JP2003012944A - Resin composition having excellent moldability and gas barrier property, and packaging material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition which has excellent oxygen absorbency, and decreases oxygen permeation through a resin layer over a long time, and besides, has excellent moldability and mechanical strength. SOLUTION: The resin composition having the excellent moldability and gas barrier property comprises a thermoplastic resin which has solubility parameter (an Sp value) of >=9.5 and is possible to melt extrude, an organic component having a functional group at a side chain or a terminal, and a transition-metal catalyst.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resin composition having excellent moldability and gas barrier properties, and a packaging material formed from the resin composition.

[0002]

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

In particular, in metal cans and glass bottles, the oxygen permeation through the container wall is zero, and only oxygen remaining in the container is a problem, whereas in the case of a plastic container, the oxygen permeation through the container wall does not occur. It occurs in an order that cannot be ignored, and is a problem in terms of the storability of the contents.

In order to prevent this, in the plastic container, the container wall has a multi-layer structure, and at least one of them has a resin having oxygen permeation resistance such as ethylene-vinyl alcohol copolymer. There is.

An oxygen scavenger has been used for a long time to remove oxygen in a container, and an example of applying the oxygen scavenger to a packaging material is the invention of Japanese Patent Publication No. 62-1824. According to the above, a multilayer structure for packaging is obtained by laminating a layer formed by mixing a resin having oxygen permeability with a deoxidizer containing a reducing substance such as iron powder as a main component and a layer having an oxygen gas barrier property. And

Japanese Patent Publication No. 4-608 relating to the proposals of the present inventors
No. 26 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 ° C.
And a resin composition obtained by blending a gas barrier thermoplastic resin having a water adsorption amount at 100% RH of 0.5% or more with an organometallic complex of a transition metal as an intermediate layer, and a moisture-resistant heat-resistant material on both sides of the intermediate layer. A plastic multi-layer container characterized in that it consists of a laminated structure provided with layers of a plastic resin is described.

In Japanese Patent No. 2991437, in a packaging barrier containing a composition comprising a polymer and having oxygen scavenging properties or a layer of the composition, the composition captures oxygen by metal-catalyzed oxidation of an oxidizable organic component. A packaging barrier is described which is characterized in that it is assembled, and it is also described that polyamides, in particular xylylene group-containing polyamides, are used as oxidizable organic components.

[0008]

The method of blending an oxygen absorbent such as iron powder with the resin and using it for the container wall of the packaging material is satisfactory in that it has a high oxygen absorption performance, but the resin is not used. There is an application restriction that it cannot be used in the field of packaging where transparency is required because it is colored in a specific hue.

On the other hand, the oxygen-absorbing resin composition containing a transition metal-based catalyst has an advantage that it can be applied to a packaging container which is substantially transparent. However, there is a drawback in that the permeation of oxygen through the vessel wall increases over time and the strength of the container decreases as well because it deteriorates due to oxidation.

The present inventors have found that a resin composition in which an oxidizing organic component and a transition metal catalyst are mixed in a specific thermoplastic resin is excellent in moldability and gas barrier property. I found it. That is, an object of the present invention is to provide a resin composition which has excellent oxygen absorbability, can reduce oxygen permeation through the resin layer for a long time, and is also excellent in moldability and mechanical strength. There is. Another object of the present invention is a packaging provided with a resin layer of a function separation type in which the resin composition layer has excellent oxygen absorption and the resin layer itself also has excellent oxygen barrier properties and strength. In providing the material.

[0011]

According to the present invention, (A)
A melt-extrudable thermoplastic resin having a solubility index (Sp value) of 9.5 or more, (B) an organic component having a functional group at a side chain or a terminal and capable of being oxidized, and (C) a transition metal catalyst. A resin composition having excellent moldability and gas barrier properties is provided. In the resin composition of the present invention, 1. 1. The thermoplastic resin is present as a continuous phase and the oxidizable organic component is present as a dispersed phase. 2. The thermoplastic resin comprises at least one resin selected from the group consisting of ethylene-vinyl alcohol copolymer, polyamide or its copolymer and polyester. 3. The oxidizable organic component comprises a polyene oligomer or polymer modified with an acid or an acid anhydride; 4. The oxidizable organic component is dispersed in the thermoplastic resin with a dispersed particle diameter having a minimum length of 400 nm or less. 5. the transition metal catalyst is an organic salt of at least one metal selected from the group consisting of cobalt, manganese, copper and iron; The resin composition contains 0.01 to 10 oxidizing organic components.
It is preferable that the transition metal catalyst is present in an amount of wt%, and based on the total amount thereof, the transition metal catalyst is present in an amount of at least 300 ppm in terms of metal amount. According to the present invention, there is also provided a plastic container having excellent moldability and gas barrier properties, which is characterized by having at least one layer made of the above resin composition. In the packaging material of the present invention, it is preferable that the layer is an intermediate layer and further has an inner layer and an outer layer made of a moisture resistant resin.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION [Function] The resin composition of the present invention comprises a thermoplastic resin, an oxidizing organic component and a transition metal catalyst. The thermoplastic resin has a solubility index (Sp value) of 9. A thermoplastic resin which is 5 or more and melt-extrudable is selected, and as the oxidizable organic component (also referred to as an oxidizable organic component), an oxidizable organic component having a functional group at a side chain or a terminal is selected, The feature is that these are combined.

It is important for the thermoplastic resin used in the present invention to have a solubility index of 9.5 or more in terms of physical properties such as gas barrier property and strength of the resin composition. In the present specification, the solubility index (Solubility Parameter Sp value) is defined as the 1/2 power value of the cohesive energy density (cal / cc), and is closely related to the strength of hydrogen bond. Indicates that the larger the value of, the greater the degree of hydrogen bond strength.

The thermoplastic resin used in the present invention is a main component of the resin composition, that is, a matrix. The thermoplastic resin has a solubility index (Sp) within the above range.
By having a value), the degree of hydrogen bonding is large, and thereby excellent gas barrier properties can be obtained. In addition, a thermoplastic resin having a solubility index (Sp value) in the above range has an advantage that the cohesive energy density is high, the mechanical strength of the resin composition can be maintained high, and satisfactory moldability can be obtained. It is a thing.

In the present invention, as the oxidizable organic component, an oxidizable organic component having a functional group at its side chain or terminal is used. The oxidizing organic component has a function of absorbing oxygen by being exclusively oxidized by the action of a transition metal catalyst described later, and the oxidizing organic component has a functional group at a side chain or a terminal. By using, it is possible to improve the dispersibility of the oxidizing organic component in the thermoplastic resin, obtain excellent processability, and accelerate the absorption of oxygen due to the oxidation of the oxidizing organic component.

It is considered that in the oxidizing organic component, the hydrogen atom is easily abstracted at the position of the active carbon atom of the organic component, and thereby the radical is generated. The oxygen absorption in the composition containing the transition metal catalyst and the oxidizing organic component is, of course, carried out via the oxidation of the organic component, and the oxidation is performed by the transition metal catalyst. It is believed to occur through the elementary reactions of generation of radicals by abstraction of hydrogen atoms from atoms, generation of peroxy radicals by addition of oxygen molecules to the radicals, and abstraction of hydrogen atoms by peroxy radicals.

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, there is an induction period for the above radical generation and oxygen addition, and these elementary reactions are not always rapid and effective. It seems that it has not been done. On the other hand, the functional group-containing oxidizing organic component used in the present invention has a functional group such as a carboxylic acid group and a carboxylic acid anhydride group, which is effective in shortening the induction period. Can be believed. That is, it may be because all the functional groups are electron-withdrawing groups and activate the carbon atoms adjacent to the double bond.

In addition, when a functional group-containing oxidizing organic component is added to the thermoplastic resin, the dispersibility of the oxidizing organic component in the thermoplastic resin matrix is improved, and the processability of the resin composition is improved, which is extremely convenient. The action of is achieved. That is, in the case of an unmodified oxidizing organic component, since it is dispersed simply by mechanical kneading, the dispersibility tends to be poor, and the degree of dispersion tends to be uneven, and the resin composition Inevitably, the workability also deteriorates.
On the other hand, the functional group-containing oxidizing organic component has a large affinity for a thermoplastic resin having a large Sp value due to the presence of the above-described functional group, and has a good dispersibility in a thermoplastic resin such as a polyamide resin. The advantage that the processability of the resin composition is excellent is achieved.

In the resin composition of the present invention, as described above, the thermoplastic resin does not substantially oxidize and serves for gas barrier properties, while the oxidizable organic component helps to absorb oxygen by oxidation, thus blocking gas. It is a distinctive feature that the function and the oxygen absorption are performed by separate function division.

In particular, in a dispersed structure in which the thermoplastic resin is present as a continuous phase (matrix) and the oxidizable organic component is present as the dispersed phase, the surface area of the oxidizable organic component as the dispersed phase is increased, Oxygen is efficiently absorbed, and since the thermoplastic resin remains as a continuous phase even after the oxidation of the dispersion layer proceeds, there is an advantage that excellent gas barrier property and mechanical strength are maintained. Also, since the oxidizing organic component is covered with the continuous phase of the thermoplastic resin,
It also has the advantage of excellent hygienic properties.

[Thermoplastic Resin] The thermoplastic resin used in the resin composition of the present invention has a solubility index (Sp value) of 9.5 or more and is melt extrudable. Any thermoplastic resin can be used as long as the above conditions are satisfied,
Particularly preferable examples include ethylene-vinyl alcohol copolymers, polyamides and copolymers thereof, barrier polyesters, and combinations thereof.

As a resin having a particularly excellent barrier property against oxygen and aroma components, an ethylene-vinyl alcohol copolymer can be mentioned. For example, the ethylene content is 20.
To 60 mol%, particularly 25 to 50 mol%, of an ethylene-vinyl acetate copolymer saponified to 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 measured at 30 ° C. in a mixed solvent of 85:15 by weight of phenol: water. It is desirable to have a viscosity of / g or more, particularly 0.05 dL / g or more.

As the polyamide resin, (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 their blends are mentioned.

Examples of the dicarboxylic acid component include succinic acid, adipic acid, sebacic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, and other aliphatic dicarboxylic acids having 4 to 15 carbon atoms, terephthalic acid, and isophthalic acid. Aromatic dicarboxylic acids are mentioned.
Further, as the diamine component, 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecane, 1,1
Carbon number of 2-diaminododecane etc. 4 to 25, especially 6 to 18
Linear or branched alkylenediamine, bis (aminomethyl) cyclohexane, bis (4-aminocyclohexyl) methane, 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, especially bis (4-amino) Cycloaliphatic diamines such as cyclohexyl) methane, 1,3-bis (aminocyclohexyl) methane, and 1,3-bis (aminomethyl) cyclohexane, araliphatic such as m-xylylenediamine and / or p-xylylenediamine Examples include diamines.

As the aminocarboxylic acid component, an aliphatic aminocarboxylic acid such as ω-aminocaproic acid, ω-aminooctanoic acid, ω-aminoundecanoic acid, ω-aminododecanoic acid or, for example, para-aminomethylbenzoic acid, para- Examples thereof include araliphatic aminocarboxylic acids such as aminophenylacetic acid.

Of these polyamides, xylylene group-containing polyamides are preferable, and specifically, polymetaxylylene adipamide, polymetaxylylene sebacamide, polymetaxylylene sveramide, polyparaxylylene pimeramide, Homopolymers such as polymethaxylylene azelamide, and metaxylylene / paraxylylene adipamide copolymers, metaxylylene / paraxylylene pimeramide copolymers, metaxylylene / paraxylylene sebacamide copolymers, metaxylylene / Copolymers such as paraxylylene azeramide copolymers, or components of homopolymers or copolymers thereof with aliphatic diamines such as hexamethylenediamine, alicyclic diamines such as piperazine, and para-bis (2amino). Aromatic diamines such as ethyl) benzene,
Aromatic dicarboxylic acids such as terephthalic acid, lactams such as ε-caprolactam, ω such as 7-aminoheptanoic acid
-Aminocarboxylic acid, a copolymer obtained by copolymerizing an aromatic aminocarboxylic acid such as para-aminomethylbenzoic acid, and the like, but a diamine mainly containing m-xylylenediamine and / or p-xylylenediamine A polyamide obtained from the component and an aliphatic dicarboxylic acid and / or an aromatic dicarboxylic acid can be particularly preferably used. 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.

In the present invention, the polyamide resin has a terminal amino group concentration of 40 eq / 10 ⁶ g or more, and more preferably a terminal amino group concentration of more than 50 eq / 10 ⁶ g. It is preferable in that There is a close relationship between oxidative deterioration of the polyamide resin, that is, oxygen absorption, and the terminal amino group concentration of the polyamide resin. That is, when the terminal amino group concentration of the polyamide resin is in the above-mentioned relatively high range, the oxygen absorption rate is suppressed to a value of almost zero or near zero,
When the terminal amino group concentration of the polyamide resin becomes lower than the above range, the oxygen absorption rate of the polyamide resin tends to increase.

These polyamides should also have a molecular weight sufficient to form a film and have a relative viscosity (ηrel) measured in concentrated sulfuric acid at a concentration of 1.0 g / dl and at a temperature of 30 ° C.
Is preferably 1.1 or more, particularly 1.5 or more.

As the thermoplastic resin, a thermoplastic polyester such as polyethylene terephthalate derived from an aromatic dicarboxylic acid such as terephthalic acid or isophthalic acid and a diol such as ethylene glycol can be used. So-called gas barrier polyester may be used as the one having excellent gas barrier property. This gas barrier polyester has a terephthalic acid component (T) and an isophthalic acid component (I) in the polymer chain.
And T: I = 95: 5 to 5:95 in a molar ratio of 75:25 to 25:75, and an ethylene glycol component (E) and a bis (2-hydroxyethoxy) benzene component (BHE).
B) and E) BHEB = 99.999: 0.001 to 2.0: 98.0, especially in a molar ratio of 99.95: 0.05 to 40:60. As BHEB, 1,3-bis (2-hydroxyethoxy) benzene is preferable. The polyester should have at least a molecular weight sufficient to form a film, generally in a mixed solvent of phenol and tetrachloroethane in a weight ratio of 50:50,
0.3 to 2.8 dl / g, especially 0.4, measured at a temperature of 30 ° C
It is desirable to have an intrinsic viscosity [η] of ˜1.8 dl / g.

[Oxidizing Organic Component] The oxidizing organic component used in the present invention has a functional group at the side chain or terminal and is oxidizable. The oxidizable organic component preferably has an active carbon atom that facilitates the abstraction of hydrogen, and such an active carbon atom is not limited to this, but a carbon-carbon double bond is preferable. Examples include adjacent carbon atoms, tertiary carbon atoms having a carbon side chain bonded thereto, and active methylene groups. On the other hand, examples of the functional group existing on the side chain or terminal include a carboxylic acid group, a carboxylic acid anhydride group, a carboxylate group, a carboxylic acid ester group, a carboxylic acid amide group, a carbonyl group, and a hydroxyl group.

As the oxidizing organic component, it is preferable to use a polyene oligomer or polymer modified with an acid or an acid anhydride. As the polyene, a polyene having 4 to 20 carbon atoms, or an oligomer or polymer containing a unit derived from a chain or cyclic conjugated or non-conjugated polyene is preferably used. Examples of these monomers include conjugated dienes such as butadiene and isoprene; 1,4-hexadiene, 3-methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4 -Chain non-conjugated dienes such as hexadiene, 4,5-dimethyl-1,4-hexadiene, 7-methyl-1,6-octadiene; methyltetrahydroindene, 5-ethylidene-2-norbornene, 5-methylene-2- Norbornene, 5-isopropylidene-2-norbornene, 5-vinylidene-2-norbornene, 6-chloromethyl-5-isopropenyl
-2-Norbornene, cyclic non-conjugated dienes such as dicyclopentadiene; 2,3-diisopropylidene-5-norbornene, 2
-Ethylidene-3-isopropylidene-5-norbornene, 2-
Trienes such as propenyl-2,2-norbornadiene, chloroprene and the like can be mentioned.

These polyenes are incorporated in the form of homopolymers, random copolymers, block copolymers, etc., alone or in combination of two or more kinds, or in combination with other monomers. As the monomer used in combination with the polyene, α-olefin 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-Eikosen, 9-
Methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1
-Tetradecene may be mentioned, and other monomers such as styrene, vinyltoluene, acrylonitrile, methacrylonitrile, vinyl acetate, methyl methacrylate, ethyl acrylate may be used.

Specific examples of the polyene polymer include:
Polybutadiene (BR), polyisoprene (IR), butyl rubber (IIR), natural rubber, nitrile-butadiene rubber (NBR), styrene-butadiene rubber (SB
R), chloroprene rubber (CR), ethylene-propylene-diene rubber (EPDM), and the like, but 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 vinylene group or in the side chain in the form of vinyl group.

It is preferable that these polyene polymers have a carboxylic acid group, a carboxylic acid anhydride group or a hydroxyl group introduced therein. Examples of the monomer used for introducing 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 their derivatives. Specifically, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid. Α, β-unsaturated carboxylic acids such as acids, bicyclo [2,2,2]
1] Unsaturated carboxylic acids such as hept-2-ene-5,6-dicarboxylic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, and other α, β unsaturated carboxylic acid anhydrides, bicyclo An anhydride of an unsaturated carboxylic acid such as [2,2,1] hept-2-ene-5,6-dicarboxylic acid anhydride may be mentioned.

The acid modification of the polyene polymer is carried out by using a resin having a carbon-carbon double bond as a base polymer, and graft-copolymerizing an unsaturated carboxylic acid or its derivative with this base polymer by a means known per se. 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 is an unsaturated carboxylic acid or its derivative, which can be used as
It is preferable that the content is 01 to 10% by weight. When the content of the unsaturated carboxylic acid or the derivative thereof is within the above range, the acid-modified polyene polymer is well dispersed in the thermoplastic resin, and oxygen is smoothly absorbed. Also, a hydroxyl group-modified polyene polymer having a hydroxyl group at the terminal can be favorably used.

The polyene polymer used in the present invention is 40
The viscosity at 0 ° 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 includes iron, cobalt, nickel, etc.
Group VIII metal components are preferred, but other Group I metals such as copper and silver: Group IV metals such as tin, titanium and zirconium, Group V vanadium, Group VI such as chromium, Group VII such as manganese. Mention may be made of the group metal components. 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 acid salt or organic acid salt or complex salt of the above transition metal. Examples of the inorganic acid salt 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 carboxylates, sulfonates, phosphonates, etc., and the carboxylates are suitable for the purpose of the present invention, and specific examples thereof include acetic acid, propionic acid, and isopropion. Acid, butanoic acid, isobutanoic acid, pentanoic acid, isopentanoic acid, hexanoic acid, heptanoic acid, isoheptanoic acid, octanoic acid, 2
-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, Tsuzu Examples thereof include 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 transition metal complex, a complex with β-diketone or β-keto acid ester is used, and β-diketone or β-ketone is used.
Examples of the keto acid ester 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, di Stearoylmethane, acetylacetone, stearoylacetone, bis (cyclohexanoyl) -methane, dipivaloylmethane and the like can be used.

[Resin Composition] The resin composition of the present invention preferably contains the oxidizing organic component in an amount of 0.01 to 10% by weight, particularly 1.0 to 7% by weight.
Further, in this resin composition, the transition metal catalyst is at least 300 ppm in terms of metal amount, particularly 310 to 80
It is preferably contained in an amount of 0 ppm.

When the amount of the oxidizing organic component is below the above range, the oxygen absorption tends to be lower than when it is within the above range, while when the amount of the oxidizing organic component is above the above range. In terms of oxygen absorbability, there is no particular advantage, and the strength and gas barrier properties of the resin composition tend to deteriorate, and moldability tends to deteriorate, which is not preferable. Further, when the amount of the transition metal catalyst is less than the above range, oxygen absorption tends to be lower than when it is within the above range, while when the amount exceeds the above range, the resin composition tends to deteriorate. Is also unfavorable because it increases.

Various means can be used for blending the oxidizable organic component and the transition metal catalyst with the thermoplastic resin. There is no particular order in this formulation and blending may be done in any order. For example, a blend of the two can be easily prepared by dry blending or melt blending the oxidizable polymer with the thermoplastic resin.
On the other hand, since the transition metal catalyst is a small amount compared to the thermoplastic resin and the oxidizing organic component, in order to perform the blending uniformly,
Generally, it is preferable to dissolve the transition metal catalyst in an organic solvent, mix the solution with a powdery or granular thermoplastic resin or further with an oxidizing organic component, and, if necessary, dry the mixture under an inert atmosphere.

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

The mixing of the thermoplastic resin, the oxidizing organic component and the transition metal catalyst, and the subsequent storage are preferably carried out in a non-oxidizing atmosphere so as to prevent oxidation in the previous stage of the composition. 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 pre-stage of the molding process using a vent type or an extruder or a dryer equipped with a dryer. Further, a masterbatch of a thermoplastic resin and / or an oxidizing organic component containing a transition metal catalyst in a relatively high concentration is prepared, and this masterbatch is dry blended with an unblended thermoplastic resin to obtain an oxygen of the present invention. An absorbent resin composition can also be prepared. When a polyamide resin is used as the thermoplastic resin in the present invention, it is dried at a temperature of 120 to 180 ° C., which is a general drying condition, under a reduced pressure of 0.5 to 2 mmHg for 2 to 6 hours, and then molded as described below. Good to use for.

The oxygen absorbing layer used in the present invention may optionally contain an activator known per se, though it is not generally required. Suitable examples of activators include, but are not limited to, polyethylene glycol, polypropylene glycol, ethylene vinyl alcohol copolymer,
Ethylene / methacrylic acid copolymers, polymers containing hydroxyl groups and / or carboxyl groups such as various ionomers. These hydroxyl group- and / or carboxyl group-containing polymers can be added 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 thermoplastic resin. The oxygen absorbing layer used in the present invention includes a filler, a colorant, a heat resistance stabilizer, a weather resistance stabilizer, an antioxidant, an antiaging agent, a light stabilizer, an ultraviolet absorber, an antistatic agent, a metal soap and a wax. Known resin compounding agents such as lubricants and modifying resins or rubbers can be compounded according to a method known per se. For example, the incorporation of the lubricant improves the penetration of the resin into the screw. Lubricants include metal soaps such as magnesium stearate and calcium stearate, hydrocarbon-based ones such as liquid, natural or synthetic paraffin, microwax, polyethylene wax, chlorinated polyethylene wax, and fatty acid-based ones such as stearic acid and lauric acid. , Stearic acid amide, valmitic acid amide, oleic acid amide, esylic acid amide, methylene bisstearamide, fatty acid monoamide type or bisamide type such as ethylene bisstearamide, butyl stearate, hydrogenated castor oil, ethylene Ester-based ones such as glycol monostearate, alcohol-based ones such as cetyl alcohol and stearyl alcohol,
And their mixed systems are commonly used. The amount of the lubricant added is appropriately in the range of 50 to 1000 ppm based on the thermoplastic resin.

In the resin composition of the present invention, after melt blending, the thermoplastic resin exists as a continuous phase (matrix) and the oxidizing organic component as a dispersed phase. The minimum length of the oxidizing organic component as the dispersed phase is preferably 400 nm or less from the viewpoint of oxygen absorption and moldability. The minimum length of the dispersion means the length of the portion where the distance between the parallel straight lines is the narrowest when sandwiched so as to contact the dispersion by two parallel straight lines. That is, if the dispersed particle size exceeds the above range, it is not preferable because the oxygen absorbability is lowered as compared with the case where it is within the above range, and it is also undesirable from the viewpoint of moldability and transparency.

[Multilayer Packaging Material] In the present invention, at least one layer of the above resin composition is optionally combined with at least one layer of another resin layer to form a cup, tray, bottle,
It is used as a packaging material for tube containers and lids.
Generally, the layer of the oxygen-absorbing resin composition is preferably provided inside the outer surface of the container or the like so as not to be exposed to the outer surface of the container or the like, and for the purpose of avoiding direct contact with the contents. It is preferably provided outside the inner surface of the container or the like. Thus, it is desirable to provide the oxygen-absorbing resin composition layer as at least one intermediate layer of the multilayer packaging material.

In the case of a multi-layered packaging material, examples of the other resin layer to be combined with the oxygen absorbing layer include moisture resistant resin such as olefin resin and thermoplastic polyester resin, gas barrier resin and the like. As an olefin resin,
Low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), linear ultra low density polyethylene (LVLDPE), and other polyethylene (PE),
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. Further, as the thermoplastic polyester resin, polyethylene terephthalate (PET), polybutylene terephthalate (PB)
T), polyethylene naphthalate (PEN), copolymerized polyesters thereof, and blended products thereof. Further, the most suitable example of the gas barrier resin is ethylene-vinyl alcohol copolymer (EVOH), and the ethylene content is, for example, 20 to 60 mol%, particularly 25 to 50 mol%. The ethylene-vinyl acetate copolymer has a saponification degree of 96.
A saponified product of a copolymer obtained by saponification so as to have a 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 30 ° C. in a mixed solvent of 85:15 by weight of phenol: water.
It is desirable to have a viscosity of 0.01 dl / g or more, especially 0.05 dl / g or more as measured by. Furthermore, as another example of the barrier resin, a cyclic olefin copolymer (CO
C), especially a copolymer of ethylene and a cyclic olefin, especially APEL manufactured by Mitsui Chemicals, Inc. can be used.

A suitable example of the laminated structure is as follows, where the layer of the oxygen-absorbing resin composition (hereinafter simply referred to as the oxygen-absorbing layer) is represented as OAR. Further, which layer is to be 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, four-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, seven-layer structure: PET / OAR / COC / PET / EVOH
/ OAR / PET, etc.

In the production of the above laminated body, an adhesive resin may be interposed between the resin layers, if necessary. As such an adhesive resin, a carbonyl (—CO—) group based on a carboxylic acid, a carboxylic anhydride, a carboxylic acid salt, a carboxylic acid amide, a carboxylic acid ester or the like is used in a main chain or a side chain of 1 to 700 mm. Equivalent (meq) / 1
There may be mentioned thermoplastic resins which are contained in a concentration of 00 g resin, especially 10 to 500 meq / 100 g resin. Suitable examples of adhesive resins include ethylene-acrylic acid copolymers, ion-crosslinked olefin copolymers, maleic anhydride grafted polyethylenes, maleic anhydride grafted polypropylenes, acrylic acid grafted polyolefins, ethylene-vinyl acetate copolymers, copolymers. One or a combination of two or more such as polymerized polyester and copolymer thermoplasticity. These resins are useful for lamination by coextrusion or sandwich lamination. In addition, for the adhesive lamination of the preformed gas barrier resin film and the moisture resistant resin film,
Thermosetting adhesive resins such as isocyanate type or epoxy type are also used.

In the multilayer packaging material of the present invention, the thickness of the oxygen absorbing layer is not particularly limited, but is generally 1 to 100 μm.
m, particularly preferably in the range of 5 to 50 μm. That is, if the thickness of the oxygen absorption layer is thinner than a certain range, the oxygen absorption performance is poor, and even if it is thicker than a certain range, there is no particular advantage in terms of the oxygen absorption property, and the amount of resin is increased, which is economical. This is because it is disadvantageous in terms of container characteristics such as flexibility of the material and deterioration of flexibility.

In the multi-layer packaging material of the present invention, the total thickness is generally 30 to 70, though it varies depending on the use.
00 μm, especially 50 to 5000 μm,
On the other hand, the thickness of the oxygen-absorbing intermediate layer is preferably 0.5 to 95%, especially 1 to 50% of the total thickness.

The multilayer packaging material of the present invention can be manufactured by a method known per se except that the oxygen absorbing layer is used. For example, for forming a film, a sheet or a tube, after melt-kneading the resin composition with an extruder,
The film is extruded into a predetermined shape through a T-die, a circular die (ring die) or the like to obtain a T-die method film, blown film or the like. The T die film is biaxially stretched to form a biaxially stretched film. Further, the resin composition is melt-kneaded by an injection machine and then injected into an injection mold to produce a container or a preform for producing the container. Furthermore, extruding the resin composition through a extruder into a molten resin mass,
By compression-molding this with a mold, a container and a preform for manufacturing the container are manufactured. The molded product may be in the form of a film, a sheet, a parison or pipe for forming a bottle or a tube, a preform for forming a bottle or a tube, or the like. The formation of a bottle from a parison, pipe or preform is facilitated by pinching off the extrudate with a pair of split molds and blowing a fluid into it. Further, after cooling the pipe or preform, it is heated to a stretching temperature, supplied into a stretch blow molding machine, set in a mold, stretched in the axial direction by pushing a stretch rod, and By stretching in the circumferential direction, a stretch blow bottle or the like can be obtained. The stretch-blow-molded bottle can be heat-set by a means known per se, and the heat-setting can be performed in a blow-molding die by the one-mold method, or by a two-mold method. It is also possible to use a heat fixing mold separate from the above. As another stretch blow molding, Japanese Patent No. 2917 relating to the applicant of the present application
As illustrated in Japanese Patent No. 851, a pipe or a preform is made into a primary blow molded product having a size larger than that of a final blow mold molded product by using a primary blow mold, and then this primary blow molded product is heat-shrinked. After that, a two-stage stretch blow-molded body that is subjected to biaxial stretch blow-molding using a secondary blow mold to obtain a final blow-molded body can be mentioned. According to this stretch blow molding, the bottom portion can be sufficiently stretched and thinned, and a stretch blow molded article excellent in impact resistance and deformation of the bottom portion during hot filling and heat sterilization can be obtained. Furthermore, by further applying the film or sheet to a means such as vacuum forming, pressure forming, overhang forming, and plug assist forming, a cup shape,
A tray-like packaging container or a lid material made of a film or a sheet can be obtained.

A packaging material such as a film can be used as a packaging bag in various forms, and the bag can be produced by a bag-making method known per se. Ordinary pouches with three-sided or four-sided seals, Examples thereof include gusseted pouches, standing pouches, and pillow packaging bags, but are not limited to these examples.

For producing the multi-layer extrusion molded article, a co-extrusion molding method known per se can be used. For example, the number of extruders corresponding to the kind of the resin is used and the multi-layer multiple die is used as described above. Extrusion molding may be performed in the same manner. Further, in the production of the multilayer injection-molded article, the number of injection molding machines corresponding to the type of resin can be used to produce the multilayer injection-molded article by the co-injection method or the sequential injection method. Further, an extrusion coating method or sandwich lamination can be used for producing the multilayer film or sheet, and the multilayer film or sheet can be produced by dry lamination of a preformed film.

The multi-layer packaging material of the present invention is useful as a container capable of preventing the flavor of the contents from being deteriorated due to oxygen. Contents that can be filled include beer, wine, fruit juice, carbonated soft drinks for beverages, fruits for food,
Nuts, vegetables, meat products, infant foods, coffee, jams,
Mayonnaise, ketchup, edible oil, dressing, sauces, boiled dairy products, etc.
Examples include content items such as gasoline that are prone to deterioration in the presence of oxygen, but are not limited to these examples.

[0059]

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

[Measurement of Oxygen Permeation Amount of Multilayer Film] High Retoflex (HR78-8) in a cup-shaped container having an inner volume of 60 ml.
1 cc of water was placed in a 4W steel foil / polypropylene laminated container manufactured by Toyo Seikan Co., Ltd., and heat-sealed in a nitrogen atmosphere with the multilayer film as a lid material. These cups at 95 ℃
Boiled for 30 minutes, stored at 30 ° C-80% RH, and subjected to gas chromatography (GC-8AIT, GC-
3BT: Both manufactured by Shimadzu Corporation, detector: TCD (1
00 ° C), column: molecular sieve 5A (60
C), carrier gas: argon) was used to measure the oxygen concentration in the cup. From this oxygen concentration, the amount of oxygen permeation was calculated.

[Dissolved Oxygen Concentration in Multi-Layer Bottle] A multi-layer bottle was filled with oxygen-free water while flowing nitrogen gas into the bottle and sealed with an aluminum cap without mixing air bubbles. Store these multi-layer bottles at 55 ° C as they are and use them to measure dissolved oxygen concentration in water (oxygen indicator: orbisphere labor
The concentration of dissolved oxygen in the water filled in the multi-layer bottle was measured using atories).

[Dispersion Observation of Unsaturated Double Bond Polymer in Thermoplastic Resin] Multilayer film, width 2 mm from multilayer bottle,
A sample piece having a length of 12 mm was cut out and embedded in an epoxy resin with a mold made of silicon and hardened. After the cross section of the sample piece was exposed by a microtome, only the exposed part was stirred and washed with chloroform (special grade for high-performance liquid chromatography: manufactured by Kishida Chemical Co., Ltd.) for 1 hour and dried for 1 hour in vacuum.
Pretreatment was performed by depositing Pt at 10 mA for 10 minutes. Scanning electron microscope (JSM-6300F: manufactured by JEOL Ltd.) with an accelerating voltage of 1
The cross section of the sample piece pretreated with 0 kV was observed.

Example 1 A thermoplastic resin having a solubility index (Sp value) of 11.6 and a terminal amino group concentration of 87 eq.
/ 10 ⁶ g of polymeta-xylylene adipamide (MXD6) resin (T-600: manufactured by Toyobo Co., Ltd.), cobalt neodecanoate (DICANATE5) having a cobalt content of 14% as a transition metal catalyst
000: Mixed by a tumbler using Dainippon Ink and Chemicals Co., Ltd., and cobalt neodecanoate was deposited on the MXD6 surface at 400 ppm in cobalt amount. Then, using a liquid feeder, while dropping maleic acid-modified polybutadiene (M-2000-20: manufactured by Nippon Petrochemical Co., Ltd.) as an oxidizing organic component, 37 m of MXD6 resin to which cobalt was adhered was added.
Extruded from a twin-screw extruder with a built-in m diameter screw,
An oxygen-absorbing resin composition containing 400 ppm of cobalt neodecanoate in a cobalt amount and 5% by weight of maleic acid-modified polybutadiene was obtained. This resin composition was supplied to a T-die extruder to form an oxygen-absorbing film having a thickness of 20 μm at a molding temperature of 260 ° C. The above films were laminated with a multi coater to prepare a multilayer film having a structure of 12 μm PET / 20 μm oxygen absorbing film / 50 μm PP. Use the above-mentioned multilayer film as a lid material and seal a cup
The sample was boiled at 5 ° C. for 30 minutes, and the amount of oxygen permeated into the container after 30 days of storage at 30 ° C. and 80% RH was measured. Further, the film-forming property of the oxygen-absorbing film was confirmed, the minimum length of the dispersion and the oxygen permeation amount were measured, and the results are shown in Table 1.

Comparative Example 1 An oxygen-absorbing film was formed under the same conditions as in Example 1, except that polybutadiene (B-2000: manufactured by Nippon Petrochemical Co., Ltd.) was used as the oxidizing organic component. The film could not be formed. The results are shown in Table 1.

[Comparative Example 2] Polypropylene (PP) having a solubility index of 7.9 as a thermoplastic resin (Nobak PPFG3D,
An oxygen-absorbing film and a multilayer film were prepared in the same manner as in Example 1 except that the molding temperature was 230 ° C. using Nippon Polychem Co., Ltd., and the same confirmation and measurement were performed. The results are shown in Table 1.

[Comparative Example 3] As a thermoplastic resin, polyethylene (PE) having a solubility index of 8.0 (Sumikasen L70) was used.
5. Using Sumitomo Chemical Co., Ltd., an oxygen absorbing film and a multilayer film were prepared in the same manner as in Example 1 except that the molding temperature was 180 ° C., and the same confirmation and measurement were performed. The results are shown in Table 1.

[0067]

[Table 1]

[Example 2] Polyethylene terephthalate (PET) (J-125T, manufactured by Mitsui Chemicals, Inc.) was used as an inner / outer layer injection machine from MXD6 prepared in Example 1, cobalt neodecanoate, and maleic acid-modified polybutadiene. The following resin composition is supplied to the injection machine for the intermediate layer, the injection nozzle temperature is 280 ° C., and the resin pressure is 250 kgf / cm ^{2 under} the conditions of co-injection molding in an injection mold. Example 1
The oxygen-absorbing resin composition used in 2 above was formed into a 2-kind 3-layer preform having a basis weight of 32 g and an intermediate layer volume ratio of 6%. This preform has a glass transition point of PET 1 or higher.
Biaxially stretch blow molding was carried out in a mold heated to 10 ° C. and heated to 150 ° C. to obtain a two-kind three-layer multilayer bottle having an inner volume of 500 ml. The moldability of the multilayer preform and the multilayer bottle was confirmed, the minimum length of the dispersion and the dissolved oxygen concentration in the multilayer bottle after storage at 55 ° C. for 28 days were measured. The results are shown in Table 2.

Example 3 As a thermoplastic resin, ethylene-vinyl alcohol copolymer (EVOH) (EPOH) having a solubility index of 11.1 and an ethylene content of 32 mol% was used.
-F101B: A multi-layer preform and a multi-layer bottle were prepared in the same manner as in Example 2 except that the same product was used, and the same confirmation and measurement were performed. The results are shown in Table 2.

[Example 4] As a thermoplastic resin, polyethylene terephthalate (P having a solubility index of 10.7) was used.
ET) (J-125T: manufactured by Mitsui Chemicals, Inc.) was used to prepare a multi-layer preform and a multi-layer bottle in the same manner as in Example 2, and the same confirmation and measurement as in Example 2 were performed. The results are shown in Table 2.

[Example 5] As a thermoplastic resin, a solubility index of 10.7 barrier copolymerized polyester (B
-Resin: A multi-layer preform and a multi-layer bottle were prepared in the same manner as in Example 2 except that a resin was used, and the same confirmation and measurement were performed. The results are shown in Table 2.

Comparative Example 4 A multilayer preform was molded in the same manner as in Example 2 except that the polybutadiene was used as the oxidizing organic component, but a satisfactory preform was not obtained, and a multilayer bottle was also obtained. There wasn't. The results are shown in Table 2.

[Comparative Example 5] The transition metal-based catalyst was cobalt neodecanoate in an amount of 200 ppm in cobalt, and the oxidizing organic component was hydroxyl group-modified polybutadiene (R-45HT:
A multilayer preform was molded in the same manner as in Example 2 except that Idemitsu Petrochemical Co., Ltd.) was used, but a satisfactory preform was not obtained, and a multilayer bottle was not obtained. The results are shown in Table 2.

[0074]

[Table 2]

[0075]

According to the present invention, (A) the solubility index (S
(p value) 9.5 or more and melt-extrudable thermoplastic resin, (B) side chain or functional group-containing and oxidizable organic component, and (C) transition metal catalyst By having a resin composition, while having excellent oxygen absorption,
The advantage that oxygen permeation through the resin layer can be reduced for a long period of time and that the moldability and mechanical strength are excellent is achieved. Further, by forming a packaging material with the layer of the resin composition, the layer of the resin composition is excellent in oxygen absorption, and the resin layer itself also has excellent oxygen barrier properties and strength. Benefits are obtained.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08K 3/10 C08K 3/10 C08L 29/04 C08L 29/04 S 67/00 67/00 77/00 77 / 00 // (C08L 101/00 C08L 13:00 13:00) (72) Inventor Toshiki Yamada 22 No. 4 Okazawa-cho Hodogaya-ku, Yokohama-shi, Kanagawa 4 Toyo Seikan Group Integrated Research Center F-term (reference) 3E067 AA03 AA11 AB01 AB26 BA03A BB14A BB22A CA06 EE25 EE32 EE33 FA01 FC01 4F071 AA11 AA11X AA12 AA12X AA13 AA13X AA15X AA29X AA32X AA36X AA43 AA54 AA77 AB15 AB19 AC07 AC09 AC10 AF08 AH04 AH05 4F100 AK01A AK01B AK01C AK02A AK07 AK08 AK42 AK46A AK46J AK51A AK51J AK69A AK79J AL01A AL07A BA03 BA07 BA10B BA10C GB15 JB16A JD02 JD04B JD04C YY00A 4J002 AC022 AC102 BB221 BE031 BN062 BN132 BN142 CF041 CF061 CL011 CL031 DD076 DF036 DG046 DH036 DJ00 6 EE046 EG046 EG076 FD202 FD206 GF00 GG01 GG02

Claims (9)

[Claims] 1. A thermoplastic resin having a solubility index (Sp value) of 9.5 or more and capable of being melt-extruded, an organic component having a functional group at a side chain or a terminal and capable of being oxidized, and a transition metal catalyst. A resin composition excellent in moldability and gas barrier property, which is characterized by containing. 2. The resin composition according to claim 1, wherein the thermoplastic resin is present as a continuous phase and the oxidizable organic component is present as a dispersed phase. 3. A thermoplastic resin comprising at least one resin selected from the group consisting of an ethylene-vinyl alcohol copolymer, a polyamide or its copolymer, and a polyester. The resin composition described. 4. The resin composition according to claim 1, wherein the oxidizable organic component comprises a polyene oligomer or polymer modified with an acid or an acid anhydride. 5. The oxidizable organic component is dispersed in a thermoplastic resin with a dispersed particle diameter having a minimum length of 400 nm or less, according to any one of claims 1 to 4. Resin composition. 6. The resin according to claim 1, wherein the transition metal catalyst is an organic salt of at least one metal selected from the group consisting of cobalt, manganese, copper and iron. Composition. 7. The resin composition contains 0.0 or more oxidizing organic components.
It is present in an amount of 1 to 10% by weight, and based on the total amount thereof, the transition metal catalyst has a metal content of at least 300 p.
The resin composition according to claim 1, wherein the resin composition is present in an amount of pm. 8. A packaging material having excellent moldability and gas barrier properties, which has at least one layer made of the resin composition according to any one of claims 1 to 7. 9. The packaging material according to claim 8, wherein the layer is an intermediate layer, and further has an inner layer and an outer layer made of a moisture resistant resin.