JPH11347400A - Deoxidizing agent package body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable application in a wide range of humidities by partially or wholly coating with a gas-permeable packaging material powdery or granular deoxidizing constituent having a particular average particle size, and prepared by partially crosslinking a diene polymer or the like having particular C-C unsaturated bond and crosslinkage. SOLUTION: This deoxidizing agent package body is prepared by coating partially or wholly with a gas-permeable packaging material 2 a powdery or granular deoxidizing constituent 1 having an average particle size of 0.01-5 mm, comprising a crosslinked polymer prepared by partially crosslinking a diene polymer or a copolymer of a diene with another unsaturated compound, having 0.0001-0.025 mol of C-C unsaturated bond and 0.0001-0.02 mol of crosslinkage per gram of crosslinked polymer molecule. The crosslinked polymer is preferred to have a flexural modulus of elasticity of 0.1 Mpa or higher at 25 deg.C, a flexural strength of 100 Mpa or lower and a linear expansion of 50% or lower when being swollen by immersion in toluene for one day.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen-absorbing agent package having excellent oxygen-absorbing performance and usable in a wide humidity range from a dry state to a high humidity state. The package oxygen absorber of the present invention is used for the purpose of preventing the oxidation of various articles which are susceptible to deterioration under the influence of oxygen, such as foods, pharmaceuticals, metal products and electronic products, and enabling long-term storage. Is done.

[0002]

2. Description of the Related Art For the purpose of preventing the oxidation of various articles, such as foods, pharmaceuticals, metal products and electronic products, which are susceptible to deterioration under the influence of oxygen, oxygen contained in a packaging container or a packaging bag containing them is used. Deoxidizers for removal have been used in the past. A form initially developed and still widely used as this oxygen absorber is a small bag type containing a powdery or granular oxygen absorber in a packaging material (JP-B-56-5061).
8, Japanese Patent Publication No. 62-6846). Further, as a shape of a single-layer or multi-layer sheet including a layer made of a resin into which a deoxygenating component is kneaded, there is a form in which a small piece of the sheet is put into a packaging material to be a label type, a card type, a packing type, and the like. (For example, JP-A-7-219430 and JP-A-7-137759).

At present, iron powder is most frequently used as a deoxidizing component. However, in order to oxidize metal powder such as iron powder, moisture is required, and if the system to be deoxidized has a small amount of moisture (hereinafter referred to as a drying system), is there any possibility that deoxidation will occur? Or the speed was very low. On the other hand, the present inventors have previously proposed a powdery or granular deoxygenation component which can be used not only in a high-humidity system but also in a drying system, and all of which are solid and easy to handle (Japanese Patent Application No. Hei 10-284,837). 9-174
348). This deoxygenation component is obtained by introducing an appropriate cross-linking structure into an organic compound having a carbon-carbon unsaturated bond, and simultaneously obtaining excellent deoxygenation performance by increasing the surface area as a powder or a granule. . As described above, a new oxygen-absorbing component could be obtained, but in the form of powder or granules, it could not be used for various articles such as foods. I needed to.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, to provide excellent deoxidation performance, to be used in a wide humidity range from a dry state to a high humidity state, and to contact various articles. Another object of the present invention is to provide an oxygen absorber package having no problem.

[0005]

Means for Solving the Problems As a result of intensive studies, the inventors have found that by coating a deoxygenating component comprising a crosslinked polymer having a carbon-carbon unsaturated bond with a gas-permeable packaging material, various types of materials can be obtained. The present inventors have found that the oxygen-absorbing agent package is suitable for preserving dry articles without any problem even when brought into contact with the articles, thereby completing the present invention.

[0006] The present invention relates to a method for producing a polymer comprising 0.00 g of a crosslinked polymer.
1 to 0.025 mol of carbon-carbon unsaturated bonds and 0.00
An average particle size of a crosslinked polymer partially crosslinked from a diene polymer or a copolymer of a diene and another unsaturated compound, having a crosslinking point of from 0.01 to 0.02 mol, having an average particle size of 0.01 to 5
The present invention relates to an oxygen-absorbing agent package in which a powdery or granular oxygen-absorbing component having a thickness of mm is partially or entirely covered with a gas-permeable packaging material. In addition, the present invention provides a method for producing a polymer comprising:
5 mol of carbon-carbon unsaturated bonds and 0.0001 to 0.0
A powdery or granular material having an average particle size of 0.01 to 5 mm, comprising a crosslinked polymer partially crosslinked with a diene polymer or a copolymer of a diene and another unsaturated compound containing 2 mol of crosslinking points; The oxygen-absorbing component is dispersed in a thermoplastic resin and then molded into a sheet or film, and a small or small piece of the sheet or film is partially or entirely covered with a gas-permeable packaging material. . Also, the present invention provides a crosslinked polymer 1 g
Per part of a diene polymer or a copolymer of diene and another unsaturated compound containing 0.001 to 0.025 mol of carbon-carbon unsaturated bonds and 0.0001 to 0.02 mol of crosslinking points per molecule. A powdery or granular deoxygenating component having an average particle size of 0.01 to 5 mm composed of a crosslinked crosslinked polymer is dispersed in a thermoplastic resin, then molded into a sheet or film, and stretched to obtain a continuous microporous material. TECHNICAL FIELD The present invention relates to an oxygen-absorbing agent package obtained by partially or entirely covering small pieces of a formed sheet or film with a gas-permeable packaging material. In addition, the present invention relates to a label-type oxygen-absorbing agent package obtained by imparting adhesiveness to a part of the surface of the packaging material of the oxygen-absorbing agent package. In addition, the present invention relates to a card-type oxygen absorber package using a strong base material as a part of the packaging material of the oxygen absorber package. The present invention also relates to a packing type oxygen absorber package using a flexible base material as a part of the oxygen absorber package of the oxygen absorber package.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The crosslinked polymer in the present invention is
Polymers of diene or copolymers of diene and other unsaturated compounds containing from 0.001 to 0.025 mol of carbon-carbon unsaturated bonds and from 0.0001 to 0.02 mol of crosslinking points per gram of crosslinked polymer. A high molecular compound obtained by partially cross-linking a polymer.

The term “crosslink” in the present invention refers to a crosslink consisting of a covalent bond. In this case, various covalent bonds can be used, but in order to impart heat resistance to the crosslinked polymer, C-C, C-
A crosslinked structure by a bond having a high binding energy such as -O or CN is desirable. By introducing such a crosslinked structure, the molecules become large and become insoluble or infusible, so that they become easy-to-handle deoxygenating components and their application range is expanded. In addition, since a carrier or the like is not required, the amount of oxygen absorbed per unit weight increases.

Various methods known in polymer chemistry can be used for producing the crosslinked polymer in the present invention. For example, a crosslinked polymer can be obtained by directly polymerizing a single or plural types of monomers having a relatively small molecular weight (including some of which have three or more functional groups, and having a total average functional group of more than 2). Alternatively, a crosslinked polymer may be obtained by later crosslinking an oligomer or polymer having a relatively large molecular weight. Of these, the latter method, which generates less heat of polymerization and is suitable for mass production, is suitable. As a method for performing crosslinking later, it is possible to use ordinary physical or chemical means. Physical crosslinking methods include simple high-temperature heating, irradiation with electromagnetic waves (ultraviolet rays, γ rays, microwaves, etc.), particle beams (electrons, etc.), and ultrasonic waves. Chemical crosslinking methods include And a method using a reaction using various radical generators known as an initiator or a crosslinking agent. Among these, a method by a crosslinking reaction using an organic peroxide as a radical generator is the simplest. In addition, if it is taken into consideration to prevent the low molecular compound derived from the radical generator from remaining in the crosslinked polymer, the crosslinking may be performed by electron beam irradiation, discharge in the presence of oxygen, or the like. A specific method for producing a powdery or granular crosslinked polymer using chemical crosslinking is as follows. That is, first, the mixture of the organic compound (substance to be crosslinked) and the radical generator before crosslinking is crosslinked in a lump state, crosslinked in a solution state, crosslinked in a suspension state or an emulsified state, or the like. I do. Then, in order to make a powdery or granular solid, pulverization in the case of crosslinking in a lump state, drying and pulverization in the case of crosslinking in a solution state, and liquid phase in the case of crosslinking in a suspension state or an emulsification state. Separate and dry.
For each of these unit operations, many techniques and devices known from chemical engineering can be used.

The crosslinked polymer in the present invention is in the form of powder or granules having an average particle size of 0.01 to 5 mm, and a preferable range of the particle size is 0.03 to 0.5 mm. If the particle size is too large, the oxygen absorption rate becomes too low, and if the particle size is too small, there is a danger such as dust explosion. In the present invention, a powdery or granular crosslinked polymer having an average particle size of 0.01 to 5 mm is used as a deoxidizing component.

The degree of cross-linking in the cross-linked polymer in the present invention must be set within such a range that powder or granules can be easily obtained and at the same time, appropriate heat resistance and oxygen absorption performance can be obtained. The appropriate degree of crosslinking varies depending on the molecular structure and molecular weight of the object to be crosslinked, but includes 0.0001 to 0.02 mol of crosslinking points per gram of the crosslinked polymer. As a result, for example, in the case of pulverization after cross-linking in a lump state, the plasticity of the cross-linked polymer is reduced due to appropriate cross-linking, and the cross-linked polymer becomes brittle to facilitate pulverization.

As a change in physical properties due to crosslinking, the crosslinked polymer of the present invention has a flexural modulus at 25 ° C. of 0.1.
It is preferably at least MPa, more preferably at least 1 MPa, even more preferably at least 10 MPa. Further, the crosslinked polymer in the present invention preferably has a bending strength (breaking strength) at 25 ° C. of at least 100 MPa or less, more preferably 10 MPa or less. Further, the crosslinked polymer in the present invention preferably has a linear expansion (increase in one direction) of 50% or less after immersion in toluene at 25 ° C. for one day.

With respect to the relationship between heat resistance and degree of crosslinking, when powder or granules are used as an oxygen scavenger, they are kneaded in a resin up to 100 ° C. or higher, preferably 150 ° C. or higher, and used in various forms. In some cases, the crosslinking is carried out up to 150 ° C. or more, preferably up to 200 ° C. or more so as not to flow or adhere to each other. Thereby, the deoxidizing component can be kept in a solid state in each use form, and can be used as a deoxidizing agent as in the case of iron powder.

In relation to the oxygen absorption performance and the degree of crosslinking,
When an organic compound containing a carbon-carbon unsaturated bond is used for the object to be crosslinked, the same bond (precisely, the carbon having the same bond and the carbon adjacent thereto) mainly participates in the crosslinking, but the same bond reacts with oxygen. Therefore, it is necessary to leave the bond appropriately. Specifically, an organic compound containing a plurality of carbon-carbon unsaturated bonds in one molecule is used, cross-linking is performed using only a part of the bonds, and 0.001 to 0.025 m / g after cross-linking.
leaving a carbon-carbon unsaturated bond of ol.

As the deoxidizing component of the present invention, various metals or metal compounds known in the autoxidation of ordinary organic compounds are added to the crosslinked polymer as a catalyst, and the oxidation reaction of the deoxidizing component is not added. It is preferable to promote it more than the case. However, even if the particle size is reduced, the reactivity is increased. Therefore, if the particle size is sufficiently reduced, an appropriate oxidation rate can be obtained without adding this catalyst. Also, in general, the smaller the particle size, the less the catalyst may be. Further, when various polymers are used as the object to be crosslinked, there is a possibility that an effective oxidation catalyst may be obtained with only a small amount of the remaining polymerization catalyst. The metal used in the catalyst or the metal species in the metal compound is not particularly limited, but a transition metal is particularly desirable because its electronic state is for a catalyst. Of these metal species, cobalt is known to exhibit particularly high catalytic activity, and iron and manganese are known to be relatively safe. The catalyst is mixed with the object to be cross-linked before cross-linking, particularly in the case of chemical cross-linking, with the object to be cross-linked and a radical generator. As a result, the catalyst is uniformly dispersed or dissolved, and is uniformly contained even after crosslinking.
Here, it is desirable to use a catalyst having high solubility in the organic compound to be crosslinked so that the catalyst can be more uniformly dispersed or dissolved. Specific examples include metal fatty acid salts. In that case, if the fatty acid portion contains a carbon-carbon unsaturated bond, it can be incorporated into a crosslinked polymer. Since the catalyst in the deoxygenated component is taken into the crosslinked structure, the catalyst rarely leaks from the deoxygenated component. As a result, even when the deoxygenated component is kneaded and used in a thermoplastic resin serving as a matrix component, the catalyst is unlikely to leak out of the deoxygenated component, so that deterioration due to oxidation of the matrix component is minimized. In the deoxidizing component of the present invention, the oxidation reaction is also promoted by irradiation with light (mainly in the ultraviolet region), as is also known in autoxidation. However, irradiation of light is not essential because the powder or the particles are small, and when a catalyst is further added, the catalyst also acts.

In the deoxidizing component of the present invention, especially when the amount of the catalyst is small, the initial oxygen absorption rate after being left in an oxygen atmosphere is low, and an induction period occurs. This is also desirable because it allows more time to produce the form of the oxygen scavenger of the present invention. However, if the induction period is too long, so as to start oxygen absorption in a short time after starting to use as a deoxidizer, for example, during the induction period in advance,
A treatment such as leaving the substrate in an oxygen atmosphere may be performed.

As the object to be crosslinked, a compound containing a carbon-carbon unsaturated bond is used. As the compound having a large number of carbon-carbon unsaturated bonds contained per unit weight, a polymer (oligomer, polymer or copolymer) of a diene compound is preferable, and specific examples thereof include polybutadiene and polyisoprene. In the polymer of the diene compound,
Antioxidants are often added. It is desirable that such an antioxidant is not contained because it prevents deoxidation after cross-linking to form a deoxygenated product. It can also be activated.

In the deoxidizing component according to the present invention, the crosslinked polymer itself is easily charged due to its low polarity, and particularly when it is made into fine powder, adhesion to the surroundings becomes remarkable and handling becomes difficult. Therefore, in order to prevent this charging, it is desirable to add a compound having a relatively high polarity. Such compounds are generally known as antistatic agents, and those which are also recognized as food additives are particularly desirable from the viewpoint of safety. Further, in the deoxidizing component according to the present invention, it is desirable to add such a compound before crosslinking and incorporate it into the crosslinked structure.

The safety against accidental eating of the deoxygenated component according to the present invention is extremely high. This is because, as a crosslinked product, the solubility of the powder or the whole as a whole is extremely low, and the elution of the low-molecular compound or the metal of the catalyst generated by the oxidation from the individual powder or the particle is extremely small. That's why.

In general, in the case of a deoxygenated component containing an organic compound as a main component, a low-molecular-weight compound that emits odor is generated along with the oxidation reaction. However, the crosslinked polymer in the present invention has a low internal bond, so that a low-molecular compound is hardly generated, and further, the release (volatilization and elution) of the low-molecular compound out of the powder or the particles is small. In addition, since the volume increase during the oxidation reaction is limited by the crosslinked structure, the oxidation reaction does not proceed too much,
The production of low molecular weight compounds is reduced. As a further improvement in odor, first, there is an improvement in the molecular structure of the oxide target.
This corresponds to a structure which is not eliminated as a low molecular compound even if a covalent bond is broken by an oxidation reaction. Specifically, for example, in the case of oligomers or polymers of diene compounds, it is recommended to use a variety having a small number of side chains and a low ratio of 1,2 bonds, and use of polybutadiene rather than polyisoprene. In addition, although the oxygen absorption performance is low, it is also effective to use a copolymer of a diene and an olefin containing a carbon-carbon unsaturated bond loosely, an oligomer of a diene compound or a partially hydrogenated product of a polymer. is there. Also,
In chemical cross-linking, there is a low molecular compound derived from a radical generator, and for this too, a molecule after radical cleavage is selected as large as possible, or similarly as small as possible and removed after cross-linking. Reduces odor generation. On the other hand, as a method of removing the odor that cannot be avoided after oxidation, an adsorbent such as activated carbon may be used together with the deoxidizing component.

The oxygen-absorbing component of the present invention is a main component of the oxygen-absorbing agent.
It can be used together with an adsorption component, an antibacterial component and the like. Moreover, you may use together with another deoxygenation component. When using a relatively large amount of crosslinked polymer to absorb a large amount of oxygen,
If the calorific value at the time of oxygen absorption increases and the heat dissipation is poor, the temperature rise (heat storage) of the crosslinked polymer and the effect on various articles due to the temperature rise cannot be ignored. As a countermeasure, other powders or grains which are thermally stable and do not have a deoxygenation function may be added as an endothermic component in order to keep a plurality of powders or grains apart from each other. For this purpose, various inorganic and organic compounds having a large heat capacity can be used. Among them, a thermoplastic resin having a large heat capacity, which has a melting point around 100 ° C. or lower and is capable of absorbing heat even in a phase change, is particularly desirable.

In order to prevent not only the above-described heat storage, but also the scattering of powder and particles, and the prevention of accidental eating, a deoxidizing component composed of a crosslinked polymer is kneaded and dispersed in a thermoplastic resin to form an integrated resin composition. It can be used in the form of a sheet or the like as an object. In this case, it is also possible to simultaneously knead at least one of the other components, specifically, one of the adsorption component, the dry component, and the antibacterial component. Such thermoplastic resins include ethylene, propylene, 1-butene, 4-methyl-
Many things can be used, such as homopolymers and copolymers of various olefins such as 1-pentene, ethylene-vinyl acetate copolymer, hydrogenated styrene-butadiene copolymer, and the like. Modified products, grafts,
It may be a mixture or the like.

In the resin composition in the form of a sheet or the like, the oxygen-absorbing rate is reduced because the deoxidized component is shielded by the thermoplastic resin. Therefore, it is desirable to increase the oxygen absorption rate by making the sheet or the like continuous microporous by stretching or firing, and directly contacting the deoxygenated component with the surrounding atmosphere through the continuous microporous. In the case of continuous microporosity by stretching, it is necessary to knead the powder or granules of the crosslinked polymer into the thermoplastic resin at a relatively high volume fraction. Its volume fraction is approximately 0.10 to 0.60, more preferably 0.1 to 0.60.
When the volume fraction is lower, the sheet or the like after stretching is not continuously microporous, and when the volume fraction is higher, the sheet or the like becomes brittle after stretching. Here, since the density of the crosslinked polymer and the density of the thermoplastic resin have approximately the same value, the addition ratio of the crosslinked polymer is generally 10 to 60 wt%,
More preferably, it becomes 20 to 40% by weight. When the crosslinked polymer and the other components are kneaded at the same time, the combined volume fraction may be within this range.

The oxygen scavenger package of the present invention may be a powdery or granular oxygen scavenger, a sheet or film oxygen scavenger, or a microporous sheet or film oxygen absorber. Some or all of the components are covered with a breathable packaging material. For example, a bag made entirely of breathable packaging material and sealed with a deoxygenating component, a bag made of a breathable packaging material with a barrier material on the back, And sealed.

As the air-permeable packaging material, various kinds of generally known air-permeable layered materials (resin film, paper, etc.) having a single layer or a multi-layer can be used. Here, if deoxygenation is performed from the gas phase, both a nonporous (those having no through-hole in the total thickness) layered material and a porous layered material can be used. It is desirable to use a porous layered material having a high viscosity. Further, when deoxidizing from a system containing an object having a large amount of liquid, or further, when deoxidizing by immersing a deoxidizer package in a liquid, a nonporous layered material is desirable, and in many cases, Must be a nonporous layered material.

As for the air permeability of the packaging material, it is desirable that the rate of oxygen permeation of this packaging material is higher than the rate of oxygen absorption of the deoxygenated component composed of the crosslinked polymer, and it is more preferable that the rate of permeability is two orders of magnitude or more. As a result, the oxygen permeability of the packaging material does not become rate-determining, and the oxygen absorption rate inherent to the crosslinked polymer as the deoxidizing component can be sufficiently exhibited. The air permeability of the packaging material is 5 × 10 ⁻⁵ [cm ³ / cm ² /
h / Pa] or more. It is generally difficult to achieve such air permeability with a nonporous layered material because the thickness of the layered material is too small. Therefore, a choice is made between using a larger area of the packaging material or allowing the speed to decrease. On the other hand, a porous layered material, particularly a layered material having a through-hole that can be visually confirmed, can easily realize this transmittance.

The packaging material may be a multi-package using a plurality of types of packaging materials in multiple stages, or a highly safe water repellent or oil repellent to impart water resistance or oil resistance. May be impregnated. Further, a label-type oxygen absorbing agent package is formed by adding an adhesive portion to an outer part of the packaging material, and a card-type oxygen absorbing agent using a strong base material as a part of the packaging material. It is possible to form a packing and a packing type oxygen absorber using a flexible base material as a part of the packaging material.

The deoxidizing component of the present invention has few problems even if it is incinerated at the time of disposal after absorbing oxygen, and it can be expected that it is also biologically decomposed. Therefore, if various environmentally conscious materials such as biodegradable resin and paper are used for the thermoplastic resin and the packaging material into which the deoxidizing component is kneaded, the problem of disposal of the entire deoxidizing agent is further reduced. Become. The deoxidizing component of the present invention does not contain a metal element in a metal state. Therefore, the interaction with the electromagnetic wave is weak, the metal detector is not operated, and the microwave is hardly heated even in the microwave oven. These properties are retained in the oxygen absorber package.

The oxygen-absorbing agent package of the present invention can be formed into various known gas barrier containers or packaging bags, such as bags made of resin or other films, resin containers, metal cans, and glass containers. It can be put together with various articles to be deoxidized, sealed, and used for preservation of the various articles.
The amount of the deoxidizing component to be actually used is determined in consideration of the degree of barrier property of the container or the packaging bag, the volume of oxygen in the container or the packaging bag, the time at which the deoxygenation is desired, and the like. In the normal case where the barrier property of the container or the packaging bag is high and the deoxidation time is within several days, 2
It is desirable to use a deoxidizing component capable of absorbing up to about three times as much oxygen. If the barrier property of the container or the packaging bag is low or if it is desired to shorten the deoxidizing time, it is preferable to use a larger amount of the deoxidizing component. desirable. FIG. 1 shows an oxygen-absorbing agent package in which all components including the oxygen-absorbing component are placed in a small bag made of a breathable packaging material. FIG. 2 shows an oxygen-absorbing agent package in which a small piece obtained by kneading all components including a deoxidizing component into a thermoplastic resin and making it microporous is placed in a small bag. FIG. 3 shows a label-type oxygen-absorbing agent package in which the same small piece as in FIG. 2 is placed in a packaging material to which a part having an adhesive property has been added to an outer part thereof. FIG. 4 shows a card-type or packing-type oxygen absorber package in which the same small pieces as those in FIG. 2 are partially placed in a packaging material using a rigid or flexible substrate.

[0030]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The compounds used are as follows. Cross-linked product, butadiene oligomer: manufactured by Nippon Zeon Co., Ltd., trade name Polyoil 130, average molecular weight 3000, 1,4 structure 99
%, Liquid having a viscosity of 3000 cP at 20 ° C., the number of carbon-carbon double bonds is 1/54 =
It is calculated to be 0.0185 mol / g. Organic peroxide, α,
α'-bis (tert-butylperoxy) diisopropylbenzene: manufactured by NOF Corporation, trade name: Perbutyl P, molecular weight: 338, 1
The number of effective functional groups per mol is 2 mol, and the purity is 95%. Catalyst, iron (III) stearate: manufactured by Mitsuwa Chemicals Co., Ltd.
Purity 95% or more. Antistatic component, monoglycerin stearate: manufactured by NOF CORPORATION, trade name: Monogly M, purity: 95% or more. Adsorbent, activated carbon: Shirasagi A, manufactured by Takeda Pharmaceutical Co., Ltd., having a size of 50 μm or more after sieving. Thermoplastic resin, polypropylene: manufactured by Nippon Polychem Co., Ltd., trade name: NOVATEC PP FG3D. The product is classified as polypropylene, but is actually a copolymer containing a small amount of ethylene, and has a melt flow rate of 7.0 g / 10 min (230
° C).

The methods for measuring various properties are as follows. The flexural modulus and flexural strength of the deoxidized component were determined by cutting a test piece (for example, 4 cm x 1 cm x 2 mm) from the crosslinked product before pulverization,
And performed a three-point bending test. At this time, the bending elastic modulus E is given by the following equation when a relatively small deformation is given:
E = FL ³ / 4WT ³ D, and the bending strength S is given by the following equation when deformation is given to failure: S = 3F
With L / 2WT ^2, it was calculated, respectively. here,
F: load, L: span, W: width of test piece, T: thickness of test piece, D: displacement (deflection) (JIS K72)
03 (1995)). The deformation speed was about 10 cm / s. Linear expansion due to swelling of deoxygenated component (ratio of increase)
Is a test piece (about 5 cm in length, 2
mm or less) and immersed in toluene (special grade, about 100 times the volume of the test piece) at 25 ° C for 1 day. Divided by the dimensions of The samples described below were all 6
Swelling equilibrium was reached within hours. The density of the deoxygenated component was measured at 25 ° C. in a pycnometer using ethanol (special grade) as a liquid for sinking the crosslinked product. The degree of cross-linking of the deoxygenated component is obtained by calculating the density ν of cross-linked chains (a partial chain sandwiched between two cross-linking points) by a volume change due to swelling, by the formula: ν = − (v + μv
² + log _e (1-v)) / (ρV _o (v ^1/3 −v /
2)) Estimated by calculating with + 2 / M (Junji Furukawa,
Shinzo Yamashita, Journal of the Rubber Society of Japan, 30,955 (1957)). here,
v: Fraction of volume before swelling to volume after swelling, linear expansion due to swelling (ratio of increase, measured as described above) is α, and v = 1 / (1 + α) ³ , μ: polymer (Here the crosslinked product) and the interaction parameters of the solvent (values for the individual target systems described below are, for example, RGBeaman, J. Poly
mer Sci., 9,470 (1952)), ρ; density of cross-linked product (measured as described above), V _o ; molecular volume of solvent (107 cm ³ / mol in toluene at 25 ° C.), M: cross-linked before cross-linking Molecular weight of the product. From the ν obtained from this, the number of bridge points is ν
Is calculated as 1/2 of The number of carbon-carbon double bonds in the cross-linked product is partially used by the cross-linking reaction (however, in general, not all of the cross-linking reaction components are derived from the same bond). The calculation was performed assuming that the number was obtained by subtracting the number of crosslinking points from the number of bonds. The heat resistance of the deoxygenation component is as follows: Place the powder or granules on a metal plate heated to a predetermined temperature for about 30 seconds (for a long time, there is deformation or discoloration due to oxidation), and observe the flow, deformation or mutual adhesion. Observed and judged. The packaging material has an air permeability of about 2 × 10
^-4 [cm ³ / cm ² / h / Pa] laminated with perforated polyethylene film and paper, adhesive on one side (before attaching to other things, this adhesive side is Polyethylene film with film), about 1mm thick
And a sheet of foamed polyethylene having a thickness of about 0.5 mm was used in combination. The oxygen absorption performance of the oxygen absorber is measured by placing the oxygen absorber of each form and a predetermined amount of air in a transparent oxygen-barrier bag containing a nylon layer coated with polyvinylidene chloride, and measuring the oxygen concentration at 25 ° C. The change over time was tracked by a gas chromatograph. The time required for the oxygen concentration to reach 0.1% by volume was defined as the deoxidation time.
Here, since the change with time of the oxygen concentration monotonously decreases, it is sufficient to express the oxygen absorption performance by this deoxidation time.
The odor was judged sensorially by smelling the gas inside the bag.

Example 1 Butadiene oligomer (Polyoil 130): 93 parts by weight
7 parts by weight of perbutyl P, 1 part by weight of iron (III) stearate, 1 part by weight of monoglycerin stearate; 1 part by weight were uniformly mixed at 60 ° C., and then mixed in a vessel purged with nitrogen.
The mixture was heated at 80 ° C. for 30 minutes to obtain a crosslinked product. After cooling it down to room temperature, take it out, and use a part of it as a sample for measurement.
Others are pulverized by a rotary blade type pulverizer, and the maximum particle size is 300 μm,
A powder having an average particle size of 180 μm was obtained. Because the crosslinked product is brittle,
Grinding was very easy. From various measurements, the flexural modulus of the crosslinked polymer was 2.8 MPa, the flexural strength was 1.0 MPa, the specific gravity was 0.95 g / cm ³ , and the linear expansion due to swelling when immersed in toluene was 32%. Using μ = 0.37, ν = 0.0
The calculated value was 019 mol / g, and the number of crosslinking points was 0.0010 mol / g. The number of carbon-carbon double bonds in the crosslinked product is
0.0185 × (93/102) −0.0010 = 0.
It was calculated as 0159 mol / g. Heat resistance is 150 ° C
That was all. 1 g of this powdery crosslinked polymer and 0.
1 g is put in a bag made of a packaging material in which a perforated polyethylene film and paper are laminated, and the periphery of the packaging material is heat-sealed.
An oxygen absorber package was prepared. The area of the packaging material other than the heat-sealed portion was 40 cm ² . This oxygen absorber package and 300cm
³ air is sealed in an oxygen barrier bag,
Left. The deoxygenation time was 2.9 days. Also, almost no odor was felt.

Example 2 The same powdery crosslinked polymer as in Example 1 was 35% by weight and activated carbon was 2% by weight.
% And polypropylene (FG3D) 63 wt% were heated and mixed at 200 ° C., molded, and cooled to obtain a sheet having a thickness of 2 mm.
This sheet was heated to 120 ° C. and stretched about 6 times in one axis direction to obtain a continuous microporous sheet. The porosity of the sheet after microporous stretching was 0.45, as determined from the dimensional change before and after stretching. From this stretched sheet, an area of 10 cm ²
Were cut out into 5 pieces (about 3 g in total), put together in a bag made of the same packaging material as in Example 1, and heat-sealed the surroundings to prepare a package of oxygen scavenger. When measured in the same manner as in Example 1, the deoxygenation time was 3.1 days.
Also, almost no odor was felt.

Example 3 A packaging material obtained by laminating a perforated polyethylene film and paper and a polyethylene film packaging material having an adhesive on one side were
The two sides of the polyethylene were used to face each other, two small pieces same as those in Example 2 were sandwiched between them, and the periphery of the packaging material was heat-sealed to prepare a label-type oxygen absorber package. The measurement was performed in the same manner as in Example 1 except that the air amount was changed to 100 cm ^3, and the deoxidation time was 3.0 days.
Also, almost no odor was felt.

Example 4 A packaging material obtained by laminating a perforated polyethylene film and paper and a packaging material obtained by laminating a polyethylene film on paper having a thickness of about 1 mm were used so that both polyethylene sides faced each other. After sandwiching the same two small pieces as in Example 2, the periphery of the packaging material was heat-sealed to prepare a card-type oxygen absorber package. When measured in the same manner as in Example 3, the deoxygenation time was 3.0 days. Also, almost no odor was felt.

Example 5 A packaging material in which a perforated polyethylene film and paper were laminated, and a foamed polyethylene sheet having a thickness of about 0.5 mm were used so that the former polyethylene side faced the latter, and was used between them. After sandwiching the same two small pieces as in Example 2, the periphery of the packaging material was heat-sealed to prepare a packing type oxygen-absorbing agent package. When measured in the same manner as in Example 3, the deoxygenation time was 3.0 days. Also, almost no odor was felt.

Comparative Example 1 1 g of the same powdery crosslinked polymer as in Example 1 was put in an oxygen barrier bag together with 300 cm ^{3 of} air without putting it in a packaging material. As a matter of course, the inside of the bag had a little powder attached to the surface, and it was difficult to use the bag together with various articles to be deoxidized.

Comparative Example 2 Calcium chloride (iron powder 1) was added to iron powder having an average particle size of about 50 μm.
(2 parts by weight with respect to 00 parts by weight) was sprayed and dried with an aqueous solution, and as an oxygen-absorbing component, an oxygen-absorbing agent package was prepared in the same manner as in Example 1 except that the crosslinked polymer was used instead. The deoxidation time was measured. Since this deoxidized component did not function in a dry state, it was not deoxidized even after 15 days.

[0039]

The oxygen scavenger package of the present invention can be used in a wide humidity range from a dry state to a high humidity state, and has not only a high oxygen absorption rate but also easy handling. This oxygen scavenger package can be used for the purpose of preventing oxidation of various articles such as foods, medicines, metal products, and electronic products which are easily deteriorated under the influence of oxygen and preserving them for a long period of time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a form in which various components including an oxygen-absorbing component are put into a bag made of a breathable packaging material to form an oxygen-absorbing agent package.

FIG. 2 shows a form in which various components including a deoxidizing component are kneaded into a thermoplastic resin and stretched, and a continuous microporous small piece is placed in a bag made of a breathable packaging material to form a package of an oxygen absorbing agent. Sectional view

FIG. 3 is a breathable packaging material obtained by kneading various components including a deoxygenating component into a thermoplastic resin, stretching the resultant, and then forming a continuous microporous small piece to which an adhesive portion is added to an outer part thereof. Sectional view of the form in which it is put into a container to form a label-type oxygen absorber package

FIG. 4 is a gas-permeable packaging material in which various components including a deoxygenating component are kneaded into a thermoplastic resin, stretched, and continuously made microporous. Sectional view of the form of a card type or packing type oxygen absorber package

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Various components containing a deoxidizing component 2 Wrapping material (single layer or multilayer) made of a gas-permeable film 3 Small components obtained by kneading various components containing a deoxidizing component into a thermoplastic resin and making them microporous 4 Surface of one side ( Here is the sticky packaging material (single or multi-layer) on the lower side of the figure. 5 Strong or flexible substrate (single or multi-layer)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takahiro Seki 6-1-1 Shinjuku, Katsushika-ku, Tokyo Tokyo Research Laboratory Mitsubishi Gas Chemical Co., Ltd.

Claims (9)

[Claims] (1) 0.001 to 0.1 / g / g of crosslinked polymer.
025 mol of carbon-carbon unsaturated bonds and 0.0001 to
A powdery polymer having an average particle size of 0.01 to 5 mm, comprising a crosslinked polymer partially crosslinked with a diene polymer or a copolymer of a diene and another unsaturated compound, containing 0.02 mol of crosslinking points; Alternatively, an oxygen-absorbing agent package obtained by partially or entirely covering a granular oxygen-absorbing component with a gas-permeable packaging material. 2. The amount of 0.001 to 0.1 per g of the crosslinked polymer.
025 mol of carbon-carbon unsaturated bonds and 0.0001 to
A powdery polymer having an average particle size of 0.01 to 5 mm, comprising a crosslinked polymer partially crosslinked with a diene polymer or a copolymer of a diene and another unsaturated compound, containing 0.02 mol of crosslinking points; Alternatively, an oxygen-absorbing agent package obtained by dispersing a granular oxygen-absorbing component in a thermoplastic resin and then forming a sheet or film, and partially or entirely covering a small piece of the sheet or film with a gas-permeable packaging material. body. 3. The amount of 0.001 to 0.1 g / g of the crosslinked polymer.
025 mol of carbon-carbon unsaturated bonds and 0.0001 to
A powdery polymer having an average particle size of 0.01 to 5 mm, comprising a crosslinked polymer partially crosslinked with a diene polymer or a copolymer of a diene and another unsaturated compound, containing 0.02 mol of crosslinking points; Alternatively, a granular deoxygenating component is dispersed in a thermoplastic resin, and then molded into a sheet or film, and a part or all of a small piece of the sheet or film that has been stretched and continuously made microporous is partially or entirely formed of a breathable packaging material. An oxygen scavenger package that is coated. 4. The cross-linked polymer according to claim 1, wherein the cross-linked polymer contains at least one of a metal or a metal compound serving as a catalyst for an oxidation reaction and a compound for preventing electrification. The package for an oxygen scavenger according to item 1. 5. The crosslinked polymer has a flexural modulus at 25 ° C. of 0.1 MPa or more and a flexural strength of 100 MPa or less, and has a linear expansion of 50% after being swelled by immersion in toluene for 1 day.
The oxygen absorber package according to any one of claims 1 to 3, wherein: 6. The air permeability of the packaging material is 5 × 1 in air permeability.
The oxygen-absorbing agent package according to any one of claims 1 to 3, wherein the oxygen-absorbing agent package is at least 0 ^-5 [cm ³ / cm ² / h / Pa]. 7. A label-type oxygen-absorbing agent package obtained by imparting adhesiveness to a part of the surface of the packaging material of the oxygen-absorbing agent package according to claim 1. 8. A card-type oxygen absorber package comprising a solid base material as a part of the packaging material for the oxygen absorber package according to claim 1. 9. A packing-type oxygen absorber package comprising a flexible base material as a part of the packaging material of the oxygen absorber package according to claim 1.