JP2002241608A - Oxygen-absorbing resin composition, packaging material and multi-layered container for package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxygen-absorbing resin composition which has an oxygen barrier property and an oxygen-absorbing property and can reduce the penetration of oxygen through the layer of the resin composition over a long period. SOLUTION: This oxygen-absorbing resin composition is characterized by comprising a polyamide resin, an oxidizing organic component, and a transition metal-based catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen-absorbing resin composition, a packaging material and a packaging container using the same, and more specifically, it can stably suppress oxygen permeation through a vessel wall for a long period of time. The present invention relates to an oxygen-absorbing resin composition.

[0002]

2. Description of the Related Art Conventionally, metal cans, glass bottles, various plastic containers and the like have been used as packaging containers.
Deterioration of contents and reduction in flavor due to oxygen remaining in the container and oxygen permeating the container wall have become problems.

[0003] In particular, in a metal can or a glass bottle, oxygen permeation through the container wall is zero, and only oxygen remaining in the container is a problem, whereas in a plastic container, oxygen permeation through the container wall is zero. It occurs in orders that cannot be ignored and poses a problem in the preservability of the contents.

In order to prevent this, in a plastic container, the container wall has a multilayer structure, and at least one of the layers is made of an oxygen-permeable resin such as an ethylene-vinyl alcohol copolymer. I have.

[0005] An oxygen absorber has been used for a long time to remove oxygen in a container. An example of applying the oxygen absorber to the container wall is disclosed in Japanese Patent Publication No. 62-1824. According to the above, a layer formed by mixing a deoxygenating agent mainly composed of a reducing substance such as iron powder with an oxygen-permeable resin and a layer having an oxygen gas barrier property are laminated to form a multilayer structure for packaging. And

Japanese Patent Application Laid-Open No. 1-278 according to the proposal of the present inventors.
No. 344 discloses that the oxygen permeability coefficient at 20 ° C. and 0% RH is ^10-12 cc · cm / cm ² · sec · cmHg or less and 20
A resin composition obtained by blending an organometallic complex of a transition metal with a gas-barrier thermoplastic resin having a water adsorption of 0.5% or more at 100 ° C. and 100% RH is used as an intermediate layer, and moisture resistance is provided on both sides of the intermediate layer. A plastic multilayer container characterized by a laminated structure provided with a layer of a plastic resin is described.

JP-A-2-500846 discloses a metal-catalyzed oxidation of an oxidizable organic component in a composition comprising a polymer and having oxygen-scavenging properties or a packaging barrier containing a layer of the composition. Describes the use of a barrier for packaging characterized by capturing oxygen by using a polyamide, particularly a xylylene group-containing polyamide as the oxidizable organic component.

[0008]

The method in which an oxygen absorbent such as iron powder is blended with a resin and used for a container wall of a packaging material is satisfactory in that oxygen absorption performance is large. There is a limitation in application that it cannot be used in the field of packaging that requires transparency because of coloring to a specific hue.

On the other hand, an oxygen-absorbing resin composition containing a transition metal catalyst has the advantage that it can be applied to a substantially transparent packaging container. Is deteriorated by oxidation, so that there is a drawback that oxygen permeation through the vessel wall increases with time.

The present inventors have paid attention to the fact that a polyamide resin is itself a resin having excellent oxygen barrier properties, and imparts oxygen absorbability to the resin layer without impairing the oxygen barrier properties. As a result, it has been found that by blending an oxidizing organic component and a transition metal catalyst with a polyamide resin, oxygen permeation through the resin composition can be reduced over a long period of time. That is, an object of the present invention is to provide an oxygen-absorbing resin composition having both an oxygen barrier property and an oxygen-absorbing property and capable of reducing oxygen transmission through a layer of the resin composition for a long period of time. Another object of the present invention is to provide a function-separated oxygen-absorbing resin composition in which a polyamide resin retains excellent oxygen barrier properties and exhibits oxygen-absorbing properties by an oxidizing organic component. Still another object of the present invention is to provide an oxygen-absorbing resin composition which has improved oxygen absorption rate and oxygen absorption capacity, is excellent in transparency, and can be applied to a wide range of packaging materials and packaging containers. To be.

[0011]

According to the present invention, there is provided an oxygen-absorbing resin composition comprising a polyamide resin, an oxidizing organic component, and a transition metal-based catalyst. . In the oxygen-absorbing resin composition of the present invention, The polyamide resin has a terminal amino group concentration of 40 eq / 1.
0 ⁶ g or more, terminal amino group concentration in the more preferred 50eq
It is a polyamide resin of greater than / 10 ⁶ g, 2. 2. the polyamide resin is a polyamide derived from a diamine component mainly composed of xylylenediamine and a dicarboxylic acid component; 3. The oxidizable organic component is a polymer derived from polyenes, particularly an acid-modified polyene-based polymer; 4. the transition metal-based catalyst is a carboxylate of cobalt; The oxidizing organic component is 0.01 to 1 based on the resin composition.
5. It is contained in an amount of 0% by weight; It is preferable that the transition metal-based catalyst be contained in an amount of 100 to 3000 ppm based on the resin composition and in terms of the amount of the transition metal. According to the present invention, there is further provided a packaging material and a packaging container comprising at least one layer made of the oxygen-absorbing resin composition.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Action] The oxygen-absorbing resin composition of the present invention is characterized in that a polyamide resin is used as a base material and an oxidizing organic component and a transition metal catalyst are blended with the base material. Oxygen absorptivity can be exhibited without causing a decrease in oxygen barrier properties due to oxidative deterioration of the compound.

In a known oxygen-absorbing resin composition of a polyamide resin-transition metal catalyst, oxygen is absorbed by oxidizing the polyamide resin. Has a tendency to increase in oxygen permeability. On the other hand, in the oxygen-absorbing resin composition of the present invention, the polyamide resin base material is not substantially oxidized, and the oxidizing organic component is exclusively oxidized, whereby oxygen is absorbed. It is possible to express oxygen absorption without lowering oxygen barrier properties due to oxidative deterioration.

Actually, the constitution (12 μPET, 20 μ barrier material, 50 μCPP, condition (95 ° C., boiled for 30 minutes)), the terminal amino group (AEG) concentration was 27 eq / 10
^A composition comprising ⁶ g of a metaxylylene-based polyamide resin and 400 ppm of a cobalt-based catalyst in terms of cobalt amount,
About a composition in which a metaxylylene-based polyamide resin having a terminal amino group (AEG) concentration of 87 eq / 10 ⁶ g is blended with 5% by weight of an oxidizing organic component (acid-modified diene-based polymer) and 400 ppm of a cobalt-based catalyst in terms of cobalt amount. When the change in the amount of oxygen permeation with time was examined, the amount of oxygen permeation after 30 days was 0.31 cc / cup in the former resin composition, and 0.01 cc / cup in the latter composition.
/ Cup or less, and with the oxygen-absorbing resin composition of the present invention, the permeation of oxygen through the vessel wall can be suppressed extremely low regardless of long-term aging. It is considered that this effect of the present invention is due to the fact that the polyamide resin retains the oxygen barrier property and the oxidizing organic component expresses the oxygen absorbability in a functionally separated manner. FIG.
Shows the relationship between the terminal amino group concentration and the oxygen absorption rate of the meta-xylylene-based polyamide resin, and forms a composition of a meta-xylylene-based polyamide resin having a different terminal amino group concentration with 400 ppm of cobalt neodecanoate in terms of cobalt as a 20 μm-thick film. And this film is 22
The sample was placed in a container of Hyretoflex (described below) conditioned at 60 ° C. and 60% RH, stored for 7 days, and then the oxygen concentration was measured by gas chromatography to determine the oxygen absorption rate. When the terminal amino group concentration of the polyamide resin is 1
In the range of 0 to 30 eq / 10 ⁶ g, the oxygen absorption rate of the polyamide resin is large, and oxidative deterioration is promoted. on the other hand,
When the terminal amino group concentration is in the range of 50 to 70 eq / 10 ⁶ g, the oxygen absorption rate of the polyamide resin is 0, indicating that no oxidative deterioration has occurred.

In the present invention, the polyamide resin having a terminal amino group concentration of 40 eq / 10 ⁶ g or more, more preferably a terminal amino group concentration of more than 50 eq / 10 ⁶ g, is obtained by oxidizing and degrading the polyamide resin. Is preferred in terms of suppressing

According to the study of the present inventors, it has been found that the oxidative deterioration of the polyamide resin, that is, oxygen absorption, and the terminal amino group concentration of the polyamide resin are closely related.
That is, when the terminal amino group concentration of the polyamide resin is in the relatively high range described above, the oxygen absorption rate is suppressed to almost zero or a value close to zero, whereas the terminal amino group concentration of the polyamide resin is reduced. When the ratio falls below the above range, the oxygen absorption rate of the polyamide resin increases. Thus, according to the present invention, by using the combination of the polyamide resin and the oxidizing organic component in the above range, it is possible to selectively perform the oxygen absorption by the oxidizing organic component while suppressing the oxidative deterioration of the polyamide resin. Becomes possible.

The polyamide resin used in the present invention is preferably a polyamide derived from a diamine component mainly composed of xylylenediamine and a dicarboxylic acid component from the viewpoint of oxygen barrier properties. That is, the above xylylene group-containing polyamide resin has an advantage that oxygen permeability is smaller than that of the all aliphatic polyamide resin.

The oxidizing organic component used in the present invention is preferably a polymer derived from polyenes, particularly an acid-modified polyene polymer. Polymers derived from polyenes have a double bond in the main chain or side chain in the polymer. According to Smith's theory, the carbon atom adjacent to the double bond is remarkably activated and easily releases hydrogen gas. In a polymer derived from a polyene, it is considered that a hydrogen atom is easily extracted at a position of a carbon atom adjacent to a carbon-carbon double bond in the polymer, thereby generating a radical. Oxygen absorption in a composition containing a transition metal-based catalyst and the above-mentioned oxidizing organic component is, of course, carried out via oxidation of this organic component. It is believed that this occurs through the elementary reactions of the generation of radicals by abstraction of a hydrogen atom from a double bond adjacent carbon atom, the generation of a peroxy radical by the addition of an oxygen molecule to this radical, and the abstraction of a hydrogen atom by a peroxy radical. .

However, in the presence of a small amount of a transition metal catalyst which does not cause deterioration of the resin even under normal conditions, the generation of the above radicals and the addition of oxygen have an induction period, and these elementary reactions are not always quick and effective. It is thought that it has not been done. On the other hand, the acid-modified polyene polymer suitably used in the present invention has a functional group such as a carboxylic acid group and a carboxylic anhydride group in addition to the carbon atom adjacent to the double bond, It is believed that this has effectively helped to shorten the induction period. That is, all of the functional groups are electron-withdrawing groups, and the reason is that the carbon atom adjacent to the double bond is activated.

In addition, when the acid-modified polyene polymer is blended with the polyamide resin, the dispersibility of the acid-modified polyene-based polymer in the polyamide resin matrix is improved, and the processability of the resin composition is improved. Achieved. That is, in the case of an unmodified polyene polymer,
Since the polyene polymer is simply dispersed by mechanical kneading, the dispersibility is poor, and the degree of dispersion tends to be non-uniform, and the processability of the resin composition also decreases. I can't escape. On the other hand, in the acid-modified polyene-based polymer, due to the presence of the above-described functional group, the affinity for the polyamide resin is large, the dispersibility in the polyamide resin is good, and the processability of the resin composition is excellent. The advantage is that it is achieved.

In the present invention, the transition metal catalyst is preferably a carboxylate of cobalt from the viewpoint of oxygen absorption, and this catalyst has excellent dispersibility in resin and makes the packaging material unsightly. It is also excellent in that it does not color as much as possible.

In the present invention, the oxidizing organic component is preferably contained in an amount of 0.01 to 10% by weight, particularly 0.5 to 8% by weight based on the resin composition. When the amount of the oxidizing organic component is below the above range, the oxygen absorption rate becomes considerably lower than when the amount is within the above range,
Not preferred. On the other hand, when the amount of the oxidizing organic component exceeds the above range, no particular advantage is obtained in terms of the oxygen absorption rate, and the oxygen permeability through the layer of the oxygen-absorbing resin composition increases, resulting in poor moldability. It is not preferable because it becomes worse.

On the other hand, the transition metal catalyst is preferably contained in an amount of 100 to 3000 ppm, particularly 150 to 1000 ppm in terms of the amount of the transition metal, based on the resin composition. When the amount of the transition metal-based catalyst is below the above range, the oxygen absorption rate becomes considerably lower than when the amount is within the above range, and when the amount exceeds the above range, the resin tends to deteriorate significantly. It is not preferable.

[Polyamide Resin] The polyamide resin includes (a) an aliphatic, alicyclic or semi-aromatic polyamide derived from a dicarboxylic acid component and a diamine component, and (b) an aminocarboxylic acid or a lactam thereof. Or a copolyamide thereof or a blend thereof. As the dicarboxylic acid component, for example, aliphatic dicarboxylic acids having 4 to 15 carbon atoms such as succinic acid, adipic acid, sebacic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, and aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid Acids. Further, as the diamine component, a linear or C6-C18, particularly C6-C18, C18 such as 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diaminododecane, etc. Branched alkylenediamine, bis (aminomethyl) cyclohexane, bis (4-aminocyclohexyl) methane, 4,4'-diamino-3,3 '
Alicyclic diamines such as dimethyldicyclohexylmethane, especially bis (4-aminocyclohexyl) methane, 1,3-bis (aminocyclohexyl) methane, 1,3-bis (aminomethyl) cyclohexane, m-xylylenediamine and / or Or araliphatic diamines such as p-xylylenediamine. Examples of the aminocarboxylic acid component include aliphatic aminocarboxylic acids such as ω-aminocaproic acid, ω-aminooctanoic acid, ω-aminoundecanoic acid, ω-aminododecanoic acid, and, for example, para-aminomethylbenzoic acid and para-aminophenylacetic acid. And the like.

For the purpose of the present invention, among these polyamides, xylylene group-containing polyamides are preferred, and specifically, polymethaxylylene adipamide, polymetaxylylene sebacamide, polymetaxylylene veramide, Homopolymers such as paraxylylene pimeramide and polymethaxylylene azeramid, and metaxylylene / paraxylylene adipamide copolymer, metaxylylene / paraxylylene pimeramide copolymer, metaxylylene / paraxylylene sebaca Copolymers such as amide copolymers, meta-xylylene / para-xylylene azeramid copolymers, or components of these homopolymers or copolymers, and aliphatic diamines such as hexamethylene diamine and alicyclic diamines such as piperazine Aromatic diamines such as para-bis (2aminoethyl) benzene, Copolymers obtained by copolymerizing aromatic dicarboxylic acids such as phthalic acid, lactams such as ε-caprolactam, ω-aminocarboxylic acids such as 7-aminoheptanoic acid, and aromatic aminocarboxylic acids such as para-aminomethylbenzoic acid. Among them, a polyamide obtained from a diamine component containing m-xylylenediamine and / or p-xylylenediamine as a main component and an aliphatic dicarboxylic acid and / or an aromatic dicarboxylic acid is particularly preferably used. it can. These xylylene group-containing polyamides are excellent in oxygen barrier properties as compared with other polyamide resins, and are preferable for the purpose of the present invention.

The polyamide resin used in the present invention preferably has a terminal amino group concentration in the above-mentioned range.
If the terminal amino group concentration is lower than the above range, the polyamide resin is deteriorated, which is not preferable.

The polyamide resin having a terminal amino group concentration within the above range can be selected from commercially available polyamide resins. These polyamide resins are used in 98% sulfuric acid because of the mechanical properties of the container and the ease of processing.
A relative viscosity (η rel) measured at a concentration of 1.0 g / dl and a temperature of 20 ° C. is from 1.3 to 4.2, in particular from 1.5 to 3.8
Is desirably within the range.

[Oxidizing Organic Component] The oxidizing organic component used in the present invention is preferably a polymer derived from a polyene. Such polyenes may have 4 to 4 carbon atoms.
Resins containing units derived from 20 polyenes, chain or cyclic conjugated or non-conjugated polyenes are preferably used.
These monomers include, for example, conjugated dienes such as butadiene and isoprene; 1,4-hexadiene, 3-methyl-1,4-
Hexadiene, 4-methyl-1,4-hexadiene, 5-methyl
Chain non-conjugated dienes such as -1,4-hexadiene, 4,5-dimethyl-1,4-hexadiene, 7-methyl-1,6-octadiene; methyltetrahydroindene, 5-ethylidene-2-norbornene, 5- Cyclic non-conjugated dienes such as methylene-2-norbornene, 5-isopropylidene-2-norbornene, 5-vinylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene and dicyclopentadiene;
3-diisopropylidene-5-norbornene, 2-ethylidene
-3-Isopropylidene-5-norbornene, 2-propenyl
Triene such as -2,2-norbornadiene, chloroprene and the like.

These polyenes may be incorporated into homopolymers, random copolymers, block copolymers, etc., alone or in combination of two or more, or in combination with other monomers. Monomers used in combination with the polyene include α-olefins having 2 to 20 carbon atoms,
For example, ethylene, propylene, 1-butene, 4-methyl-1-
Pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-nonadecene, 1-eicosene, 9-
Methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, and styrene, vinyltoluene, acrylonitrile, methacrylonitrile, vinyl acetate, methyl methacrylate, ethyl acrylate The body can also be used.

As the polyene polymer, specifically,
Polybutadiene (BR), polyisoprene (IR), butyl rubber (IIB), natural rubber, nitrile-butadiene rubber (NBR), styrene-butadiene rubber (SB
R), chloroprene rubber (CR), ethylene-propylene-diene rubber (EPDM), and the like, but are not limited to these examples.

The carbon-carbon double bond in the polymer is
It is not particularly limited, and may be present in the main chain in the form of a vinylene group or in the side chain in the form of a vinyl group.

These polyene polymers preferably have a carboxylic acid group, a carboxylic acid anhydride group or a hydroxyl group introduced therein. Examples of the monomer used to introduce these functional groups include the ethylenically unsaturated monomers having the above functional groups.

As these monomers, it is desirable to use unsaturated carboxylic acids or derivatives thereof. Specifically, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid Α, β-unsaturated carboxylic acids such as acids, bicyclo [2,2,
1] unsaturated carboxylic acids such as hept-2-ene-5,6-dicarboxylic acid, α, β unsaturated carboxylic anhydrides such as maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicyclo [2,2,1] Unsaturated carboxylic acid anhydrides such as hept-2-ene-5,6-dicarboxylic anhydride.

The acid modification of the polyene polymer is performed by graft copolymerizing an unsaturated carboxylic acid or a derivative thereof with a resin having a carbon-carbon double bond as a base polymer by a known means. Although it is produced, it can also be produced by randomly copolymerizing the above-mentioned polyene and unsaturated carboxylic acid or its derivative.

The acid-modified polyene-based polymer particularly suitable for the purpose of the present invention comprises an unsaturated carboxylic acid or a derivative thereof in an amount of 0.1 to 1%.
It is preferably contained in an amount of from 01 to 10 mol%. When the content of the unsaturated carboxylic acid or its derivative is in the above range, the acid-modified polyene-based polymer can be well dispersed in the polyamide resin, and oxygen can be absorbed smoothly. Further, a hydroxyl group-modified polyene polymer having a hydroxyl group at a terminal can also be used favorably.

The polyene polymer used in the present invention is 40
The viscosity at 1 ° C. is preferably in the range of 1 to 200 Pa · s from the viewpoint of processability of the oxygen-absorbing resin composition.

[Transition Metal Catalyst] The transition metal catalyst used in the present invention is preferably a Group VIII metal component of the periodic table, such as iron, cobalt, and nickel.
Group metals: Group IV metals such as tin, titanium and zirconium; Group V metals such as vanadium; Group VI metals such as chromium; and Group VII metal components such as manganese. Among these metal components, the cobalt component has a high oxygen absorption rate and is particularly suitable for the purpose of the present invention.

The transition metal catalyst is generally used in the form of a low-valent inorganic or organic acid salt or a complex salt of the above-mentioned transition metal. Examples of the inorganic acid salts include halides such as chlorides, sulfur oxyacid salts such as sulfates, nitrogen oxyacid salts such as nitrates, phosphorus oxyacid salts such as phosphates, and silicates. On the other hand, examples of the organic acid salt include carboxylate, sulfonate, phosphonate and the like, and carboxylate is suitable for the purpose of the present invention. Specific examples thereof include acetic acid, propionic acid, and isopropionate. Acid, butanoic acid, isobutanoic acid, pentanoic acid, isopentanoic acid, hexanoic acid, heptanoic acid, isoheptanoic acid, octanoic acid,
-Ethylhexanoic acid, nonanoic acid, 3,5,5-trimethylhexanoic acid, decanoic acid, neodecanoic acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, lindelic acid, tuzu Transition metal salts such as acids, petroselinic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, formic acid, oxalic acid, sulfamic acid, and naphthenic acid. On the other hand, as the complex of the transition metal, a complex with β-diketone or β-keto acid ester is used, and β-diketone or β-diketone
Examples of keto acid esters include acetylacetone,
Ethyl acetoacetate, 1,3-cyclohexadione, methylenebis-1,3-cyclohexadione, 2-benzyl-1,3-cyclohexadione, acetyltetralone,
Palmitoyltetralone, stearoyltetralone, benzoyltetralone, 2-acetylcyclohexanone,
2-benzoylcyclohexanone, 2-acetyl-1,
3-cyclohexanedione, benzoyl-p-chlorobenzoylmethane, bis (4-methylbenzoyl) methane, bis (2-hydroxybenzoyl) methane, benzoylacetone, tribenzoylmethane, diacetylbenzoylmethane, stearoylbenzoylmethane, palmitoylbenzoylmethane, Lauroylbenzoylmethane, dibenzoylmethane, bis (4-chlorobenzoyl) methane, bis (methylene-3,4-dioxybenzoyl) methane, benzoylacetylphenylmethane, stearoyl (4-methoxybenzoyl) methane, butanoylacetone, Stearoylmethane, acetylacetone, stearoylacetone, bis (cyclohexanoyl) -methane, dipivaloylmethane, and the like can be used.

[Oxygen-absorbing resin composition] In the oxygen-absorbing resin composition of the present invention, the oxidizing organic component is contained in an amount of 0.01 to 10% by weight, especially 0.5 to 10% by weight based on the resin composition.
Preferably, it is contained in an amount of from 8 to 8% by weight. Further, in the resin composition of the present invention, the transition metal-based catalyst has a transition metal amount of 100 to 300 based on the resin composition.
0 ppm, specifically 100 to 800 p for cobalt
pm, 150 to 1500 ppm for iron and 200 to 2000 ppm for manganese.

Various means can be used to mix the oxidizing organic component and the transition metal catalyst with the polyamide resin. There is no particular order in this formulation, and the blending may be performed in any order. For example, by blending an oxidizing organic component with a polyamide resin by dry blending or melt blending, a blend of both can be easily prepared. On the other hand, the transition metal catalyst is smaller in amount than the polyamide resin and the oxidizing organic component, so that the transition metal catalyst is generally dissolved in an organic solvent in order to homogenize the blending.
This solution is mixed with a powdery or granular polyamide resin and an oxidizing organic component, and if necessary, the mixture is dried under an inert atmosphere.

Solvents for dissolving the transition metal catalyst include alcohol solvents such as methanol, ethanol and butanol, ether solvents such as dimethyl ether, diethyl ether, methyl ethyl ether, tetrahydrofuran and dioxane, and ketone solvents such as methyl ethyl ketone and cyclohexanone. Solvents and hydrocarbon solvents such as n-hexane and cyclohexane can be used, and it is generally preferable to use the transition metal catalyst at a concentration such that the concentration becomes 5 to 90% by weight.

The mixing of the polyamide resin, the oxidizing organic component and the transition metal-based catalyst, and the subsequent storage are preferably performed in a non-oxidizing atmosphere so as to prevent oxidation of the composition at a previous stage. For this purpose, mixing or drying under reduced pressure or in a nitrogen stream is preferred. This mixing and drying can be performed at a stage prior to the molding step by using an extruder or an injection machine equipped with a vent type or a dryer. Also, a masterbatch of a polyamide resin and / or an oxidizing organic component containing a transition metal-based catalyst at a relatively high concentration is prepared, and the masterbatch is dry-blended with an unblended polyamide resin,
The oxygen-absorbing resin composition of the present invention can also be prepared. The polyamide used in the present invention has a temperature of 120 to 180 ° C., which is a general drying condition, at a temperature of 0.5 to 2 m.
It is preferable to dry under a reduced pressure of mHg for 2 to 6 hours and use it for molding described later.

Although not generally necessary, the oxygen-absorbing resin composition of the present invention may optionally contain a known activator. Suitable examples of the activator include, but are not limited to, polyethylene glycol, polypropylene glycol, ethylene-vinyl alcohol copolymer, ethylene-methacrylic acid copolymer, and hydroxyl- and / or carboxyl-group-containing polymers such as various ionomers. is there. These hydroxyl and / or carboxyl group-containing polymers can be blended in an amount of 30 parts by weight or less, particularly 0.01 to 10 parts by weight, per 100 parts by weight of the polyamide resin. The oxygen-absorbing resin composition used in the present invention includes a filler, a coloring agent, a heat stabilizer, a weather stabilizer, an antioxidant, an antioxidant, a light stabilizer, an ultraviolet absorber, an antistatic agent, a metal soap, A well-known resin compounding agent such as a lubricant such as wax, a modifying resin or rubber, etc. can be compounded according to a well-known formulation. For example, the incorporation of a lubricant improves biting of the resin into the screw. Lubricants include metal soaps such as magnesium stearate and calcium stearate, hydrocarbons such as fluid, natural or synthetic paraffin, microwax, polyethylene wax and chlorinated polyethylene wax, and fatty acids such as stearic acid and lauric acid. Fatty acid monoamides or bisamides such as stearic acid amide, balmitic acid amide, oleic acid amide, esylic acid amide, methylenebisstearamide, ethylenebisstearamide, butyl stearate, hydrogenated castor oil, ethylene Ester type such as glycol monostearate, alcohol type such as cetyl alcohol and stearyl alcohol, and a mixture thereof are generally used. The amount of the lubricant added is 50 to 10 based on the polyamide.
A range of 00 ppm is appropriate.

[Packaging Material and Packaging Container] The oxygen-absorbing composition of the present invention is a resin film, paper, woven fabric, nonwoven fabric or a laminate thereof having oxygen permeability in the form of powder, granules or sheets. And used for absorbing oxygen in a sealed package. Further, the oxygen-absorbing composition of the present invention can be blended in a resin or rubber for forming a liner or gasket or for forming a coating, and used for absorbing residual oxygen in a package. However, the oxygen-absorbing resin composition of the present invention is particularly preferably used as a packaging material in the form of a film or sheet, and as a packaging container in the form of a cup, tray, bottle, tube container, or the like.

That is, the oxygen-absorbing resin composition of the present invention comprises
Needless to say, the packaging material and the packaging container can be used as a packaging material and a packaging container in the form of a single layer, and at least one layer composed of the oxygen-absorbing resin composition and at least one layer composed of another resin. Can be used as Generally, the oxygen-absorbing resin composition of the present invention is preferably provided inside the outer surface of a container or the like so as not to be exposed on the outer surface of the container or the like, and for the purpose of avoiding direct contact with the contents. It is preferable to provide it outside the inner surface of the container or the like. Thus, it is desirable to use an oxygen-absorbing resin composition as at least one intermediate layer of a multilayer resin packaging material or packaging container.

In the case of a packaging material and a packaging container having a multilayer structure,
Other resin layers combined with the oxygen-absorbing resin composition layer of the present invention include olefin-based resins, thermoplastic polyester resins, and barrier resins. Olefin resins include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE).
PE), linear low density polyethylene (LLDPE), polyethylene (PE) such as linear very low density polyethylene (LVLDPE), polypropylene (PP), ethylene-propylene copolymer, polybutene-1, ethylene-butene-
1 copolymer, propylene-butene-1 copolymer, ethylene-propylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ion-crosslinked olefin copolymer (ionomer) or a blend thereof, etc. Can be
Examples of the thermoplastic polyester resin include polyethylene phthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), a copolymerized polyester thereof, and a blend thereof. Further, the most suitable example of the gas barrier resin is an ethylene-vinyl alcohol copolymer (EVOH), for example, having an ethylene content of 20 to 60 mol%, particularly 25 to 50 mol%. A saponified copolymer obtained by saponifying an ethylene-vinyl acetate copolymer so as to have a saponification degree of 96 mol% or more, particularly 99 mol% or more is used. The saponified ethylene-vinyl alcohol copolymer should have a molecular weight sufficient to form a film, and is generally 0.01 dl / mol as measured at 30 ° C. in a 85:15 phenol: water mixture by weight. g or more, especially 0.05 dl / g
It is desirable to have the above viscosity. Furthermore, as another example of the barrier resin, a cyclic olefin-based copolymer (COC), particularly a copolymer of ethylene and a cyclic olefin, particularly APEL manufactured by Mitsui Chemicals, Inc. can be used.

Suitable examples of the laminated structure for the packaging material and the packaging container are as follows, expressing the oxygen-absorbing resin composition of the present invention as OAR. Further, which layer is on the inner surface side can be freely selected depending on the purpose. Two-layer structure: PET / OAR, PE / OAR, PP / OA
R, three-layer structure: PE / OAR / PET, PET / OAR / P
ET, PE / OAR / PP, EVOH / OAR / PE
T, PE / OAR / COC, 4-layer structure: PE / PET / OAR / PET, PE / OA
R / EVOH / PET, PET / OAR / EVOH / P
ET, PE / OAR / EVOH / COC, Five-layer structure: PET / OAR / PET / OAR / PET,
PE / PET / OAR / EVOH / PET, PET / O
AR / EVOH / COC / PET, PET / OAR / P
ET / COC / PET, PE / OAR / EVOH / CO
C / PET, 6-layer structure: PET / OAR / PET / OAR / EVOH
/ PET, PE / PET / OAR / COC / EVOH /
PET, PET / OAR / EVOH / PET / COC /
PET, 7-layer structure: PET / OAR / COC / PET / EVOH
/ OAR / PET, etc.

In the production of the laminate, an adhesive resin may be interposed between the resin layers as necessary. Examples of such an adhesive resin include a carbonyl (—CO—) group based on carboxylic acid, carboxylic anhydride, carboxylate, carboxylic acid amide, carboxylic acid ester, or the like in a main chain or a side chain of 1 to 700 mm. Equivalent (meq) / 1
A thermoplastic resin is contained at a concentration of 00 g resin, particularly 10 to 500 meq / 100 g resin. Suitable examples of the adhesive resin include ethylene-acrylic acid copolymer, ion-crosslinked olefin copolymer, maleic anhydride-grafted polyethylene, maleic anhydride-grafted polypropylene, acrylic acid-grafted polyolefin, ethylene-vinyl acetate copolymer, copolymer One or a combination of two or more such as a polymerized polyester and a copolymerized polyamide. These resins are
It is useful for lamination by coextrusion or sandwich lamination. In addition, a thermosetting adhesive resin such as an isocyanate-based or epoxy-based resin is used for bonding and laminating the gas barrier resin film and the moisture-resistant resin film formed in advance.

In the packaging material and the packaging container used in the present invention, the thickness of the oxygen-absorbing resin composition is not particularly limited, but is generally in the range of 3 to 100 μm, particularly preferably 5 to 50 μm. That is, when the thickness of the oxygen-absorbing resin composition becomes thinner than a certain range, the oxygen-absorbing performance is inferior,
In addition, there is no particular advantage in terms of oxygen absorption even when the thickness is greater than a certain range, and in terms of economics such as an increase in the amount of resin, and in terms of container characteristics such as reduced material flexibility and flexibility. It is disadvantageous.

In the multilayer packaging material and the packaging container of the present invention, the total thickness is generally 30 to 7000 μm, particularly preferably 50 to 5000 μm, although it varies depending on the application. The thickness of the intermediate layer is 0.5 to 95% of the total thickness, particularly 1 to 50%.
% Is appropriate.

The packaging material and the packaging container of the present invention can be produced by a method known per se except for using the oxygen-absorbing resin composition described above. For example, the film, sheet or tube is formed by melting and kneading the resin composition with an extruder and extruding the resin composition into a predetermined shape through a T-die, a circular die (ring die) or the like. Processed film, blown film, etc. are obtained. The T-die film is biaxially stretched to form a biaxially stretched film. Further, after the resin composition is melt-kneaded with an injection machine, the resin composition is injected into an injection mold to manufacture a container or a preform for manufacturing the container. Further, the resin composition is extruded into a certain molten resin mass through an extruder, and is compressed and molded by a mold, thereby producing a container and a preform for producing the container. The molded article may take the form of a film, a sheet, a parison or pipe for forming a bottle or tube, a preform for forming a bottle or tube, and the like. Forming a bottle from a parison, pipe or preform is facilitated by pinching off the extrudate with a pair of split dies and blowing fluid into the interior. Also, after cooling the pipe or preform, it is heated to the stretching temperature and stretched in the axial direction,
A blow blow bottle or the like is obtained by blow stretching in the circumferential direction by fluid pressure. Further, the film or sheet is subjected to means such as vacuum forming, pressure forming, overhang forming, plug assist forming, etc., thereby obtaining a cup-shaped or tray-shaped packaging container or a lid material formed of a film or sheet. Can be

The packaging material such as a film can be used as various types of packaging bags, and the bag can be produced by a bag production method known per se, such as ordinary pouches having a three- or four-side seal, Gusseted pouches, standing pouches, pillow packaging bags, and the like are included, but are not limited to these examples.

For the production of the multi-layer extruded product, a co-extrusion molding method known per se can be used. For example, the same method as described above except that a multi-layer multi-die is used using a number of extruders according to the type of resin. Extrusion may be performed in the same manner. Further, in the production of a multilayer injection molded article, a multilayer injection molded article can be produced by a co-injection method or a sequential injection method using an injection molding machine of a number corresponding to the type of the resin. Further, extrusion coating or sandwich lamination can be used for the production of a multilayer film or multilayer sheet, and a multilayer film or sheet can also be produced by dry lamination of a film formed in advance.

The packaging material and the packaging container of the present invention are useful as a container capable of preventing a decrease in the flavor of the contents caused by oxygen. The contents that can be filled include beer, wine, fruit juice, carbonated soft drinks, etc. for beverages, fruits, nuts, vegetables, meat products, infant foods, coffee,
Jams, mayonnaise, ketchup, edible oil, dressings, sauces, boiled foods, dairy products, etc.
Examples include cosmetics, gasoline, and other contents that are prone to degradation in the presence of oxygen, but are not limited to these examples.

[0055]

The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples.

(Measurement of Terminal Amino Group Concentration (AEG)) A sample (0.6 mg) was dissolved in 50 ml of a phenol / ethanol mixed solution (volume ratio: 4/1) and then mixed with an ethanol / water mixed solvent (volume ratio: 3/2). 20 ml was added and titration was performed with stirring. As the titrant, a 1 / 200N hydrochloric acid ethanol / water mixture standard solution (volume ratio 1/9) was used, and as the indicator, methyl orange was used. Also, perform the same operation without adding the sample,
Blank measurements were taken. From the titer, the terminal amino group concentration (AEG) was determined using the following equation. When the sample contains a transition metal-based catalyst, only the same amount of the catalyst was dissolved to obtain a titrated AEG ', and the value obtained by subtracting the value was taken as the AEG of the sample. AEG (eq / 10 ⁶ g) = [{(V−V ₀ ) × N × f}}
/ W] × 10 ³ -AEG ′ V: Volume (ml) of 1 / 200N ethanol / water mixture (volume ratio 1/9) required for sample titration V ₀ : 1 / 200N ethanol ethanol required for blank titration A / water mixture specified liquid (volume ratio 1/9) volume (ml) N: normality of ethanol / water mixture specified liquid f: specified liquid factor W: sample emphasis (g) AEG ': correction value (sample is transition metal (When a system catalyst is included)

(Measurement of Oxygen Permeation Amount of Multilayer Film) In a cup-shaped container made of PP / steel foil laminate having an inner volume of 52.0 ml (Hyleflex, manufactured by Toyo Seikan Co., Ltd.)
Then, heat sealing was performed in a nitrogen atmosphere using the multilayer film as a lid. Untreated these cups or 95
After boiled for 30 minutes at 30 ° C, 80% R
H and stored by gas chromatography (GC-8AI
T, GC-3BT: Both manufactured by Shimadzu Corporation, detector:
TCD (100 ° C), column: molecular sieve 5A
(60 ° C.), carrier gas: argon), the oxygen concentration in the cup was measured, and the oxygen transmission amount was calculated from the oxygen concentration.

(Measurement of Oxygen Permeation Amount of Multi-Layer Container) 3 cc of water was put into the multi-layer container, and heat-sealed with a lid containing aluminum under a nitrogen atmosphere. No treatment of these multilayer containers, or 8
Perform boil treatment at 5 ° C for 30 minutes, and 30 ° C and 80% RH
And the oxygen concentration in the multilayer container was measured using the gas chromatography, and the oxygen permeation amount was calculated from the oxygen concentration.

Example 1 The moisture-proof package was opened and the pressure was 1 m.
Polymetaxylylene adipamide resin (manufactured by Toyobo Co., Ltd., T-
600, AEG = 87 eq / 10 ⁶ g), 5% by weight of maleic acid-modified polybutadiene (M-2000-20 manufactured by Nippon Petrochemical Co., Ltd.) as an oxidizing organic component, and cobalt neodecanoate as a transition metal catalyst. Using a T-die extruder (manufactured by Toshiba Machine Co., Ltd.), a T-die temperature of 270 was used for a resin composition containing 400 ppm (DICNATE 5000, manufactured by Dainippon Ink and Chemicals, Inc.) in terms of the amount of cobalt.
At 20 ° C., a film having a thickness of 20 μm was formed. A biaxially stretched polyester film having a thickness of 12 μm was formed on one side of this film, and unstretched polypropylene having a thickness of 50 μm was dry-laminated on the other side using a laminator to form a multilayer film. The multilayer film is heat-sealed at the opening of the Heiletoflex, and 30 ° C./80% RH
After storing for 30 days under the conditions described above, the amount of oxygen permeated into the container was measured.

[Example 2] Hydroxyl-terminated polyisoprene (polyimide manufactured by Idemitsu Petrochemical Co., Ltd.) was used as the oxidizing organic component.
All the components were molded under the same conditions as in Example 1 except that ip) was 5% by weight and the cobalt neodecanoate was 310 ppm in terms of cobalt as a transition metal catalyst, and the amount of oxidized permeation into the container was measured.

Example 3 Molding was carried out under the same conditions as in Example 1 except that the AEG concentration of the polymethaxylylene adipamide resin was changed to 52 eq / 10 ⁶ g, and the amount of oxygen permeated into the container was measured.

Example 4 Except that the above-mentioned cobalt neodecanoate as a transition metal catalyst was changed to 200 ppm in terms of the amount of cobalt, molding was carried out under the same conditions as in Example 1, and the amount of oxygen permeated into the container was measured.

Example 5 Molding was carried out under the same conditions as in Example 1 except that the amount of hydroxyl-terminated polyisoprene was changed to 3% by weight as an oxidizing organic component, and the amount of oxygen permeated into the container was measured.

Example 6 A molding was performed under the same conditions as in Example 1 except that the amount of the maleic acid-modified polybutadiene was changed to 8% by weight as the oxidizing organic component, and the amount of oxygen permeated into the container was measured.

[Comparative Example 1] Molding was performed under the same conditions as in Example 1 except that the AEG concentration of the polymethaxylylene adipamide resin was changed to 27 eq / 10 ⁶ g, and the amount of oxygen permeated into the container was measured.

[Comparative Example 2] Except that cobalt neodecanoate was used as a transition metal-based catalyst in an amount of 80 ppm in terms of cobalt, molding was performed under the same conditions as in Example 1 and the amount of oxygen permeated into the container was measured.

Comparative Example 3 Molding was carried out under the same conditions as in Example 1 except that the amount of maleic acid-modified polybutadiene as the oxidizing organic component was changed to 12% by weight. Table 1 shows the above measurement results.

[0068]

[Table 1]

Example 7 Terminal amino group concentration AEG was 8
5 wt% of maleic acid-modified polybutadiene was added to 7 eq / 10 ⁶ g of polymethaxylylene adipamide resin,
310 ppm of cobalt neodecanoate in terms of cobalt amount
The resin composition is supplied to an extruder for an intermediate layer, a polyethylene terephthalate resin to an extruder for an inner and outer layer, and a maleic acid-modified ethylene-butene-1 copolymer to an extruder for an adhesive. All multilayer sheets were made. The multi-layer sheet was formed by plug-assist air-pressure molding to have a layer structure of 120 μm inner layer / 20 μm adhesive layer / 20 μm intermediate layer / 20 μm adhesive layer / 120 μm outer layer and a height of 1 μm.
A cup-shaped container having a size of 50 mm, a mouth diameter of 60 mm, and a content of 300 ml was prepared. A heat-sealed sealing lid with an aluminum foil laminated on the mouth of the container was used.
After storing for 30 days under the condition of% RH, the amount of oxygen permeated into the container was measured.

Example 8 A polyethylene terephthalate resin having an intrinsic viscosity of 0.83 dl / g was injected into an inner and outer layer injection machine.
Polymetaxylylene adipamide resin dried under the same conditions as in Example 1 (Toyobo Co., Ltd. T-600, AEG =
87 eq / 10 ⁶ g), and maleic anhydride-modified polybutadiene (manufactured by Nippon Petrochemical Co., Ltd.) as an oxidizing organic component.
-2000-20) 5% by weight of cobalt neodecanoate (DICNATE 5000 manufactured by Dainippon Ink and Chemicals, Inc.) as a transition metal catalyst is 400 p in terms of cobalt amount.
The pellets obtained by pelletizing the resin composition added with pm with a twin screw extruder are supplied to an injection machine for an intermediate layer, and are co-injected into an injection mold under the conditions of an injection nozzle temperature of 280 ° C. and a resin pressure of 250 kgf / cm ^2. Molding was performed to form a multilayer preform of two or three layers in which the inner and outer layers were a polyethylene terephthalate resin and the intermediate layer was a polymethaxylylene adipamide resin. The weight of the multilayer preform was 32 g, and the ratio of the intermediate layer was 5% by weight. This multilayer preform is
The multilayer bottle was heated to 0 ° C. and biaxially stretched and blown in a mold heated to 150 ° C. to form a multilayer bottle having a content of 500 cc.
The mouth of the multilayer bottle was sealed, boiled at 85 ° C. for 30 minutes, stored at 30 ° C. and 80% RH for 60 days, and then the oxygen concentration in the container was measured.

Example 9 A multilayer preform was molded under the same conditions as in Example 10, and the multilayer preform was heated at 60 ° C.
Biaxial stretching blow in a mold heated to
A 0 cc multilayer bottle was molded. The mouth of the multilayer bottle was sealed and stored for 60 days at 30 ° C. and 80% RH, and then the oxygen concentration in the container was measured. Table 2 shows the above measurement results.

[0072]

[Table 2]

[0073]

The oxygen-absorbing resin composition of the present invention is characterized in that a polyamide resin is used as a base material, and an oxidizing organic component and a transition metal catalyst are blended with the polyamide resin. Oxygen absorption can be exhibited without causing a decrease in oxygen barrier properties. That is, in the oxygen-absorbing resin composition of the present invention, the polyamide resin base material is not substantially oxidized, and the oxidizing organic component is exclusively oxidized, whereby oxygen is absorbed. It is possible to express oxygen absorption without lowering the oxygen barrier property. In the present invention, the retention of the oxygen barrier property by the polyamide resin and the development of the oxygen absorbency by the oxidizing organic component are performed in a function-separated manner.

In the present invention, the polyamide resin having a terminal amino group concentration of 40 eq / 10 ⁶ g or more, more preferably a terminal amino group concentration of more than 50 eq / 10 ⁶ g, Oxidation degradation can be suppressed.

The oxidizing organic component used in the present invention is preferably a polymer derived from polyenes, especially an acid-modified polyene polymer. In a polymer derived from a polyene, it is considered that a hydrogen atom is easily extracted at a position of a carbon atom adjacent to a carbon-carbon double bond in the polymer, thereby generating a radical. Oxygen absorption in the composition containing the transition metal catalyst and the oxidizing organic component is, of course, performed through oxidation of the organic component, and the oxygen absorption rate and oxygen absorption There is an advantage that the capacity is large.

Under the coexistence of a small amount of a transition metal catalyst that does not cause deterioration of the resin even under normal conditions, generation of the above radicals and
The addition of oxygen has an induction period, and these elementary reactions are not always performed quickly and effectively.However, in the acid-modified polyene polymer preferably used in the present invention, the carbon atom adjacent to the double bond In addition, it has a functional group such as a carboxylic acid group and a carboxylic acid anhydride group, and is useful for shortening the induction period. In addition, when the acid-modified polyene polymer is blended with the polyamide resin, the dispersibility of the acid-modified polyene-based polymer in the polyamide resin matrix is improved, and a very advantageous effect of improving the processability of the resin composition is achieved. .

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the terminal amino group concentration of a meta-xylylene-based polyamide resin and the oxygen absorption rate.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // (C08L 77/00 C08L 21:00) 21:00) B65D 1/00 BF term (Reference) 3E033 BA21 BB01 BB08 CA20 4F100 AB01A AB01H AH08A AH08H AK07 AK28A AK28H AK29 AK41 AK46A AL07A AL07H AT00B BA02 BA03 BA04 BA05 BA10A BA10B CA09A CA30A GB16 JB03 JD03 JD14 JL01 JL08A JL08H YY00A YY00H 4J002 AC012 AC022 AC032 AC062 AC072 AC082 AC092 BB152 BB182 BB212 BC052 BK002 BN052 BN062 BN142 CL001 CL011 CL031 CL051 DD076 DF036 DG046 DH036 DH046 DJ006 ED046 EG046 EV256 EW126 FD202 FD206 GF00 GG00 GG01 GG02

Claims (11)

[Claims] 1. A polyamide resin, an oxidizing organic component,
An oxygen-absorbing resin composition comprising a transition metal-based catalyst. 2. A polyamide resin having a terminal amino group concentration of 4
The oxygen-absorbing resin composition according to claim 1, wherein the composition is a polyamide resin having a weight of 0 eq / 10 ⁶ g or more. 3. The polyamide resin having a terminal amino group concentration of 5
The oxygen-absorbing resin composition according to claim 1 or 2, wherein the polyamide resin is a polyamide resin exceeding 0 eq / 10 ⁶ g. 4. The oxygen-absorbing resin composition according to claim 1, wherein the polyamide resin is a polyamide derived from a diamine component mainly composed of xylylenediamine and a dicarboxylic acid component. object. 5. The oxygen-absorbing resin composition according to claim 1, wherein the oxidizing organic component is a polymer derived from polyenes. 6. The oxygen-absorbing resin composition according to claim 1, wherein the oxidizing organic component is an acid-modified polyene-based polymer. 7. The oxygen-absorbing resin composition according to claim 1, wherein the transition metal catalyst is a carboxylate of cobalt. 8. The composition according to claim 1, wherein the oxidizing organic component is contained in an amount of 0.
The oxygen-absorbing resin composition according to any one of claims 1 to 7, which is contained in an amount of from 01 to 10% by weight. 9. The oxygen-absorbing material according to claim 1, wherein the transition metal-based catalyst is contained in an amount of 100 to 3000 ppm in terms of the amount of the transition metal based on the resin composition. Resin composition. 10. A packaging material comprising at least one layer made of the oxygen-absorbing resin composition according to claim 1. 11. A multilayer container for packaging comprising at least one layer comprising the oxygen-absorbing resin composition according to any one of claims 1 to 9.