claim 1, and having a water content of 1% by weight or less. 8. An outer layer having a gas barrier property facing the atmosphere side, an intermediate layer made of the resin composition according to any one of claims 1 to 6, and an inner layer for isolating the intermediate layer from an object to be preserved. A multi-layer packaging material. 9. The multi-layer packaging material according to claim 8, wherein the whole is formed into a sheet shape. 10. A package in which an object to be preserved to be kept in a dry state is accommodated inside the packaging material according to any one of claims 7 to 9. 11. A packaging material according to any one of claims 7 to 9, wherein a material to be preserved to be kept in a dry state is housed inside, and then the packaging material is used to store the material to be preserved. How to save.