JP2001011308A - Oxygen absorbing resin composition and packaging material and packaging container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject oxygen absorbing resin composition excellent in gas barrier property and transparency, having improved oxygen absorbing rate, capable of applying for a use for a packaging material and a container by selecting a polyamide resin having fixed range of terminal amino group concentration and combining it with a transition metal based catalyst. SOLUTION: This resin composition includes (A) a polyamide resin having 10-50 eq/106 g of terminal amino group concentration, and (B) a transition metal based catalyst (carboxylate of cobalt is preferred). A polyamide resin having terminal carboxyl concentration (eq/106 g)/terminal amino group concentration (eq/106 g) ratio of 1-12 is preferred as the component A. For example, a polyamide derived from a diamine component comprising xylylene diamine as the main constituent and dicarboxylic acid component is preferred. The component B of 10-5,000 ppm as the transition metal based on the polyamide resin is preferably included. A packaging material and a packaging container capable of inhibiting reduction of flavor by oxygen are provided from the composition.

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 particularly, to an oxygen-absorbing resin composition having an improved oxygen absorption rate. .

[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.-0% RH is 10 ⁻¹² cc · cm / cm ² · sec · cmHg or less and 20 ° C.
A resin composition in which a transition metal organometallic complex is mixed with a gas-barrier thermoplastic resin having a water adsorption amount of 0.5% or more at -100% RH is used as an intermediate layer, and moisture-resistant plastic is provided on both sides of the intermediate layer. A multi-layer plastic container characterized by a laminated structure provided with a layer of 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 the use of a polyamide, particularly a polyamide containing a xylidene group, 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 packaging containers that are substantially transparent, but has the problem that the oxygen absorption rate is not yet sufficient. have.

In the course of research on an oxygen-absorbing resin composition containing a polyamide resin and a transition metal-based catalyst, the present inventors have found that the terminal amino groups of the polyamide resin have a large effect on the oxygen absorption rate of this resin composition. It has been found that the oxygen absorption rate of the resin composition can be increased by providing a polyamide resin having a terminal amino group suppressed to a certain reference value or less as a polyamide resin. That is, an object of the present invention is to provide an oxygen-absorbing resin composition containing a polyamide resin having an increased oxygen absorption rate and a transition metal-based catalyst. Another object of the present invention is to provide an oxygen-absorbing resin composition which has an increased oxygen absorption rate, is excellent in gas barrier properties and transparency, and can be applied to a wide range of packaging materials and packaging containers. It is in.

[0011]

According to the present invention, there is provided a polymer
Oxygen-absorbing resin containing amide resin and transition metal catalyst
In the composition, the terminal amino group concentration of the polyamide resin is
10 to 50 eq / 10 ⁶oxygen characterized by being g
An absorbent resin composition is provided. Oxygen-absorbing tree of the present invention
In the fat composition, Terminal carboxyl group concentration of polyamide resin (eq /
10⁶g) / terminal amino group concentration (eq / 10⁶g) ratio
Is 1 to 12, Transition metal-based catalyst per polyamide resin, transition metal
It is contained in an amount of 10 to 5000 ppm as an amount.
That, Polyamide resin mainly composed of xylylenediamine
Poly derived from diamine and dicarboxylic acid components
3. an amide; The transition metal catalyst is a cobalt carboxylate.
And are preferred. According to the present invention, further, the oxygen-absorbing property
Characterized by comprising at least one layer made of a resin composition
A packaging material and a packaging container are provided.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Action] In the oxygen-absorbing resin composition of the present invention, a polyamide resin having a terminal amino group concentration of 10 to 50 eq / 10 ⁶ g is selected as the polyamide resin, and the polyamide resin is used as a transition metal catalyst. The feature is that it is combined with the above, whereby the oxygen absorption rate of the resin composition can be significantly improved.

Please refer to FIG. 1 of the accompanying drawings. FIG.
FIG. 2 is a plot of the relationship between the terminal amino group concentration and the oxygen absorption rate for compositions of a xylylene group-containing polyamide having various terminal amino group concentrations and a transition metal catalyst in Examples described later. According to FIG. 1, when the terminal amino group concentration is 67 eq / 10 ⁶ g, the oxygen absorption rate is zero, while the terminal amino group concentration is 10 to 50 eq.
/ 10 ⁶ g, the oxygen absorption rate is 3.0 × 1
The surprising fact that it can be maintained at ^0-4 cc / cm ² · day or more becomes clear.

In the oxygen-absorbing resin composition of the present invention, the terminal carboxyl group concentration (eq / 10
⁶ g) / terminal amino group concentration (eq / 10 ⁶ g) is 1
It is preferably in the range of 12 to 12. FIG. 2 shows the composition of the xylylene group-containing polyamide and the transition metal catalyst having various terminal amino group concentrations and various terminal carboxyl group concentrations in Examples described later, and the terminal carboxyl group concentration /
It is a plot of the relationship between the terminal amino group concentration ratio and the oxygen absorption rate. According to FIG. 2, when the ratio of the terminal carboxyl group concentration / terminal amino group concentration is 0.6, the oxygen absorption rate is zero, while the ratio of the terminal carboxyl group concentration / terminal amino group concentration is zero. When it is 1 to 12, the oxygen absorption rate is 3.0 × 10 ⁻⁴ cc / cm ^2.
-The surprising fact that it can be maintained beyond the day becomes clear.

Generally, a terminal group quantification method is known as one method for measuring the molecular weight of a polymer. For polyamides, a method for determining the relative viscosity (ηrel) under a certain condition is generally adopted as a molecular weight measuring method. However, as shown in the examples described below, even in the case of polyamide having a constant relative viscosity, the terminal amino group concentration may be greatly different, and the oxygen absorption rate in the resin composition is not the molecular weight of the polyamide, but the terminal It is thought that it depends on the amino group concentration.

As described in the above publication, oxygen absorption of a resin composition comprising a transition metal catalyst and a polyamide resin is carried out via oxidation of the polyamide resin by the transition metal catalyst. In this oxidation, radicals are generated by abstraction of hydrogen atoms from a methylene chain (particularly, a methylene chain adjacent to an arylene group) of a polyamide resin by a transition metal catalyst, and a peroxy radical is generated by addition of an oxygen molecule to the radical. Is believed to occur through elementary reactions of abstraction of hydrogen atoms by peroxy radicals.

In the present invention, it is believed that the oxygen absorption rate can be increased by suppressing the terminal amino group concentration of the polyamide resin below a certain reference value for the following reasons. That is, it is considered that the terminal amino group has an action of stably trapping the radical of the adjacent methylene chain, and the trapped radical does not participate in the absorption of oxygen molecules. For this reason, in the case of a polyamide resin composition having a terminal amino group concentration higher than the reference value, an induction period appears in oxygen absorption, resulting in a decrease in oxygen absorption rate.
On the other hand, in the resin composition of the present invention, it is believed that the induction period is eliminated or shortened, resulting in an increase in the oxygen absorption rate.

[Oxygen-absorbing resin composition]
The yielding resin composition has a terminal amino group concentration of 10 to 50 eq.
/ 10 ⁶g, preferably 10 to 40 eq / 10⁶g,
Most preferably, 10 to 30 eq / 10⁶g polyamid
And a transition metal-based catalyst.

Examples of the polyamide resin include (a) an aliphatic, alicyclic or semi-aromatic polyamide derived from a dicarboxylic acid component and a diamine component, (b) a polyamide derived from an aminocarboxylic acid or a lactam thereof, or These copolyamides or blends thereof are exemplified. 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'-dimethyldicyclohexylmethane, especially bis (4-aminocyclohexyl) methane, 1,3-bis (aminocyclohexyl) methane, 1,3-
Alicyclic diamines such as bis (aminomethyl) cyclohexane; and araliphatic diamines such as m-xylylenediamine and / or p-xylylenediamine. As the aminocarboxylic acid component, aliphatic aminocarboxylic acids such as ω-aminocaproic acid, ω-aminooctanoic acid, ω-
Examples thereof include aminoundecanoic acid and ω-aminododecanoic acid, and araliphatic aminocarboxylic acids such as para-aminomethylbenzoic acid and para-aminophenylacetic acid.

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 preferable from the viewpoint of oxygen absorption because radical generation and oxygen absorption (peroxide generation) occur efficiently in the methylene chain adjacent to the benzene ring.

The polyamide resin used in the present invention has a terminal amino group concentration in the above-mentioned range. If the terminal amino group concentration exceeds the above range, the oxygen absorption rate decreases, which is not preferable. On the other hand, if the terminal amino group concentration is too low, there is a limit to the improvement of the oxygen absorption rate.

The polyamide resin used in the present invention comprises:
When the ratio of terminal carboxyl group concentration / terminal amino group concentration is 1
-12, preferably 2-11.
If the ratio of terminal carboxyl group concentration / terminal amino group concentration exceeds the above range, the oxygen absorption rate decreases, which is not preferable. On the other hand, if the ratio is too low, the improvement of the oxygen absorption rate is limited.

The polyamide resin having a terminal amino group concentration or a terminal carboxyl group concentration / terminal amino group concentration within the above range can be selected from commercially available polyamide resins. Generally, the polyamide resin produced by the solid-state polymerization method has a terminal amino group concentration within a lower range than the polyamide resin produced by another polymerization method.
Further, even in a polyamide resin having a terminal amino group concentration exceeding the range specified in the present invention, a polyamide resin having a terminal amino group concentration satisfying the conditions of the present invention can be obtained by taking measures to reduce the terminal amino group concentration. it can. For example, during or after the production process of the polyamide, the terminal amino group is subjected to acylation to block the terminal amino group, whereby the terminal amino group can be reduced. As the acylating agent used for this purpose, acids such as acetic anhydride, acetyl chloride, benzoyl chloride, and toluenesulfonic acid;
Examples thereof include an acid anhydride and an acid halide, but are not limited to these examples.

These polyamide resins have a relative viscosity (η rel) of from 1.3 to 1.0 g / dl in 98% sulfuric acid and a temperature of 20 ° C., because of the mechanical properties of the container and the ease of processing. It is desirable to be in the range of 4.2, especially 1.5 to 3.8.

The transition metal catalyst used in the present invention includes:
Preference is given to Group VIII metal components of the periodic table such as iron, cobalt and nickel, but also to Group I metals such as copper and silver: Group IV metals such as tin, titanium and zirconium, and V of vanadium.
Group, chromium group VI such as chromium, and VII group metal component 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 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, and phosphonate, and carboxylate is suitable for the purpose of the present invention. Specific examples thereof include acetic acid, propionic acid, and isopropionate. Acids, 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 or β-diketone is used.
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.

In the resin composition of the present invention, the transition metal-based catalyst has a transition metal content of 10 per polyamide resin.
From 5000 to 5000 ppm, especially 50 to 3000 ppm
Is preferably contained in an amount of When the amount of the transition metal-based catalyst is below the above range, the oxygen absorption rate is undesirably reduced as compared with the case where the amount is within the above range. On the other hand, even when this amount exceeds the above range, the oxygen absorption rate is further improved. However, it is not preferable because there is a problem of deterioration and coloring of the resin during molding.

Various means can be used for blending the transition metal catalyst with the polyamide resin. For example, the transition metal catalyst can be simply blended with the polyamide resin by a dry method.However, since the transition metal-based catalyst is smaller in amount than the polyamide, the transition metal catalyst is generally mixed with an organic solvent in order to homogenize the blending. It is preferable to dissolve, mix this solution with a powdery or granular polyamide resin, and dry this mixture under an inert atmosphere if necessary.

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 with the transition metal-based catalyst and the subsequent storage are preferably carried out in a non-oxidizing atmosphere so as to prevent oxidation of the composition in the preceding stage. For this purpose, mixing or drying under reduced pressure or in a nitrogen stream is preferred. This mixing and drying can be carried out at an earlier stage of the molding process by using an extruder or an injection machine equipped with a vent type or a dryer. In this case, the storage of the transition metal catalyst-containing polyamide resin is special. The advantage that no consideration is required is achieved. Also, a masterbatch of a polyamide resin containing a transition metal-based catalyst at a relatively high concentration is prepared, and the masterbatch is dry-blended with an unblended polyamide resin to prepare the oxygen-absorbing resin composition of the present invention. You can also. The polyamide used in the present invention has a temperature of 120 to 180 ° C., which is a general drying condition, and has a viscosity of 0.5%.
It is preferable to dry it for 2 to 6 hours under a reduced pressure of 1 to 2 mmHg and use it for molding described later.

Although not generally required, 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, or the like 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 per 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), linear very low density polyethylene (LVLDPE), isotactic polypropylene (PP), ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 copolymer, Examples thereof include a propylene-butene-1 copolymer, an ethylene-propylene-butene-1 copolymer, an ethylene-vinyl acetate copolymer, an ion-crosslinked olefin copolymer (ionomer), and a blend thereof. Also,
As the thermoplastic polyester resin, polyethylene phthalate (PET), polybutylene terephthalate (PB)
T), 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%. An ethylene-vinyl acetate copolymer having a saponification degree of 96
A saponified copolymer obtained by saponification so as to have a molar percentage of at least 99 mol% is used. The saponified ethylene vinyl alcohol copolymer should have a molecular weight sufficient to form a film, and is generally used in a mixed solvent of phenol: water at a weight ratio of 85:15 at 30 ° C.
It is desirable that the resin has a viscosity of 0.01 dl / g or more, particularly 0.05 dl / g or more, as measured by the method described above. Still another example of the barrier resin is a cyclic olefin-based copolymer (CO
C), 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 packaging materials and packaging containers are as follows, where the oxygen-absorbing resin composition of the present invention is represented 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, OPP / O
AR, three-layer structure: PE / OAR / PET, PET / OAR / P
ET, PE / OAR / OPP, 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. Such adhesive resins include carboxylic acid, carboxylic anhydride, carboxylic acid In the main chain or side chain, from 1 to 700 milliequivalent (meq) / 100 g resin, especially from 10 to 500 meq / 10
A thermoplastic resin contained at a concentration of 0 g resin is exemplified.
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 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 1 μm or more, particularly 3 μm in terms of oxygen absorption.
It is preferable to have the above thickness. On the other hand, the thickness of the oxygen-absorbing resin composition is generally 100 μm or less, particularly 50 μm.
Advantageously, it has the following thickness: That is, even if the thickness of the oxygen-absorbing resin composition becomes thicker than a certain range, there is no particular advantage in terms of oxygen absorbing properties, and economical points such as an increase in the amount of resin, and flexibility and flexibility of the material. This is because there is a disadvantage in terms of container characteristics such as a decrease in

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. On the other hand, the thickness of the oxygen-absorbing resin composition 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 that the above-described oxygen-absorbing resin composition is used. 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, by applying the film or sheet to a means such as vacuum forming, pressure forming, stretch forming, plug assist forming, etc., a cup-shaped or tray-shaped packaging container can be obtained.

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 three- or four-side sealed pouches, 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.

[0043]

The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. A sample was prepared in the following manner and used for the following experiment.

Oxygen-absorbing Film A poly (m-xylylene adipamide) resin pellet was used to produce an oxygen-absorbing film having a thickness of 30 μm using Labo Plastomill Co., Ltd. (manufactured by Toyo Seiki Seisaku-sho, Ltd.). The temperature settings of the molding machine were all set to 270 ° C.

Oxygen-absorbing biaxially stretched film PET resin (J125T manufactured by Mitsui Chemicals, Inc.) and poly (m-xylylene adipamide) resin pellets (MX-nylon 6007: manufactured by Mitsubishi Gas Chemical Co., Ltd.) ) Was coated with 400 ppm (cobalt amount) of cobalt acetate, and a two-type, five-layer multilayer preform was molded by a co-injection molding machine (manufactured by Husky). The preform was reheated to 95 ° C. to perform biaxial stretch blow molding. The oxygen-absorbing material layer of the obtained multilayer bottle was peeled off to obtain an oxygen-absorbing biaxially stretched film. The basis weight of the bottle is 33.7
g, and the stretching ratio is 2.3 × 4.0 for the inner layer and 2.3 for the outer layer.
× 2.7. The layer configuration is as follows. Layer configuration | PET | Oxygen-absorbing material | PET | Oxygen-absorbing material | PET | (%) 30 2.5 35 2.5 30

Measurement of Terminal Amino Group Concentration (AEG) A 0.6 mg sample was mixed with a phenol / ethanol mixed solution (4
/ 1 v / v) after dissolving in 50 ml, ethanol
20 ml of a water mixed solvent (3/2 v / v) was added and titration was performed with stirring. As a titrant, a 1/200 N ethanol / water mixture (1/9 v / v) was used, and as an indicator, methyl olein was used. In addition, the same operation was performed without adding a sample to obtain a blank measurement. From the titer, the terminal amino group concentration (AEG) was determined using the following equation. When the sample contained a transition metal catalyst, only the same amount of the catalyst was dissolved to obtain a titrated AEG ′, and the value obtained by subtracting this was used as the AEG of the sample. WV: 1 / 200N HCl / ethanol required for sample titration
Water mixed normal solution (1 / 9v / v) amount (ml) _{V 0:} blank titration took was 1/200 N hydrochloric acid ethanol-water mixed normal solution (1 / 9v / v) amount (ml) N: Ethanol water mixture Normality of specified solution f: Factor of specified solution W: Weight of sample (g) AEG ': Correction value (when sample contains transition metal catalyst)

Measurement of Terminal Carboxyl Group Concentration (CEG) A sample (0.6 mg) was dissolved in benzyl alcohol (50 ml) and titrated with stirring. 1/100 N for titrant
Potassium hydroxide ethanol / water mixture specified solution (9/1
v / v), phenolphthalein was used as the indicator.
In addition, the same operation was performed without adding a sample to obtain a blank measurement. From the titration amount, the terminal carboxyl group concentration (CEG) was determined using the following equation. V: 1/100 N potassium hydroxide tanol / water mixture (9/1 v / v) volume (ml) required for sample titration V ₀ : 1/100 N potassium hydroxide ethanol / water mixture required for blank titration Normal liquid (9/1 v / v) volume (ml) N: Normality of normal liquid mixture of ethanol and water f: Factor of normal liquid W: Sample weight (g)

Oxygen Absorbing Performance An oxygen-absorbing packaging material film was cut into 96 cm ² ,
A 52.0 ml inner volume of a Hireto cup (HR78-84W) together with 2.0 ml of a humidity control liquid (70% glycerin aqueous solution)
(Made by Toyo Seikan Co., Ltd.) and sealed by heat sealing with a lid material containing aluminum, and stored at 22 ° C.-60% RH. After storage for 7 days, gas chromatography (GC-8A)
IT, GC-3BT: both manufactured by Shimadzu Corporation, detector: TCD (60 ° C), column: molecular sieve 5
A (100 ° C.), carrier gas: argon, was used to measure the oxygen concentration. The oxygen absorption amount was calculated from the oxygen concentration, and the absorption amount per day was defined as the oxygen absorption rate.

Example 1 Poly (m-xylylene adipamide) resin pellets (MX-nylon 6007: manufactured by Mitsubishi Gas Chemical Co., Ltd.) were opened immediately after opening the moisture-proof packaging and at a pressure of 1 mm.
After drying for 4 hours under the condition of Hg or lower and a temperature of 150 ° C., 400 ppm (cobalt amount) of cobalt acetate was adhered to form a film. The oxygen absorption rate and AEG and CEG of the obtained film were measured. Dry AEG CEG CEG / AEG Oxygen absorption rate treatment (eq / 10 ⁶ g) (eq / 10 ⁶ g) (cc / cm ² / day × 10 ⁻⁴ ) No 26 62 2.3 3.29 Yes 16 83 5. 2 4.43

Example 2 Biaxial stretch blow molding was performed.
The oxygen-absorbing material layers (inner and outer layers) of the obtained multilayer bottle were peeled off to obtain an oxygen-absorbing biaxially stretched film.
The oxygen absorption rate and AEG and CEG of the obtained film were measured. Oxygen absorption AEG CEG CEG / AEG Oxygen absorption rate material layer (eq / 10 ⁶ g) (eq / 10 ⁶ g) (cc / cm ² / day × 10 ⁻⁴ ) Inner layer 10 108 10.6 5.49 Outer layer 12 119 9.9 3.55

Example 3 Poly (m-xylylene adipamide) resin pellets (MX-Nylon 6007: manufactured by Mitsubishi Gas Chemical Co., Ltd.) were used at a pressure of 1 mmHg or less and a temperature of 150.
After drying at 4 ° C. for 4 hours, cobalt carboxylate (cobalt acetate, cobalt stearate, cobalt neodecanoate, cobalt citrate) was added for 40 hours each.
0 ppm (amount of cobalt) was attached to form a film. The oxygen absorption amount of the obtained film was measured. As a result, the films using cobalt acetate, cobalt stearate, and cobalt neodecanoate exhibited almost the same excellent oxygen absorbing ability. Added cobalt carboxylate Oxygen absorption rate (cc / cm ² / day × 10 ⁻⁴ ) Cobalt acetate 4.43 Cobalt stearate 6.89 Cobalt neodecanoate 4.67 Cobalt citrate 0

[Comparative Example 1] Poly (m-xylylene adipamide) resin pellets (T-630: manufactured by Toyobo Co., Ltd.) were prepared immediately after opening the moisture-proof package, at a pressure of 1 mmHg or less and at a temperature of 150 ° C. After drying for an hour, 400 ppm (amount of cobalt) of cobalt acetate was adhered to form a film. Oxygen absorption rate of the obtained film and A
EG and CEG were measured. Dry AEG CEG CEG / AEG Oxygen absorption rate treatment (eq / 10 ⁶ g) (eq / 10 ⁶ g) (cc / cm ² / day × 10 ⁻⁴ ) None 67 40 0.60 Yes 58 37 0.60

Comparative Example 2 400 ppm of cobalt acetate was added to poly (m-xylylene adipamide) resin pellets.
(Cobalt amount) was adhered to prepare a film having the following AEG and CEG. The oxygen absorption amount of the obtained film was measured. AEG CEG CEG / AEG Oxygen absorption rate (eq / 10 ⁶ g) (eq / 10 ⁶ g) (cc / cm ² / day × 10 ⁻⁴ ) 8 102 12.9 0.06 7 92 13.9 0.66

Comparative Example 3 Cobalt acetate was adhered to poly (m-xylylene adipamide) resin pellets (MX-nylon 6007: manufactured by Mitsubishi Gas Chemical Company, Ltd.) to form a film. 5000 ppm of cobalt acetate added
(Cobalt amount), oxygen absorption performance equivalent to that of the additive amount of 400 ppm was obtained. At an addition amount of 7000 ppm, the melt viscosity after extrusion decreased, and it was impossible to form a film. When no cobalt acetate was added and the content was 0 to 5 ppm, the oxygen absorption was 0 cc.

Comparative Example 4 Poly (m-xylylene adipamide) resin pellets (MX-nylon 6007: manufactured by Mitsubishi Gas Chemical Co., Ltd.) were added to a transition metal acetate salt (manganese acetate,
Iron acetate) was attached at 400 ppm (transition metal amount) to form a film. When the oxygen absorption of the obtained film was measured, the oxygen absorption of the film using manganese acetate and iron acetate was both 0 cc.

[0056]

According to the present invention, it has been found that the terminal amino group of the polyamide resin has a great effect on the oxygen absorption rate of the resin. As the polyamide resin to be used, a polyamide resin in which the terminal amino group is suppressed to a certain reference value or less is used. And combining this with a transition metal-based catalyst,
The oxygen absorption rate of the resin composition can be increased. INDUSTRIAL APPLICABILITY The resin composition of the present invention has an increased oxygen absorption rate and is also excellent in transparency, and is useful for application to a wide range of packaging materials and packaging containers to prevent a decrease in flavor due to oxygen. is there.

[Brief description of the drawings]

FIG. 1 is a graph plotting the relationship between the terminal amino group concentration and the oxygen absorption rate for compositions of a xylylene group-containing polyamide having various terminal amino group concentrations and transition metal catalysts in Examples.

FIG. 2 shows the ratio of terminal carboxyl group concentration / terminal amino group concentration and oxygen absorption for compositions of a xylylene group-containing polyamide and a transition metal catalyst having various terminal amino group concentrations and various terminal carboxyl group concentrations in Examples. It is the graph which plotted the relationship with speed.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E067 AA03 AB04 AB08 AB09 AB23 AB26 AB28 AB81 AB96 BA03A BA04A BB08A BB11A BB14A BB22A CA04 CA11 CA30 GD02 4J002 CL031 DD076 DG046 DH046 DJ006 EE046 EG046 FD206 GG01

Claims (7)

[Claims] 1. A method comprising a polyamide resin and a transition metal catalyst.
An oxygen-absorbing resin composition having a polyamide resin
Has a terminal amino group concentration of 10 to 50 eq / 10 ⁶g
An oxygen-absorbing resin composition, comprising: 2. The terminal carboxyl group concentration (eq / 10 ⁶ g) / terminal amino group concentration (eq / 10) of the polyamide resin.
The ratio of ⁶ g) is from 1 to 12.
The oxygen-absorbing resin composition according to the above. 3. The oxygen-absorbing resin composition according to claim 1, wherein the transition metal-based catalyst is contained in an amount of 10 to 5000 ppm as a transition metal per polyamide resin. 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 transition metal catalyst is a carboxylate of cobalt. 6. A packaging material comprising at least one layer made of the oxygen-absorbing resin composition according to claim 1. 7. A packaging container comprising at least one layer made of the oxygen-absorbing resin composition according to any one of claims 1 to 5.