JP2015034226A - Oxygen-absorbing polyamide resin composition and multilayer molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxygen-absorbing polyamide resin composition which achieves both oxygen barrier performance and oxygen absorbing performance, suppresses deterioration in hue and strength as oxygen absorption progresses and maintains excellent barrier properties for a long period of time even after thermal sterilization, and to provide a multilayer molded body.SOLUTION: There is provided a polyamide resin composition obtained by melt-mixing an oxygen-absorbing resin composition (A) containing an oxygen-absorbing resin (A1) composed of a cyclized conjugated diene polymer and a polyamide resin (B), wherein the polyamide resin (B) contains a diamine unit containing 50 mol% or more of a specific aromatic diamine unit in total and a dicarboxylic acid unit containing 50 mol% or more of a specific linear aliphatic dicarboxylic acid unit and/or a specific aromatic dicarboxylic acid unit in total.

Description

  The present invention relates to a polyamide resin composition and a multilayer molded article having oxygen barrier performance and oxygen absorption performance.

  A polyamide obtained from a polycondensation reaction between xylylenediamine and an aliphatic dicarboxylic acid, for example, a polyamide obtained from metaxylylenediamine and adipic acid (hereinafter referred to as nylon MXD6) has high strength, high elastic modulus, and oxygen. It exhibits low permeability to gaseous substances such as carbon dioxide, odor and flavor. Therefore, it is widely used as a gas barrier material in the packaging material field. Nylon MXD6 has good thermal stability when melted compared to other gas barrier resins, so co-extrusion with thermoplastic resins such as polyethylene terephthalate (hereinafter abbreviated as PET), nylon 6 and polypropylene, Co-injection molding or the like is possible. Therefore, nylon MXD6 is actively used as a gas barrier layer constituting a multilayer structure.

  In recent years, a small amount of transition metal compound is added to nylon MXD6 and mixed to impart an oxygen absorbing function to nylon MXD6, which is used as an oxygen barrier material constituting a container or packaging material. Thereby, the functionalized nylon MXD6 absorbs oxygen permeating from the outside of the container, and the functionalized nylon MXD6 also absorbs oxygen remaining inside the container. In this way, a method for improving the storage stability of the contents over containers using conventional oxygen-barrier thermoplastic resins is being put into practical use (see, for example, Patent Documents 1 and 2).

  On the other hand, oxygen absorbers have been used for a long time to remove oxygen in the container. For example, Patent Documents 3 and 4 describe an oxygen-absorbing multilayer body and an oxygen-absorbing film in which an oxygen absorbent such as iron powder is dispersed in a resin. Patent Document 5 describes a product having an oxygen scavenging layer containing an ethylenically unsaturated compound such as polybutadiene and a transition metal catalyst such as cobalt, and an oxygen barrier layer such as polyamide. Further, a resin composition is disclosed in which a conjugated diene polymer cyclized product having a very high oxygen absorption capacity is dispersed in a matrix such as ethylene-vinyl alcohol copolymer (EVOH) (see, for example, Patent Document 6). ).

JP 2003-341747 A Japanese Patent No. 2991437 JP-A-2-72851 Japanese Patent Laid-Open No. 4-90848 Japanese Patent Laid-Open No. 5-115776 International Publication No. 2007/094247

Oxygen-absorbing multilayers and oxygen-absorbing films in which an oxygen absorbent such as iron powder is dispersed in the resin are opaque because the resin is colored by the oxygen absorbent such as iron powder. There is an application restriction that it cannot be used in the field.
On the other hand, a resin composition containing a transition metal such as cobalt has an advantage that it can be applied to packaging containers that require transparency, but is not preferred because the resin composition is colored by a transition metal catalyst. In a resin composition containing a transition metal, the resin absorbs oxygen by the transition metal catalyst, and the resin is oxidized. Specifically, it is considered as follows. When nylon MXD6 contains a transition metal, it is considered that a hydrogen atom is extracted from the methylene chain adjacent to the arylene group of the polyamide resin by the transition metal atom. It is considered that a radical is generated due to the extraction of a hydrogen atom and a peroxy radical is generated by adding an oxygen molecule to the radical. It is considered that oxidation of the resin occurs by each reaction such as extraction of a hydrogen atom by a peroxy radical. Since the resin is oxidized by oxygen absorption by such a mechanism, a decomposition product is generated and an unpleasant odor is generated in the contents of the container, or the color tone, strength, etc. of the container are impaired due to oxidative degradation of the resin. There was a problem.
In particular, in packaging containers that are subjected to heat sterilization such as boil processing and retort processing, there is a problem that the color tone and strength of the container are reduced due to oxidative degradation of the resin after the heat sterilization processing. Decreased. Furthermore, ethylene vinyl alcohol copolymer (EVOH), which has a large shock due to heat sterilization treatment, causes a rapid deterioration of the barrier properties during and after the heat sterilization treatment, and sufficient barrier performance even if oxygen absorption is imparted. There was a problem that could not be demonstrated.

  An object of the present invention is to achieve both an oxygen barrier performance and an oxygen absorption performance, to suppress a decrease in color tone and strength as oxygen absorption proceeds, and to provide excellent barrier properties for a long time even after heat sterilization treatment. It is to provide an oxygen-absorbing polyamide resin composition and a multilayer molded body to be maintained.

［前記一般式（II）中、ｎは２〜１８の整数を表す。前記一般式（III）中、Ａｒはアリーレン基を表す。］
以下、上記構成の本発明の酸素吸収性ポリアミド樹脂組成物を、「酸素吸収性ポリアミド樹脂組成物（Ｃ）」、又は、単に「組成物（Ｃ）」と称する。
＜２＞ 前記酸素吸収性ポリアミド樹脂組成物を含有する層（Ｘ）と、少なくとも一種の樹脂（Ｄ）を主成分とする層（Ｙ）との少なくとも２層を有する、多層成形体。 The present invention provides the following polyamide resin composition and multilayer molded article.
<1> An oxygen-absorbing polyamide resin composition obtained by melt-mixing an oxygen-absorbing resin composition (A) containing an oxygen-absorbing resin (A1) composed of a conjugated diene polymer cyclized product and a polyamide resin (B). Because
The polyamide resin (B) is a linear fat represented by the following general formula (II) and a diamine unit containing at least one aromatic diamine unit represented by the following general formula (I) in a total amount of 50 mol% or more: Oxygen-absorbing polyamide resin composition containing an aromatic dicarboxylic acid unit and / or a dicarboxylic acid unit containing 50 mol% or more of the aromatic dicarboxylic acid unit represented by the following general formula (III).

[In said general formula (II), n represents the integer of 2-18. In the general formula (III), Ar represents an arylene group. ]
Hereinafter, the oxygen-absorbing polyamide resin composition of the present invention having the above constitution is referred to as “oxygen-absorbing polyamide resin composition (C)” or simply “composition (C)”.
<2> A multilayer molded article having at least two layers of a layer (X) containing the oxygen-absorbing polyamide resin composition and a layer (Y) containing at least one kind of resin (D) as a main component.

According to the present invention, the oxygen barrier performance and the oxygen absorption performance are compatible, the color tone and the strength are suppressed from decreasing as the oxygen absorption progresses, and excellent barrier properties are obtained even after the heat sterilization treatment for a long period of time. An oxygen-absorbing polyamide resin composition and a multilayer molded body to be maintained can be provided.
The container formed of the multilayer molded article is excellent in suppressing the oxidative deterioration of the contents, hardly generating substances that cause a strange odor and flavor change, and excellent in flavor retention.

<< Oxygen-absorbing resin composition (A) >>
The oxygen-absorbing resin composition (A) used in the present invention contains an oxygen-absorbing resin (A1) made of a conjugated diene polymer cyclized product.

The oxygen-absorbing resin (A1) used in the present invention comprises a conjugated diene polymer cyclized product.
The conjugated diene polymer cyclized product can be obtained, for example, by subjecting a conjugated diene polymer to a cyclization reaction in the presence of an acid catalyst.
Conjugated diene polymers include homopolymers of conjugated diene monomers, copolymers of different conjugated diene monomers, and conjugated diene monomers that can be copolymerized with conjugated diene monomers. Copolymers with “monomers other than monomers” (referred to as other monomers) can be used.
The conjugated diene monomer is not particularly limited, and specific examples thereof include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1, Examples include 3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, and 3-butyl-1,3-octadiene. These conjugated diene monomers may be used alone or in combination of two or more.

Examples of other monomers copolymerizable with the conjugated diene monomer include styrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, and p-tert. Aroma such as butyl styrene, α-methyl styrene, α-methyl-p-methyl styrene, o-chloro styrene, m-chloro styrene, p-chloro styrene, p-bromo styrene, 2,4-dibromo styrene, vinyl naphthalene Group vinyl monomers; chain olefin monomers such as ethylene, propylene, 1-butene; cyclic olefin monomers such as cyclopentene, 2-norbornene; 1,5-hexadiene, 1,6-heptadiene, 1, Non-conjugated diene monomers such as 7-octadiene, dicyclopentadiene, 5-ethylidene-2-norbornene; Methyl Le acid, (meth) (meth) acrylic acid esters such as ethyl acrylate; (meth) acrylonitrile, and other (meth) acrylic acid derivatives such as (meth) acrylamide; and the like.
These other monomers may be used alone or in combination of two or more.

  Specific examples of the conjugated diene polymer include natural rubber (NR), styrene-isoprene rubber (SIR), styrene-butadiene rubber (SBR), polyisoprene rubber (IR), polybutadiene rubber (BR), isoprene-isobutylene copolymer Examples thereof include a combined rubber (IIR), an ethylene-propylene diene copolymer rubber (EPDM), a butadiene-isoprene copolymer rubber (BIR), a styrene-isoprene block polymer, and a styrene-butadiene block polymer. Among these, polyisoprene rubber, polybutadiene rubber, and styrene-isoprene block polymer are preferable, and polyisoprene rubber and styrene-isoprene block polymer are more preferable. These conjugated diene polymers may be used alone or in combination of two or more.

The content of the conjugated diene monomer unit in the conjugated diene polymer is appropriately selected within a range not impairing the effects of the present invention, but is usually 40 mol% or more, preferably 60 mol% or more, more preferably 80 mol. % Or more. When the content of the conjugated diene monomer unit is 40 mol% or more, it is easy to obtain an unsaturated bond reduction rate in an appropriate range described later.
The polymerization method of the conjugated diene polymer may be in accordance with a conventional method, for example, solution polymerization or emulsification using an appropriate catalyst such as a Ziegler polymerization catalyst, an alkyl lithium polymerization catalyst or a radical polymerization catalyst containing titanium as a catalyst component. A conjugated diene polymer may be polymerized by polymerization.

The conjugated diene polymer cyclized product used in the present invention can be obtained, for example, by subjecting the conjugated diene polymer to a cyclization reaction in the presence of an acid catalyst.
Known acid catalysts can be used for the cyclization reaction. Specific examples thereof include sulfuric acid, fluoromethanesulfonic acid, difluoromethanesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, alkylbenzenesulfonic acid having an alkyl group having 2 to 18 carbon atoms, anhydrides and alkyl esters thereof, and the like. Organic sulfonic acid compounds: boron trifluoride, boron trichloride, tin tetrachloride, titanium tetrachloride, aluminum chloride, diethylaluminum monochloride, ethylammonium chloride, aluminum bromide, antimony pentachloride, tungsten hexachloride, iron chloride, etc. And Lewis acid.
These acid catalysts may be used alone or in combination of two or more.
Among these, organic sulfonic acid compounds are preferable, and p-toluenesulfonic acid and xylenesulfonic acid are more preferable.
The usage-amount of an acid catalyst is 0.05-10 mass% normally per 100 mass% of conjugated diene polymers, Preferably it is 0.1-5 mass%, More preferably, it is 0.3-2 mass%. It is.

The cyclization reaction is usually performed by dissolving a conjugated diene polymer in a hydrocarbon solvent.
The hydrocarbon solvent is not particularly limited as long as it does not inhibit the cyclization reaction. For example, aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; n-pentane, n-hexane, n-heptane, Examples include aliphatic hydrocarbons such as n-octane; alicyclic hydrocarbons such as cyclopentane and cyclohexane.
Among these, hydrocarbon solvents having a boiling point of 70 ° C. or higher are preferable.
The solvent used for the polymerization reaction of the conjugated diene polymer and the solvent used for the cyclization reaction may be the same or different. When the polymerization reaction and the solvent for the cyclization reaction are the same species, an acid catalyst for the cyclization reaction can be added to the polymerization reaction solution after the completion of the polymerization reaction, and the cyclization reaction can be carried out following the polymerization reaction. .
The amount of the hydrocarbon solvent used is a range in which the solid content concentration of the conjugated diene polymer is usually 5 to 60% by mass, and preferably 20 to 40% by mass.

The cyclization reaction can be carried out under any pressure of pressure, reduced pressure and atmospheric pressure, but it is desirable to carry out under atmospheric pressure from the viewpoint of easy operation. When the cyclization reaction is performed in a dry air flow, particularly in an atmosphere of dry nitrogen or dry argon, side reactions caused by moisture can be suppressed.
The reaction temperature and reaction time in the cyclization reaction are not particularly limited. Reaction temperature is 50-150 degreeC normally, Preferably it is 70-110 degreeC. The reaction time is usually 0.5 to 10 hours, preferably 2 to 5 hours.
After carrying out the cyclization reaction, the acid catalyst is deactivated by a conventional method, the acid catalyst remaining is removed, and then the hydrocarbon solvent is removed to obtain a solid conjugated diene polymer cyclized product. .

In the present invention, in particular, when the conjugated diene polymer is cyclized, the value obtained by proton NMR analysis of the unsaturated bond reduction rate of the conjugated diene polymer cyclized product relative to the number of unsaturated bonds in the conjugated diene polymer is It is preferable to use a conjugated diene polymer cyclized product of 10% or more. By using a conjugated diene polymer cyclized product having an unsaturated bond reduction rate of 10% or more, generation of odor during oxygen absorption can be suppressed.
The unsaturated bond reduction rate of the conjugated diene polymer cyclized product is preferably 40 to 80%, more preferably 50 to 70%, and particularly preferably 55 to 65%.
The unsaturated bond reduction rate of the conjugated diene polymer cyclized product can be adjusted by appropriately selecting the amount of acid catalyst, reaction temperature, reaction time, and the like in the cyclization reaction. By appropriately setting the unsaturated bond reduction rate of the conjugated diene polymer cyclized product, the glass transition temperature of the oxygen-absorbing resin composition (A) can be in an appropriate range. As a result, excellent oxygen absorptivity is exhibited and the generation of odor during oxygen absorption can be suppressed. Occurrence of odor during oxygen absorption is suppressed when the unsaturated bond reduction rate of the conjugated diene polymer cyclized product is 10% or more. When the unsaturated bond reduction rate is 80% or less, it is easy to produce a conjugated diene polymer cyclized product, and embrittlement of the conjugated diene polymer cyclized product can be suppressed.

Here, the unsaturated bond reduction rate is an index representing the degree to which the unsaturated bond is reduced by the cyclization reaction in the conjugated diene monomer unit portion in the conjugated diene polymer, and is specifically as follows. It is a numerical value obtained by
Proton NMR analysis is performed on each of the conjugated diene polymer before the cyclization reaction and the cyclized product of the conjugated diene polymer obtained after the cyclization reaction. First, in the conjugated diene monomer unit portion in the conjugated diene polymer, the peak area [SBT] of all protons and the peak area [SBU] of protons directly bonded to double bonds are determined. In addition, in the conjugated diene monomer unit portion in the conjugated diene polymer cyclized product, the peak area [SAT] of all protons and the peak area [SAU] of protons directly bonded to the double bond are obtained.
Further, for the conjugated diene polymer and the conjugated diene polymer cyclized product, respectively, the ratio of the peak area of the proton directly bonded to the double bond to the peak area of all protons, that is, SBU / SBT and SAU / SAT, Calculate the rate of decrease.
Therefore, the peak area ratio (SB) of the proton directly bonded to the double bond before the cyclization reaction is
SB = SBU / SBT
The peak area ratio (SA) of the proton directly bonded to the double bond after the cyclization reaction is
SA = SAU / SAT
It is. Therefore, the unsaturated bond reduction rate of the conjugated diene polymer cyclized product can be obtained by the following formula.
Unsaturated bond reduction rate (%) = 100 × (SB−SA) / SB

The weight average molecular weight of the conjugated diene polymer cyclized product is a standard polystyrene conversion value measured by gel permeation chromatography (GPC), and is usually 1,000 to 1,000,000, preferably 10,000. It is -700,000, More preferably, it is 30,000-500,000.
The weight average molecular weight of the conjugated diene polymer cyclized product can be adjusted by appropriately selecting the weight average molecular weight of the conjugated diene polymer subjected to cyclization. By appropriately setting the weight average molecular weight of the conjugated diene polymer cyclized product, the moldability of the film and the sheet is good, and the mechanical strength is good. Further, the solution viscosity at the time of the cyclization reaction becomes appropriate, and the processability at the time of extrusion molding is kept good.

  The amount of the conjugated diene polymer cyclized product (toluene-insoluble component) is usually 10% by mass or less, preferably 5% by mass or less, but it is particularly preferable that the conjugated diene polymer cyclized product has substantially no gel. The fall of the smoothness of a film and a sheet | seat can be suppressed because a gel amount shall be 10 mass% or less.

  In addition to the conjugated diene polymer cyclized product [oxygen-absorbing resin (A1)], the oxygen-absorbing resin composition (A) may contain an antioxidant as necessary. However, the content of the antioxidant in the oxygen-absorbing resin composition (A) is usually 5000 ppm by mass or less from the viewpoint of suppressing the decrease in oxygen-absorbing capacity of the oxygen-absorbing resin composition (A). , Preferably it is 3000 mass ppm or less, More preferably, it is 500 mass ppm or less, Most preferably, it is substantially 0 ppm.

The antioxidant is not particularly limited as long as it is usually used in the field of resin materials or rubber materials. Representative examples of such antioxidants include hindered phenol-based, phosphorus-based and lactone-based antioxidants. These antioxidants may be used alone or in combination of two or more.
Specific examples of hindered phenol antioxidants include 2,6-di-t-butyl-p-cresol, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl). Propionate], thiodiethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N , N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionamide], diethyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] phosphonate, 3,3 ', 3 ", 5,5', 5" -hexa-t-butyl, a ', a "-(mesitylene-2,4,6-to Liyl) tri-p-cresol, hexamethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], tetrakis [methylene-3- (3,5-di-t-butyl- 4-hydroxyphenyl) propionate] methane, n-octadecyl-3- (4′-hydroxy-3,5′-di-t-butylphenyl) propionate, 1,3,5-tris (3,5-di-t -Butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,4-bis- (n-octylthio) -6- (4-hydroxy -3,5-di-t-butylanilino) -1,3,5-triazine, tris (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, 2-t-butyl-6- ( 3- -Butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1- (2-hydroxy-3,5-di-t-phenylbutyl) ethyl-4,6-di-t- Benzylphenyl acrylate] and the like.

  Phosphorus antioxidants include tris (2,4-di-t-butylphenyl) phosphite, bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl phosphite , Tetrakis (2,4-di-t-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite, bis (2,4-di-t-butylphenyl) pentaerythritol phosphite 4,4′-butylidenebis (3-methyl-6-tert-butylphenylditridecyl phosphite) and the like. In addition, a lactone antioxidant which is a reaction product of 5,7-di-t-butyl-3- (3,4-dimethylphenyl) -3H-benzofuran-2-one and o-xylene is used in combination. May be.

  In addition, the oxygen-absorbing resin composition (A) may contain various compounds that are usually added as necessary. Such compounds include fillers such as calcium carbonate, alumina, titanium oxide; tackifiers (hydrogenated petroleum resins, hydrogenated terpene resins, castor oil derivatives, sorbitan higher fatty acid esters, etc.); plasticizers (phthalate esters) , Glycol esters, etc.); surfactants; leveling agents; UV absorbers; light stabilizers; aldehyde adsorbents such as alkylamines and amino acids; dehydrating agents; pot life extenders (acetylacetone, methanol, methyl orthoacetate, etc.); Mention may be made of those commonly used for adhesives, such as improvers.

  The oxygen-absorbing resin composition (A) used in the present invention may contain a known oxygen-absorbing component in addition to the oxygen-absorbing resin (A1) as long as the effects of the present invention are not impaired. The amount of the oxygen-absorbing component other than the oxygen-absorbing resin (A1) is 50 mass relative to the total amount of the oxygen-absorbing component (total amount of the oxygen-absorbing resin (A1) and the other oxygen-absorbing components). % Is preferably less than 40%, more preferably less than 40% by mass, still more preferably less than 30% by mass.

The oxygen-absorbing resin composition (A) used in the present invention preferably further contains a softening agent (A2).
The softener (A2) preferably has compatibility with the oxygen-absorbing resin (A1). Moreover, it is preferable that the softening agent (A2) used in the present invention is capable of setting the glass transition temperature of the oxygen-absorbing resin composition (A) used in the present invention to 30 ° C. or less, and in particular, itself. It is preferably a liquid material having a glass transition temperature or a pour point of −30 ° C. or lower. The lower limit of the glass transition temperature of the oxygen-absorbing resin composition (A) composed of the oxygen-absorbing resin (A1) and the softening agent (A2) is preferably −30 ° C. When this glass transition temperature is too low, the amount of the softening agent (A2) is excessively increased and the oxygen absorption tends to be lowered.

  Specific examples of the softening agent (A2) include hydrocarbon oils such as isoparaffinic oil, naphthenic oil, and liquid paraffin; olefin polymers such as polybutene; hydrides of conjugated diene polymers such as polyisoprene and polybutadiene; styrene conjugates Examples thereof include hydrides of diene polymers. These softeners may be used alone or in combination of two or more. Among these, hydrocarbon oil and olefin polymer are preferable, and liquid paraffin and polybutene are particularly preferable.

When the oxygen-absorbing resin composition (A) contains the softening agent (A2), the ratio of the oxygen-absorbing resin (A1) and the softening agent (A2) is not particularly limited, but the obtained oxygen-absorbing resin composition The ratio is preferably such that the glass transition temperature of the product (A) is 30 ° C. or lower.
For example, when cyclized polyisoprene having an unsaturated bond reduction rate of 68% is used as the oxygen-absorbing resin (A1) and liquid paraffin is used as the softening agent (A2), the mass of the liquid paraffin is preferably oxygen-absorbing. The range is 15% or more of the total mass of the resin (A1) and liquid paraffin.
The blending ratio of the softening agent (A2) is preferably in the range of 15 to 80% by mass, more preferably 15 to 40% by mass with respect to the total of the oxygen-absorbing resin (A1) and the softening agent (A2). . When the mass ratio of the oxygen-absorbing resin (A1) and the softening agent (A2) is within the above range, the oxygen-absorbing property of the obtained oxygen-absorbing resin composition (A) tends to be good.

  Although the glass transition temperature of the oxygen absorptive resin composition (A) used by this invention is not specifically limited, It is preferable that it is -30-30 degreeC. When the glass transition temperature of the oxygen-absorbing resin composition (A) is in this range, the oxygen-absorbing resin composition (A) exhibits particularly excellent oxygen absorbability.

［前記一般式（II）中、ｎは２〜１８の整数を表す。前記一般式（III）中、Ａｒはアリーレン基を表す。］
ただし、ジアミン単位とジカルボン酸単位との合計は１００モル％を超えないものとする。ポリアミド樹脂（Ｂ）は、本発明の効果を損なわない範囲で、ジアミン単位及びジカルボン酸単位以外の構成単位を更に含んでいてもよい。 << Polyamide resin (B) >>
The oxygen-absorbing polyamide resin composition (C) of the present invention is obtained by melt-mixing the aforementioned oxygen-absorbing resin composition (A) and at least the polyamide resin (B).
The polyamide resin (B) is composed of a diamine unit containing at least 50 mol% or more of at least one aromatic diamine unit represented by the following general formula (I), and a linear aliphatic represented by the following general formula (II) It contains a dicarboxylic acid unit and / or a dicarboxylic acid unit containing 50 mol% or more in total of aromatic dicarboxylic acid units represented by the following general formula (III).

[In said general formula (II), n represents the integer of 2-18. In the general formula (III), Ar represents an arylene group. ]
However, the sum total of a diamine unit and a dicarboxylic acid unit shall not exceed 100 mol%. The polyamide resin (B) may further contain a constituent unit other than the diamine unit and the dicarboxylic acid unit as long as the effects of the present invention are not impaired.

In the polyamide resin (B), the content of diamine units is preferably 25 to 50 mol%, and more preferably 30 to 50 mol% from the viewpoint of oxygen absorption performance and properties of the polyamide resin (B). Similarly, in the polyamide resin (B), the content of dicarboxylic acid units is preferably 25 to 50 mol%, more preferably 30 to 50 mol%.
The ratio of the content of the diamine unit and the dicarboxylic acid unit in the polyamide resin (B) is preferably substantially the same from the viewpoint of the polymerization reaction, and the content of the dicarboxylic acid unit is ± of the content of the diamine unit. More preferably, it is within 2 mol%. When the content of the dicarboxylic acid unit is within a range of ± 2 mol% of the content of the diamine unit, the degree of polymerization of the polyamide resin (B) is likely to increase, so the degree of polymerization can be increased in a short time. Thermal deterioration of the resin (B) can be suppressed.

[Diamine unit]
The diamine unit in the polyamide resin (B) contains at least one aromatic diamine unit represented by the general formula (I) in a total of 50 mol% or more in the diamine unit.
The content of at least one aromatic diamine unit represented by the general formula (I) in the polyamide resin (B) is preferably 70 mol% or more, more preferably 80 mol% or more, and further preferably It is 90 mol% or more, and preferably 100 mol% or less.

  Examples of the compound that can constitute the aromatic diamine unit represented by the general formula (I) include orthoxylylenediamine, metaxylylenediamine, and paraxylylenediamine. These can be used alone or in combination of two or more.

  The diamine unit in the polyamide resin (B) facilitates the improvement of transparency and color tone and the moldability of a general-purpose thermoplastic resin in addition to imparting excellent gas barrier properties to the polyamide resin (B). From the viewpoint, the aromatic diamine unit represented by the general formula (I) is included. In particular, the oxygen absorption performance and the properties of the polyamide resin (B) can be improved.

The aromatic diamine unit represented by the general formula (I) is preferably a metaxylylenediamine unit.
Furthermore, the diamine unit in the polyamide resin (B) is metaxylylenediamine from the viewpoint of facilitating the moldability of a general-purpose thermoplastic resin in addition to exhibiting excellent gas barrier properties in the polyamide resin (B). It is preferable to contain 50 mol% or more of units. The content of the metaxylylenediamine unit in the diamine unit of the polyamide resin (B) is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, , Preferably it is 100 mol% or less.

  As a compound that can constitute a diamine unit other than the diamine unit represented by the general formula (I), an aromatic diamine such as paraphenylenediamine, 1,3-bisaminocyclohexane, 1,4-bisaminocyclohexane, 1, Alicyclic diamines such as 3-diaminocyclohexane and 1,4-diaminocyclohexane, linear aliphatic diamines having 2 to 18 carbon atoms, N-methylethylenediamine, 2-methyl-1,5-pentanediamine, 1- Examples include aliphatic diamines such as amino-3-aminomethyl-3,5,5-trimethylcyclohexane, polyether diamines having ether bonds represented by Huntsman's Jeffamine and Elastamine (both trade names) However, it is not limited to these. These can be used alone or in combination of two or more.

[Dicarboxylic acid unit]
The dicarboxylic acid unit in the polyamide resin (B) is a linear aliphatic dicarboxylic acid unit represented by the general formula (II) from the viewpoints of reactivity during polymerization and crystallinity and moldability of the polyamide resin (B). And / or the aromatic dicarboxylic acid unit represented by the general formula (III) is contained in a total of 50 mol% in the dicarboxylic acid unit.
Hereinafter, the linear aliphatic dicarboxylic acid unit represented by the general formula (II) is also referred to as a specific aliphatic dicarboxylic acid unit, and the aromatic dicarboxylic acid unit represented by the general formula (III) is referred to as a specific aromatic dicarboxylic acid. Also called a unit.
The content of the specific aliphatic dicarboxylic acid unit and the specific aromatic dicarboxylic acid unit in the dicarboxylic acid unit is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more. And preferably 100 mol% or less.
The content of the specific aliphatic dicarboxylic acid unit and the specific aromatic dicarboxylic acid unit is such that when the polyamide resin (B) includes only one of the specific aliphatic dicarboxylic acid unit and the specific aromatic dicarboxylic acid unit, The content of only one is expressed, and when both are included, the total amount of both is expressed.

The specific aliphatic dicarboxylic acid unit can impart flexibility necessary for a packaging material or a packaging container in addition to imparting an appropriate glass transition temperature and crystallinity to the polyamide resin (B).
In general formula (II), n represents the integer of 2-18. n is preferably 3 to 16, more preferably 4 to 12, and still more preferably 4 to 8.
The compounds that can constitute the specific aliphatic dicarboxylic acid unit include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,10-decanedicarboxylic acid, and 1,11-undecanedicarboxylic acid. 1,12-dodecanedicarboxylic acid and the like, but are not limited thereto. These can be used alone or in combination of two or more.

The kind of the specific aliphatic dicarboxylic acid unit is appropriately determined according to the use.
The specific aliphatic dicarboxylic acid unit in the polyamide resin (B), in addition to imparting excellent gas barrier properties to the polyamide resin (B), from the viewpoint of maintaining heat resistance after heat sterilization of the packaging material or packaging container, It is preferable that at least one selected from the group consisting of an adipic acid unit, a sebacic acid unit, and a 1,12-dodecanedicarboxylic acid unit is contained in a total of 50 mol% or more in the specific aliphatic dicarboxylic acid unit. The content is more preferably 70 mol% or more, still more preferably 80 mol% or more, particularly preferably 90 mol% or more, and preferably 100 mol% or less.

The specific aliphatic dicarboxylic acid unit in the polyamide resin (B) is a specific aliphatic dicarboxylic acid from the viewpoint of the gas barrier properties of the polyamide resin (B) and the thermal properties such as an appropriate glass transition temperature and melting point. It is preferable to contain 50 mol% or more in the unit.
The specific aliphatic dicarboxylic acid unit in the polyamide resin (B) is 50 moles of sebacic acid unit in the specific aliphatic dicarboxylic acid unit from the viewpoint of imparting appropriate gas barrier properties and moldability to the polyamide resin (B). % Or more is preferable.
When the polyamide resin (B) is used for applications requiring low water absorption, weather resistance, and heat resistance, the specific aliphatic dicarboxylic acid unit may contain 50 mol% or more of the 1,12-dodecanedicarboxylic acid unit. preferable.

The specific aromatic dicarboxylic acid unit is preferable in that it can facilitate the molding processability of the packaging material or the packaging container in addition to imparting further gas barrier properties to the polyamide resin (B).
In general formula (III), Ar represents an arylene group. The arylene group preferably has 6 to 30 carbon atoms, more preferably an arylene group having 6 to 15 carbon atoms. Examples of the arylene group include a phenylene group and a naphthylene group.
Examples of the compound that can constitute the specific aromatic dicarboxylic acid unit include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and the like, but are not limited thereto. These can be used alone or in combination of two or more.

The kind of the specific aromatic dicarboxylic acid unit is appropriately determined according to the use.
In the specific aromatic dicarboxylic acid unit, the specific aromatic dicarboxylic acid unit in the polyamide resin (B) is at least one selected from the group consisting of an isophthalic acid unit, a terephthalic acid unit, and a 2,6-naphthalenedicarboxylic acid unit. It is preferable to contain 50 mol% or more in total. The content is more preferably 70 mol% or more. More preferably, it is 80 mol% or more, Most preferably, it is 90 mol% or more, Preferably it is 100 mol% or less.
Among these, it is preferable to contain isophthalic acid and / or terephthalic acid in the specific aromatic dicarboxylic acid unit. The content ratio of the isophthalic acid unit to the terephthalic acid unit [(isophthalic acid unit / terephthalic acid unit); also referred to as “iso / tere ratio”] is not particularly limited and is appropriately determined depending on the application.
For example, from the viewpoint of reducing the polyamide resin (B) to an appropriate glass transition temperature and lowering the crystallinity of the polyamide resin (B), the iso / tere ratio is 100 mol in total of isophthalic acid units and terephthalic acid units. The molar ratio is preferably 0/100 to 100/0, more preferably 0/100 to 60/40, still more preferably 0/100 to 40/60, still more preferably 0/100. ~ 30/70.

In the dicarboxylic acid unit in the polyamide resin (B), the content ratio of the specific aliphatic dicarboxylic acid unit to the specific aromatic dicarboxylic acid unit [(specific aliphatic dicarboxylic acid unit / specific aromatic dicarboxylic acid unit); “F / A The ratio is also appropriately determined according to the application.
For example, when the purpose is to increase the glass transition temperature of the polyamide resin (B) to lower the crystallinity of the polyamide resin (B), the F / A ratio is determined by the specific aliphatic dicarboxylic acid unit and the specific aromatic dicarboxylic acid. When the total amount with the acid unit is 100 mol, the molar ratio is preferably 0/100 to 60/40, more preferably 0/100 to 40/60, still more preferably 0/100 to 30/70. It is.
In addition, when the purpose is to lower the glass transition temperature of the polyamide resin (B) to impart flexibility to the polyamide resin (B), the F / A ratio is determined based on the specific aliphatic dicarboxylic acid unit and the specific aromatic dicarboxylic acid. When the total with the unit is 100 mol, the molar ratio is preferably 40/60 to 100/0, more preferably 60/40 to 100/0, still more preferably 70/30 to 100/0. is there.

  Examples of the compound that can constitute a dicarboxylic acid unit other than the dicarboxylic acid unit represented by the general formula (II) or (III) include oxalic acid, malonic acid, fumaric acid, maleic acid, 1,3-benzenediacetic acid, 1 However, it is not limited to dicarboxylic acids such as 1,4-benzenediacetic acid.

［前記一般式（Ｐ）中、ｐは２〜１８の整数を表す。］ [Ω-aminocarboxylic acid unit]
In the present invention, when the polyamide resin (B) needs flexibility, the polyamide resin (B) is represented by the following general formula (P) in addition to the diamine unit and the dicarboxylic acid unit. -You may further contain an aminocarboxylic acid unit.

[In said general formula (P), p represents the integer of 2-18. ]

The content of the ω-aminocarboxylic acid unit is preferably 0.1 to 50 mol%, more preferably 3 to 40 mol%, still more preferably 5 to 5 mol% in all the structural units of the polyamide resin (B). 35 mol%. However, the total of the diamine unit, dicarboxylic acid unit, and ω-aminocarboxylic acid unit in the polyamide resin (B) does not exceed 100 mol%.
In General Formula (P), p represents an integer of 2 to 18, preferably 3 to 16, more preferably 4 to 14, and still more preferably 5 to 12.

  Examples of the compound that can constitute the ω-aminocarboxylic acid unit represented by the general formula (P) include ω-aminocarboxylic acid having 5 to 19 carbon atoms and lactam having 5 to 19 carbon atoms. Examples of the ω-aminocarboxylic acid having 5 to 19 carbon atoms include 6-aminohexanoic acid and 12-aminododecanoic acid, and examples of the lactam having 5 to 19 carbon atoms include ε-caprolactam and laurolactam. However, it is not limited to these. These can be used alone or in combination of two or more.

  The ω-aminocarboxylic acid unit preferably contains a total of 50 mol% or more of 6-aminohexanoic acid units and / or 12-aminododecanoic acid units in the ω-aminocarboxylic acid units. The content is more preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and preferably 100 mol% or less.

[Polymerization degree of polyamide resin (B)]
The degree of polymerization of the polyamide resin (B) can be determined from the relative viscosity of the polyamide resin (B). The preferred relative viscosity of the polyamide resin (B) is preferably 1.8 to 4.2, more preferably 1.9 to 4.0, from the viewpoint of the strength and appearance of the molded product and molding processability. More preferably, it is 2.0-3.8.
The relative viscosity here was measured in the same manner as the dropping time (t) measured at 25 ° C. with a Canon Fenceke viscometer by dissolving 0.2 g of polyamide resin (B) in 20 mL of 96% sulfuric acid. It is a ratio to the drop time (t ₀ ) of 96% sulfuric acid itself, and is represented by the following formula.
Relative viscosity = t / t ₀

[Terminal amino group concentration]
The terminal amino group concentration of the polyamide resin (B) is not particularly limited, but from the viewpoint of particularly improving the oxygen absorption rate of the oxygen-absorbing polyamide resin composition (C), it may be 50 μeq / g or less. preferable. The terminal amino group concentration is more preferably in the range of 5 to 50 μeq / g, further preferably 5 to 40 μeq / g, and particularly preferably 5 to 30 μeq / g.

<Method for producing polyamide resin (B)>
The polyamide resin (B) includes a diamine component that can constitute the diamine unit, a dicarboxylic acid component that can constitute the dicarboxylic acid unit, and an ω-aminocarboxylic acid component that can constitute the ω-aminocarboxylic acid unit if necessary. Can be produced by polycondensation. Moreover, the polymerization degree of a polyamide resin (B) is controllable by adjusting polycondensation conditions etc. A small amount of monoamine or monocarboxylic acid may be added as a molecular weight modifier during polycondensation. Further, in order to suppress the polycondensation reaction and obtain a desired degree of polymerization, the ratio (molar ratio) between the diamine component and the carboxylic acid component constituting the polyamide resin (B) may be adjusted by shifting from 1.

  Examples of the polycondensation method of the polyamide resin (B) include, but are not limited to, a reactive extrusion method, a pressurized salt method, an atmospheric pressure dropping method, and a pressure dropping method. Moreover, the one where reaction temperature is as low as possible can suppress the yellowing and gelatinization of a polyamide resin (B), and the polyamide resin (B) of the stable property is obtained.

[Normal pressure dropping method]
In the normal pressure dropping method, a diamine component is continuously dropped into a mixture obtained by heating and melting a dicarboxylic acid component under normal pressure, and a copolymerization component is polycondensed while removing condensed water. The polycondensation reaction is preferably performed while raising the temperature of the reaction system so that the reaction temperature does not fall below the melting point of the polyamide resin (B) to be produced.
Compared with the pressurized salt method, the atmospheric pressure dropping method does not use water for dissolving the salt, and thus the yield per batch tends to increase. In addition, since it is not necessary to vaporize and condense the raw material components, there is little decrease in the reaction rate, and the process time can be shortened.

[Pressure drop method]
In the pressure dropping method, first, a dicarboxylic acid component is charged into a reaction vessel, and each component is stirred, melted and mixed to prepare a mixture. Next, the diamine component is continuously added dropwise to the mixture while the inside of the reaction vessel is preferably pressurized to about 0.3 to 0.4 MPaG, and each component is polycondensed while removing condensed water. At this time, it is preferable to carry out the polycondensation reaction while raising the temperature of the reaction system so that the reaction temperature does not fall below the melting point of the produced polyamide resin (B). When the set molar ratio is reached, the addition of the diamine component is terminated, and while gradually raising the inside of the can to normal pressure, the temperature is raised to about the melting point of the polyamide resin (B) + 10 ° C. and maintained, and then −0.02 MPaG The pressure is gradually reduced until it is maintained at the same temperature, and the polycondensation is continued. When a certain stirring torque is reached, the inside of the reaction vessel is pressurized to about 0.3 MPaG with nitrogen to recover the polyamide resin (B).
The pressure drop method is useful when a volatile component is used as a monomer, as in the pressure salt method. By using the pressure drop method, the transpiration of the monomer component can be prevented and the polycondensation reaction can proceed smoothly, so that the polyamide resin (B) having excellent properties can be obtained. Furthermore, since the pressure drop method does not use water for dissolving the salt compared to the pressure salt method, the yield per batch is large, and the reaction time can be shortened as in the atmospheric pressure drop method. A polyamide resin (B) having a low yellowness can be obtained.

[Step of increasing the degree of polymerization of polyamide resin (B)]
The polyamide resin (B) produced by each of the above polycondensation methods can be used as it is, but may be subjected to a step for further increasing the degree of polymerization. Further, examples of the process for increasing the degree of polymerization include reactive extrusion in an extruder, solid phase polymerization, and the like.
As the heating device used in the solid phase polymerization, a continuous heating drying device, a tumble dryer, a conical dryer, a rotary drum type heating device called a rotary dryer, etc., and a rotary blade inside a nauta mixer are used. A conical heating device provided is preferred. A heating apparatus is not limited to these, A well-known method and apparatus can be used.
In particular, when solid-phase polymerization of polyamide resin (B) is performed, among the above-mentioned heating devices, the rotary drum type heating device can seal the inside of the system and polycondensate in a state where oxygen that causes coloring is removed. It is preferably used because it is easy to proceed.

[Phosphorus atom-containing compound, alkali metal compound]
In the polycondensation of the polyamide resin (B), it is preferable to add a phosphorus atom-containing compound to the polyamide resin (B) from the viewpoint of promoting the amidation reaction.
Examples of the phosphorus atom-containing compound include phosphinic acid compounds such as dimethylphosphinic acid and phenylmethylphosphinic acid; hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, lithium hypophosphite, magnesium hypophosphite, Diphosphite compounds such as calcium hypophosphite and ethyl hypophosphite; phosphonic acid, sodium phosphonate, potassium phosphonate, lithium phosphonate, magnesium phosphonate, calcium phosphonate, phenylphosphonic acid, ethylphosphonic acid, phenylphosphone Phosphonic acid compounds such as sodium phosphate, potassium phenylphosphonate, lithium phenylphosphonate, diethyl phenylphosphonate, sodium ethylphosphonate, potassium ethylphosphonate; phosphonous acid, sodium phosphonite, lithium phosphonite, Phosphonous compounds such as potassium sulfonate, magnesium phosphonite, calcium phosphonite, phenylphosphonite, sodium phenylphosphonite, potassium phenylphosphonite, lithium phenylphosphonite, ethyl phenylphosphonite; Phosphorous acid, sodium hydrogen phosphite, sodium phosphite, lithium phosphite, potassium phosphite, magnesium phosphite, calcium phosphite, triethyl phosphite, triphenyl phosphite, pyrophosphorous acid, etc. A phosphoric acid compound etc. are mentioned.
Among these, hypophosphorous acid metal salts such as sodium hypophosphite, potassium hypophosphite, and lithium hypophosphite are particularly preferable because they have a high effect of promoting amidation reaction and are excellent in anti-coloring effect. In particular, sodium hypophosphite is preferred. In addition, the phosphorus atom containing compound which can be used by this invention is not limited to these compounds.
The addition amount of the phosphorus atom-containing compound is preferably 0.1 to 1,000 ppm, more preferably 1 to 600 ppm, still more preferably 5 to 400 ppm in terms of phosphorus atom concentration in the polyamide resin (B). is there. If it is 0.1 ppm or more, the polyamide resin (B) is difficult to be colored during polymerization, and the transparency becomes high. If it is 1,000 ppm or less, the polyamide resin (B) is difficult to be gelled, and it is possible to reduce the mixing of fish eyes considered to be caused by the phosphorus atom-containing compound into the molded product, and the appearance of the molded product is improved. . Furthermore, considering the influence on the oxygen absorption rate of the oxygen-absorbing polyamide resin composition (C), 500 ppm or less is desirable.

Moreover, it is preferable to add an alkali metal compound in combination with the phosphorus atom-containing compound in the polycondensation system of the polyamide resin (B). In order to prevent the polyamide resin (B) from being colored during the polycondensation, it is necessary to have a sufficient amount of the phosphorus atom-containing compound, but in some cases, the polyamide resin (B) may be gelled. In order to adjust the amidation reaction rate, it is preferable to coexist an alkali metal compound.
As the alkali metal compound, alkali metal hydroxide, alkali metal acetate, alkali metal carbonate, alkali metal alkoxide and the like are preferable. Specific examples of the alkali metal compound that can be used in the present invention include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, lithium acetate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate. Sodium methoxide, sodium ethoxide, sodium propoxide, sodium butoxide, potassium methoxide, lithium methoxide, sodium carbonate and the like, but can be used without being limited to these compounds.
In addition, the ratio (molar ratio) between the phosphorus atom-containing compound and the alkali metal compound is phosphorus atom-containing compound / alkali metal compound = 1.0 / 0.05 to 1 from the viewpoint of controlling the polymerization rate and reducing the yellowness. The range of 0.0 / 1.5 is preferable, more preferably 1.0 / 0.1 to 1.0 / 1.2, still more preferably 1.0 / 0.2 to 1.0 / 1. .1.

  The mixing ratio of the oxygen-absorbing resin composition (A) and the polyamide resin (B) constituting the oxygen-absorbing polyamide resin composition (C) is not particularly limited, but the oxygen-absorbing resin composition (A) / polyamide is not particularly limited. It is preferable that resin (B) is 1 / 99-50 / 50 by mass ratio, More preferably, it is 10 / 90-30 / 70. Within this range, the oxygen absorption performance and gas barrier performance are well balanced and good oxygen absorption performance and gas barrier performance are easily exhibited.

<< Additives >>
The oxygen-absorbing polyamide resin composition (C) of the present invention may further contain additives as necessary in addition to the oxygen-absorbing resin composition (A) and the polyamide resin (B). One type of additive may be used, or a combination of two or more types may be used. Although the content of the additive in the oxygen-absorbing polyamide resin composition (C) depends on the type of the additive, it is preferably 10% by mass or less, and more preferably 5% by mass or less.

[Whitening inhibitor, lubricant]
In the present invention, after white water treatment and after a long period of time, whitening suppression, bleeding out suppression, and further, as a lubricant, a fatty acid metal salt, a diamide compound and / or a diester compound are used as an oxygen-absorbing polyamide resin composition (C ). Fatty acid metal salts, diamide compounds and / or diester compounds are effective in suppressing whitening due to oligomer precipitation. Fatty acid metal salts, diamide compounds and diester compounds may be used alone or in combination.

As the fatty acid metal salt that can be used in the present invention, from the viewpoint of whitening suppression effect after sterilization treatment by hot water treatment and uniform dispersibility in the oxygen-absorbing polyamide resin composition (C), carbon number of 18 to 50, A fatty acid metal salt having 18 to 34 carbon atoms is preferred.
Fatty acids may have side chains and / or double bonds, but stearic acid (18 carbon atoms), eicoic acid (20 carbon atoms), behenic acid (22 carbon atoms), montanic acid (28 carbon atoms), tria Straight chain saturated fatty acids such as contanic acid (30 carbon atoms) are preferred. The metal that forms a salt with the fatty acid is not particularly limited, and examples thereof include alkali metals such as sodium, potassium and lithium, alkaline earth metals such as calcium, barium, magnesium and strontium, and aluminum and zinc. Among these, sodium, potassium, lithium, calcium, aluminum, or zinc is particularly preferable.
Specific examples of the fatty acid metal salt include sodium stearate, calcium stearate, sodium montanate, calcium montanate and the like. Among these, calcium stearate and calcium montanate are preferable from the viewpoint of whitening suppression effect. The said fatty acid metal salt may contain only 1 type and may contain it in combination of 2 or more type.
Fatty acid metal salts are excellent in handling properties, and among these, stearic acid metal salts are preferable because they are inexpensive and have an effect as a lubricant and can stabilize the molding process. In particular, calcium stearate is preferable. Furthermore, the shape of the fatty acid metal salt is not particularly limited. However, when the fatty acid metal salt is dry-mixed in the oxygen-absorbing polyamide resin composition (C), the fatty acid metal salt should be a powder and have a smaller particle size. It is easy to uniformly disperse the fatty acid metal salt in the composition (C). Therefore, the particle size of the fatty acid metal salt is preferably 0.2 mm or less.

In the present invention, the amount of fatty acid metal salt, diamide compound and / or diester compound added is preferably 0.005 to 0.5 mass%, more preferably 0 in the oxygen-absorbing polyamide resin composition (C). It is 0.01-0.3 mass%, More preferably, it is 0.02-0.1 mass%.
By adding 0.005% by mass or more of such an additive to the oxygen-absorbing polyamide resin composition (C) and using it together with a crystallization nucleating agent, a synergistic effect of preventing whitening can be expected. Moreover, when the addition amount is 0.5% by mass or less with respect to the oxygen-absorbing polyamide resin composition (C), it is possible to keep the haze value of the molded product obtained by molding the composition (C) low. It becomes.

[Oxidation reaction accelerator]
In order to further enhance the oxygen absorption performance of the oxygen-absorbing polyamide resin composition (C), a conventionally known oxidation reaction accelerator may be added as long as the effects of the present invention are not impaired. The oxidation reaction accelerator can promote the oxygen absorption performance of the oxygen-absorbing resin composition (A), thereby enhancing the oxygen-absorbing performance of the oxygen-absorbing polyamide resin composition (C).
Examples of the oxidation reaction accelerator include Group VIII metals such as iron, cobalt and nickel, Group I metals such as copper and silver, Group IV metals such as tin, titanium and zirconium, Group V of vanadium, Examples include low-valent inorganic or organic acid salts of Group VI metals such as chromium and Group VII metals such as manganese, or complex salts of the above transition metals.
However, the oxygen-absorbing polyamide resin composition (C) of the present invention can exhibit sufficient oxygen absorption performance without adding an oxidation reaction accelerator. Therefore, from the viewpoint of suppressing the generation of odor from the oxygen-absorbing polyamide resin composition (C) and preventing deterioration of color tone, strength, etc. due to oxidative deterioration of the composition (C), the transition metal as described above. It is preferable to reduce the addition amount of the oxygen reaction accelerator represented by the compound as much as possible. Specifically, the addition amount of the oxygen reaction accelerator to the oxygen-absorbing polyamide resin composition (C) is preferably 800 ppm or less, more preferably 100 ppm or less as a metal atom concentration, and substantially More preferably, it is 0 ppm.

[Oxygen absorber]
In order to further enhance the oxygen absorption performance of the oxygen-absorbing polyamide resin composition (C), a conventionally known oxygen absorbent may be added within a range not impairing the effects of the present invention. In addition to the oxygen-absorbing performance of the oxygen-absorbing resin composition (A), the oxygen-absorbing agent imparts oxygen-absorbing performance to the oxygen-absorbing polyamide resin composition (C), thereby absorbing oxygen in the composition (C). Performance can be increased.
Examples of the oxidation reaction accelerator include oxidizable organic compounds typified by compounds having a carbon-carbon double bond in the molecule, such as vitamin C, vitamin E, butadiene, and isoprene.
In the present invention, the amount of the oxygen absorbent added to the oxygen-absorbing polyamide resin composition (C) is preferably 0.01 to 5% by mass, more preferably based on the total mass of the composition (C). Is 0.1 to 4% by mass, more preferably 0.5 to 3% by mass.

Furthermore, as a prescription for preventing gelation of the more effective oxygen-absorbing polyamide resin composition (C), reducing fish eyes, and preventing kogation, carboxylates are sodium acetate having a high metal salt concentration per gram. Is preferably used. The fish eye refers to a state in which massive foreign matters exist in the sheet or film when the oxygen-absorbing polyamide resin composition (C) is formed into a sheet or film.
When sodium acetate is used, it may be dry-mixed with the polyamide resin (B) and molded, but from the viewpoints of handling properties, reduction of acetic acid odor, etc., a masterbatch comprising the polyamide resin (B) and sodium acetate is polyamide. It is preferable to dry mix with the resin (B) for molding. Since it is easy to disperse | distribute sodium acetate used for a masterbatch uniformly to a polyamide resin (B), 0.2 mm or less is preferable and the particle size is more preferable.

[Antioxidant]
In the present invention, the composition (C) may contain an antioxidant from the viewpoint of controlling the oxygen-absorbing performance of the oxygen-absorbing polyamide resin composition (C) and suppressing deterioration of mechanical properties.
Examples of the antioxidant include copper-based antioxidants, hindered phenol-based antioxidants, hindered amine-based antioxidants, phosphorus-based antioxidants, and thio-based antioxidants. Antioxidants and phosphorus antioxidants are preferred.

  The content of the antioxidant can be used without particular limitation as long as it does not impair the various performances of the oxygen-absorbing polyamide resin composition (C). From the viewpoint of controlling the oxygen-absorbing performance of the oxygen-absorbing polyamide resin composition (C) and suppressing deterioration of mechanical properties, the content of the antioxidant in the composition (C) is preferably 0.001 to 3 mass. %, More preferably 0.01 to 1% by mass.

[Other additives]
The oxygen-absorbing polyamide resin composition (C) has a matting agent, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, a plasticizer, a flame retardant, an antistatic agent, and coloring depending on the required use and performance. Additives such as inhibitors and crystallization nucleating agents may be added. These additives can be added as necessary within a range not impairing the effects of the present invention.

The method for preparing the oxygen-absorbing polyamide resin composition (C) of the present invention is not particularly limited, and the oxygen-absorbing resin (A1) and the polyamide resin (B), the softener (A2) used as necessary, and the like. These resins and various additives may be mixed by any method.
The order of mixing is not particularly limited, and each component may be mixed at once, or some components may be mixed in advance and the remaining components may be mixed with this.
The kneading apparatus is not particularly limited, and specifically, it can be carried out using various kneading apparatuses such as a single screw extruder or a multi-screw extruder such as a twin screw, a Banbury mixer, a roll, a kneader. The mixing temperature is in a range of 230 to 260 ° C. in which each resin is melted and can be melt-mixed well and each component is not thermally deteriorated.

<< Configuration of multilayer molded product >>
The multilayer molded article of the present invention comprises at least one layer (X) containing the oxygen-absorbing polyamide resin composition (C) of the present invention (hereinafter also referred to as “oxygen-absorbing barrier layer”). And a layer (Y) mainly composed of the resin (D).
The types of the layer (X) and the layer (Y) are not particularly limited except that the layer (X) contains the oxygen-absorbing polyamide resin composition (C) and the layer (Y) contains a resin. Moreover, the layer structure in the multilayer molded body of the present invention, that is, the position structure of the layer (X) and the layer (Y) is not particularly limited, and the number of layers (X) and layers (Y) is not particularly limited.
For example, an X / Y configuration or a Y / X configuration including one layer (X) and one layer (Y) may be used, and one layer (X) and two layers (Y) may be used. A three-layer structure of Y / X / Y may be used. Alternatively, a five-layer configuration of Y1 / Y2 / X / Y2 / Y1 composed of one layer (X) and two types and four layers (Y) of the layer (Y1) and the layer (Y2) may be used. Furthermore, an arbitrary layer such as an adhesive layer (AD) may be included as required. For example, a five-layer structure such as Y / AD / X / AD / Y, Y1 / AD / Y2 / X / Y2 / AD / A seven-layer configuration such as Y3, Y1 / AD / Y2 / X / Y2 / AD / Y1, and the like can be given.

  In the multilayer molded body, the position of the oxygen absorption barrier layer is preferably close to the inner layer. When the oxygen-absorbing barrier layer is present at a position close to the inner layer, when the multilayer molded body is used as a container containing moisture or packaging of the container, the oxygen absorption rate is increased by the moisture in the contents of the container that triggers oxygen absorption. And oxygen absorption begins early. Furthermore, by providing a high barrier resin layer outside the oxygen absorption barrier layer, oxygen from the outside of the container can be blocked and the oxygen absorption barrier layer can efficiently absorb oxygen remaining in the container.

1. Layer (X) containing oxygen-absorbing polyamide resin composition (C) (oxygen-absorbing barrier layer)
In this invention, an oxygen absorption barrier layer can exhibit oxygen absorption performance and oxygen barrier performance by containing the oxygen-absorbing polyamide resin composition (C) described above. The oxygen-absorbing polyamide resin composition (C) contained in the oxygen-absorbing barrier layer may be one type or a combination of two or more types.
In the present invention, the oxygen-absorbing barrier layer contains the oxygen-absorbing polyamide resin composition (C) as a main resin composition component.
As described above, a resin other than the oxygen-absorbing polyamide resin composition (C) may be added to the oxygen-absorbing barrier layer, and as the added resin, the oxygen-absorbing barrier layer is within a range that does not impair the object of the present invention. Various conventionally known resins may be used depending on the performance desired to be imparted. For example, from the viewpoint of imparting impact resistance, pinhole resistance and flexibility, polyolefins such as polyethylene and polypropylene and various modified products thereof, polyolefin-based elastomers, polyamide-based elastomers, styrene-butadiene copolymer resins and hydrogens thereof Examples of additive-treated products, various thermoplastic elastomers typified by polyester elastomers, and various polyamides such as nylon 6, nylon 66, nylon 12, etc. Examples thereof include carbon-carbon unsaturated double bond-containing resins. The additive resin may be one kind or a combination of two or more kinds. The ratio of the additive resin in the total resin of the oxygen absorption barrier layer is preferably 5% by mass or less.
In addition to the oxygen-absorbing polyamide resin composition (C), the oxygen-absorbing barrier layer includes the additives described above according to desired performance and the like in addition to the additives added to the oxygen-absorbing polyamide resin composition (C). However, the content of the oxygen-absorbing polyamide resin composition (C) in the oxygen-absorbing barrier layer is 90% by mass to 100% by mass from the viewpoints of moldability, oxygen-absorbing performance, and oxygen-barrier performance. %, And more preferably 95% by mass to 100% by mass.
The thickness of the oxygen-absorbing barrier layer is preferably 2 to 100 μm, more preferably from the viewpoint of securing various physical properties such as flexibility required for the multilayer molded article while enhancing oxygen absorption performance and oxygen barrier performance. Is 5 to 90 μm, more preferably 10 to 80 μm.

2. Layer mainly composed of resin (D) (Y)
The layer (Y) in this invention is a layer which has resin (D) as a main component.
Here, “main component” means that the layer (Y) contains 70% by mass or more of the resin (D). Content of resin (D) in a layer (Y) becomes like this. Preferably it is 80 mass% or more, More preferably, it is 90-100 mass%. The layer (Y) may contain the additive in addition to the resin (D) depending on the desired performance.
The multilayer molded body of the present invention may have a plurality of layers (Y), and the configuration of the plurality of layers (Y) may be the same as or different from each other.
The thickness of the layer (Y) can be appropriately determined according to the application. From the viewpoint of ensuring various physical properties such as flexibility required for the multilayer molded body, the thickness of the layer (Y) is preferably 5 to 1,000 μm, more preferably 50 to 900 μm, and still more preferably. Is 100 to 800 μm.

Resin (D)
In the present invention, the resin (D) can be any resin and is not particularly limited. As the resin (D), for example, a thermoplastic resin can be used, and specific examples thereof include polyolefin, polyester, polyamide, ethylene-vinyl alcohol copolymer, and plant-derived resin. In the present invention, the resin (D) preferably contains at least one selected from the group consisting of these resins.
The “polyamide” shown as an example of the resin (D) is different from the “polyamide resin (B)” used in the present invention.
Among these, polyolefins, polyesters, polyamides and ethylene-vinyl alcohol copolymers are preferable, and oxygen barrier properties such as polyesters, polyamides and ethylene-vinyl alcohol copolymers are effective in order to effectively exhibit the oxygen absorption effect. Higher resin is more preferable.

[Polyolefin]
Specific examples of polyolefin include olefins such as polyethylene (low density polyethylene, medium density polyethylene, high density polyethylene, linear (linear) low density polyethylene), polypropylene, polybutene-1, and poly-4-methylpentene-1. Homopolymer; Copolymer of ethylene and α-olefin such as ethylene-propylene random copolymer, ethylene-propylene block copolymer, ethylene-propylene-polybutene-1 copolymer, ethylene-cyclic olefin copolymer Ethylene-α, β-unsaturated carboxylic acid copolymer such as ethylene- (meth) acrylic acid copolymer, ethylene-α, β-unsaturated carboxylic acid such as ethylene- (meth) acrylic acid ethyl copolymer Ester copolymer, ionic cross-linked product of ethylene-α, β-unsaturated carboxylic acid copolymer, ethylene - Other ethylene copolymers such as vinyl acetate copolymer; may be mentioned graft-modified polyolefin grafted modifying these polyolefins with an acid anhydride such as maleic anhydride.

[Other resins]
The layer (Y) may contain various conventionally known resins as long as the object of the present invention is not impaired.
For example, from the viewpoint of imparting impact resistance, pinhole resistance, flexibility and adhesiveness to a multilayer molded body, as various known resins, polyolefins such as polyethylene and polypropylene, and various modified products thereof, polyolefins Examples include elastomers, polyamide-based elastomers, styrene-butadiene copolymer resins and hydrogenated products thereof, various thermoplastic elastomers represented by polyester-based elastomers, and various polyamides such as nylon 6, nylon 66, and nylon 12. From the viewpoint of further imparting oxygen absorption performance to the multilayer molded body, examples of various known resins include carbon-carbon unsaturated double bond-containing resins such as polybutadiene and modified polybutadiene.

[Any layer]
In addition to the layer (X) and the layer (Y), the multilayer molded body of the present invention may contain any layer depending on the desired performance. Examples of such an arbitrary layer include an adhesive layer, a metal foil, and a metal vapor deposition layer.

[Adhesive layer]
In the multilayer molded body of the present invention, when practical interlayer adhesive strength cannot be obtained between two adjacent layers, it is preferable to provide an adhesive layer between the two layers.
The adhesive layer preferably contains a thermoplastic resin having adhesiveness. As the thermoplastic resin having adhesiveness, for example, an acid modification in which a polyolefin resin such as polyethylene or polypropylene is modified with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, etc. Examples include polyolefin resins. As the adhesive layer, it is preferable to use a modified resin of the same type as the resin (D) used as the layer (Y) from the viewpoint of adhesiveness.
The thickness of the adhesive layer is preferably 2 to 100 μm, more preferably 5 to 90 μm, and still more preferably 10 from the viewpoint of ensuring the moldability of the multilayer molded body while exhibiting practical adhesive strength. ˜80 μm.

[Method for producing multilayer molded article]
The method for producing the multilayer molded body of the present invention is not particularly limited, and the multilayer molded body can be produced by any method. For example, the multilayer molded body is preferably formed by a thermoforming method, particularly, a T-die method. For example, using a multi-layer extruder composed of a plurality of extruders, feed blocks, and T dies, the oxygen-absorbing polyamide resin composition (C) and the other resin (D) materials such as polyolefin are respectively introduced into the hopper. Then, it is melted in an extruder and extruded from a T die to a cooling roll to form a multilayer molded body.
The extruder used here may be a single-screw extruder or a multi-screw extruder. The screw used for extrusion of the oxygen-absorbing polyamide resin composition (C) is not particularly limited, but a rapid compression full flight screw and a double flight screw are preferable.
In addition to the single manifold method using a feed block, a multi-manifold method having a plurality of manifolds inside the T die may be used.
Examples of incidental equipment for the extruder include a take-up machine equipped with a cooling roll, a sheet edge cutting device, a vent vacuum pump, and a cooling machine.

The multilayer molded body of the present invention can be further molded into a container or the like. For example, a multilayer formed body is once formed into a sheet, and then the sheet is further softened by heating, and the sheet is brought into close contact with the mold by vacuum or compressed air or a thermoforming method using both vacuum and compressed air to form a container. There is a method in which the container is obtained by molding and trimming. Here, the sheet surface temperature during thermoforming is preferably in the range of 130 to 200 ° C and more preferably in the range of 150 to 180 ° C from the viewpoint of formability. The multilayer molded body manufacturing apparatus and the container molding method are not limited to these, and any method can be applied.
In addition, this container uses a multilayer molded body made of the same type of resin as the flange part of the container as the container lid, and after being filled with the object to be stored by hot plate welding, high frequency welding, etc., it is thermally welded and sealed. It is possible to Moreover, it is preferable to use a protrusion, an easily peelable material, or the like so that the lid material does not open at the time of the heat sterilization treatment and / or falls, and the lid material is easily peeled off when the container is opened.

The multilayer molded body of the present invention may be produced by a method such as a coextrusion method or a lamination method.
[Co-extrusion method]
In the coextrusion method, the material constituting the layer (X) and the material constituting the layer (Y) are respectively charged into an extruder and coextruded to obtain a multilayer molded body. For the coextrusion, any method such as coextrusion by an inflation method or coextrusion by a T-die method can be used.
The multilayer molded body obtained by the coextrusion method may be further stretched by uniaxial stretching or biaxial stretching to form a multilayer molded body in which the layers (X) and (Y) are co-stretched.
Examples of the stretching method include continuous biaxial stretching by the tenter method or simultaneous biaxial stretching by the tenter method, or simultaneous biaxial stretching by the inflation method. A batch-type biaxial stretching apparatus may be used. The stretching ratio in stretching after co-extrusion can be appropriately determined according to the use of the multilayer molded body, but biaxial stretching is 1.1 to 15 times in the MD direction and 1.1 to 15 times in the TD direction. Is preferred.

[Lamination method]
In the laminating method, a film constituting the layer (X) and a film constituting the layer (Y) are each produced by an extrusion method or the like, and then these films are laminated to obtain a multilayer molded body.
The type of the laminating method is not particularly limited, and any method such as a hot melt lamination method, a wet lamination method, a dry lamination method, a solventless dry lamination method, an extrusion lamination method, or a thermal lamination method can be used.
When laminating films, if necessary, pretreatment such as corona treatment and ozone treatment can be applied to the film or the like. Also, for example, anchor coating agents such as isocyanate (urethane), polyethyleneimine, polybutadiene, and organic titanium; laminates such as polyurethane, polyacryl, polyester, epoxy, polyvinyl acetate, and cellulose Known anchor coat agents such as adhesives, adhesives and the like can be used.

Moreover, after performing appropriate surface treatment on the surface of a film, a printing layer can also be provided on the surface which surface-treated as needed.
When providing a printing layer, general printing equipment used for printing on conventional polymer films, such as a gravure printing machine, a flexographic printing machine, and an offset printing machine, can be applied. Moreover, the ink used for the conventional printing layer formation to a polymer film is applicable also to the ink for printing layer formation. For example, an ink containing a pigment such as azo or phthalocyanine, a resin such as rosin, polyamide resin, or polyurethane, a solvent such as methanol, ethyl acetate, or methyl ethyl ketone may be used.

<< Film packaging container >>
The multilayer molded body of the present invention can be used, for example, to constitute a film packaging container. The film packaging container using the multilayer molded body of the present invention as a whole or a part of the packaging container absorbs oxygen in the container in addition to oxygen slightly entering from the outside of the container, and changes the contents of the stored article due to oxygen. Can be prevented.
The shape of the film packaging container is not particularly limited, and can be selected within an appropriate range depending on the article to be stored or stored. For example, the multilayer molded body of the present invention is composed of a three-side sealed flat bag, a standing pouch, a gusset packaging bag, a pillow packaging bag, a main chamber and a sub chamber, and an easy peeling wall provided between the main chamber and the sub chamber. It can be a chamber pouch, a thermoformed container, a shrink film packaging, or the like. Moreover, when it has flange parts, such as a thermoforming container, you may give the special process which provides an easy peeling function to the flange part. Moreover, a deoxidation function can be provided to a packaging container by using the multilayer molded body of this invention as members, such as a cover material of a container and a top seal.
The capacity of the film packaging container is not particularly limited, and can be selected within an appropriate range depending on the article to be stored or stored.
It does not specifically limit about the manufacturing method of the film packaging container of this invention, It can manufacture by arbitrary methods.

The packaging container formed of the multilayer molded article of the present invention is excellent in oxygen absorption performance and oxygen barrier performance, and is excellent in flavor retention of contents, and thus is suitable for packaging various articles.
Examples of the preservative of the packaging container comprising the multilayer molded body of the present invention include beverages such as milk, dairy products, juice, coffee, teas, alcoholic beverages; liquid seasonings such as sauces, soy sauce, dressings, soups, stews, Curry, cooked food for infants, cooked food for nursing care, etc .; pasty food such as jam, mayonnaise, ketchup, jelly; marine products such as tuna and fish shellfish; dairy products such as cheese and butter; meat, salami, Processed livestock products such as sausages and ham; vegetables such as carrots and potatoes; eggs; noodles; processed rice products such as cooked rice, cooked rice and rice bran before cooking; powdered seasonings, powdered coffee, for infants Powdered milk, powdered diet food, dried foods such as dried vegetables and rice crackers; chemicals such as pesticides and insecticides; pharmaceuticals; cosmetics; pet foods; miscellaneous goods such as shampoos, rinses and detergents; Articles of the people can be mentioned. Among these, heat-sterilization treatment such as boil treatment, retort treatment, etc., jelly using pulp, fruit juice, coffee, etc., sheep cooked rice, cooked cooked rice, processed rice products, infant cooked food, nursing cooked food, curry, soup , Stew, jam, mayonnaise, ketchup, pet food, and processed fishery products.

  In addition, before and after the filling of these objects to be preserved, the packaging container and / or the object to be preserved composed of a multilayer molded body can be sterilized in a form suitable for the objects to be preserved. As sterilization methods, hot water treatment (boil treatment) at 100 ° C. or lower, pressurized hot water treatment (retort treatment) at 100 ° C. or higher, ultra high temperature heat treatment at 130 ° C. or higher, ultraviolet light, microwave, Examples include electromagnetic wave sterilization using electromagnetic waves such as gamma rays, gas treatment using a gas such as ethylene oxide, and chemical sterilization using chemicals such as hydrogen peroxide and hypochlorous acid.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

[Method for producing oxygen-absorbing resin (A1)]
Polyisoprene (cis-1,4 units 73%, trans-1,4 units 22%, 3, 3%) was cut into a 10 mm square pressure reactor equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube. 4-unit 5%, weight average molecular weight 243,100) 100 parts by mass were charged together with 374 parts by mass of cyclohexane. After purging the inside of the reactor with nitrogen, the mixture was heated to 75 ° C. and the polyisoprene was completely dissolved in cyclohexane with stirring, and then p-toluenesulfonic acid (in toluene, so that the water content was 150 ppm or less, The cyclization reaction was performed while adding 0.90 parts by mass as a 15% toluene solution and controlling the temperature not to exceed 80 ° C. After reacting for 7 hours, 25% sodium carbonate aqueous solution containing 0.59 parts by mass of sodium carbonate was added to stop the reaction. After removing water by azeotropic reflux dehydration at 80 ° C., the catalyst residue in the system was removed with a glass fiber filter having a pore size of 2 μm. Cyclohexane was distilled off from the obtained solution, and further toluene was removed by vacuum drying to obtain a solid conjugated diene polymer cyclized product.
The conjugated diene polymer cyclized product [oxygen-absorbing resin (A1)] had a weight average molecular weight of 189,100, an unsaturated bond reduction rate of 62.6%, and a glass transition temperature of 56 ° C. The obtained solid conjugated diene polymer cyclized product was cylinder 1: 140 using a single screw kneading extruder [40φ, L / D = 25, die diameter 3 mm × 1 hole, manufactured by Ikekai Co., Ltd.]. C., cylinder 2: 150.degree. C., cylinder 3: 160.degree. C., cylinder 4: 170.degree. C., die temperature 170.degree. The weight average molecular weight, unsaturated bond reduction rate, and glass transition temperature of the conjugated diene polymer cyclized product were measured by the following methods.

(1) Weight average molecular weight (Mw)
The weight average molecular weight (Mw) was calculated | required as a polystyrene conversion molecular weight using the gel permeation chromatography. Tetrahydrofuran was used as an elution solvent.

(2) Unsaturated bond reduction rate The unsaturated bond reduction rate of the conjugated diene polymer cyclized product was determined by proton NMR analysis of the conjugated diene polymer and the conjugated diene polymer cyclized product. In proton NMR analysis, (i) M.M. A. Golub and J.M. Heller, Can. J. et al. Chem. 41, 937 (1963). And (ii) Y. Tanaka and H.M. Sato, J .; Polym. Sci: Poly. Chem. Ed. 17, 3027 (1979). The method described in the literature was referred to.
In the conjugated diene monomer unit portion in the conjugated diene polymer, the total proton peak area before the cyclization reaction is SBT, the peak area of the proton directly bonded to the double bond is SBU, and the total proton after the cyclization reaction Assuming that the peak area is SAT and the peak area of the proton directly bonded to the double bond is SAU, the peak area ratio (SB) of the proton directly bonded to the double bond before the cyclization reaction is expressed by the formula: SB = SBU / SBT The peak area ratio (SA) of protons directly bonded to the double bond after the cyclization reaction is represented by the formula: SA = SAU / SAT. Therefore, the unsaturated bond reduction rate is obtained by the formula: unsaturated bond reduction rate (%) = 100 × (SB−SA) / SB.

(3) Glass transition temperature (Tg) of conjugated diene polymer cyclized product
The glass transition temperature was measured using a differential scanning calorimeter [Seiko Instruments Co., Ltd., "EXSTAR 6000 DSC"] in a nitrogen stream at a heating rate of 10 ° C / min.

[Polyamide resin (B)]
In the present invention, polyamide resins B1 to B5 shown in the following Production Examples 1 to 5 were used as the polyamide resin (B). The relative viscosity, terminal amino group concentration, glass transition temperature and melting point of these polyamide resins (B) were measured by the following methods.

Production Example 1 (Production of polyamide resin B1)
Weighed precisely in a pressure-resistant reaction vessel with an internal volume of 50 L equipped with a stirrer, partial condenser, full condenser, pressure regulator, thermometer, dripping tank and pump, aspirator, nitrogen inlet pipe, bottom exhaust valve, and strand die. Adipic acid (AdA) [Asahi Kasei Chemicals Co., Ltd.] 13000 g (88.95 mol), high-purity isophthalic acid (PIA) [Aji International Chemical Co., Ltd.] 943.3 g (5.68 mol), Sodium hypophosphite 2.40 g (0.023 mol) and sodium acetate 1.25 g (0.015 mol) were added and sufficiently purged with nitrogen, then the reaction vessel was sealed and the vessel was kept at 0.4 MPa. The temperature was raised to 170 ° C. with stirring. After reaching 170 ° C., dropwise addition of 12811.8 g (94.07 mol) of metaxylylenediamine (MXDA) [Mitsubishi Gas Chemical Co., Ltd.] stored in the dropping tank to the molten raw material in the reaction vessel, While removing the condensed water produced outside the system while maintaining the inside of the vessel at 0.4 MPa, the temperature in the reaction vessel was continuously raised to 260 ° C. After completion of the dropwise addition of metaxylylenediamine, the inside of the reaction vessel was gradually returned to normal pressure, and then the inside of the reaction vessel was reduced to 80 kPa using an aspirator to remove condensed water. After observing the stirring torque of the stirrer during decompression, stop stirring when the specified torque is reached, pressurize the inside of the reaction tank with nitrogen, open the bottom drain valve, extract the polymer from the strand die and form a strand Cooled and pelletized with a pelletizer. Next, this pellet was charged into a stainless steel drum-type heating device and rotated at 5 rpm. The atmosphere in the reaction system was raised from room temperature to 140 ° C. under a small amount of nitrogen stream. When the temperature in the reaction system reached 140 ° C., the pressure was reduced to 1 torr (133.32 Pa) or less, and drying was performed at 140 ° C. for 8 hours. After completion of drying, the decompression was terminated, the system temperature was lowered under a nitrogen stream, and the pellets were taken out when the temperature reached 60 ° C. to obtain an MXDA / AdA / PIA polymer (polyamide resin B1).
In addition, the preparation composition ratio of each monomer was metaxylylenediamine: adipic acid: high purity isophthalic acid = 49.9: 47.1: 3.0 (mol%).

Production Example 2 (Production of polyamide resin B2)
Weighed precisely in a pressure-resistant reaction vessel with an internal volume of 50 L equipped with a stirrer, partial condenser, full condenser, pressure regulator, thermometer, dripping tank and pump, aspirator, nitrogen inlet pipe, bottom exhaust valve, and strand die. Adipic acid [Asahi Kasei Chemicals Co., Ltd.] 13000 g (88.95 mol), high-purity isophthalic acid [A. G. International Chemical Co., Ltd.] 943.3 g (5.68 mol), sodium hypophosphite 2 .40 g (0.023 mol) and sodium acetate 1.25 g (0.015 mol) were added and sufficiently purged with nitrogen, then the reaction vessel was sealed, and the temperature was raised to 170 ° C. with stirring while keeping the vessel at 0.4 MPa. Warm up. After reaching 170 ° C., dripping 12811.8 g (94.07 mol) of metaxylylenediamine (manufactured by Mitsubishi Gas Chemical Co., Inc.) stored in the dropping tank into the molten raw material in the reaction vessel was started, The reaction vessel was continuously heated to 260 ° C. while removing condensed water produced while maintaining at 0.4 MPa. After completion of the dropwise addition of metaxylylenediamine, the inside of the reaction vessel was gradually returned to normal pressure, and then the inside of the reaction vessel was reduced to 80 kPa using an aspirator to remove condensed water. After observing the stirring torque of the stirrer during decompression, stop stirring when the specified torque is reached, pressurize the inside of the reaction tank with nitrogen, open the bottom drain valve, extract the polymer from the strand die and form a strand Cooled and pelletized with a pelletizer. Next, this pellet was charged into a stainless steel drum-type heating device and rotated at 5 rpm. The atmosphere in the reaction system was raised from room temperature to 140 ° C. under a small amount of nitrogen stream. When the reaction system temperature reached 140 ° C., the pressure was reduced to 1 torr (133.32 Pa) or less, and the system temperature was further increased to 180 ° C. over 110 minutes. From the time when the system temperature reached 180 ° C., the solid state polymerization reaction was continued at the same temperature for 180 minutes. After completion of the reaction, the decompression was terminated, the system temperature was lowered under a nitrogen stream, and the pellet was taken out when the temperature reached 60 ° C., thereby obtaining an MXDA / AdA / PIA polymer (polyamide resin B2).
In addition, the preparation composition ratio of each monomer was metaxylylenediamine: adipic acid: high purity isophthalic acid = 49.9: 47.1: 3.0 (mol%).

Production Example 3 (Production of polyamide resin B3)
With respect to the polyamide resin B2 (100 parts by mass) obtained in Production Example 2, calcium stearate [manufactured by NOF Corporation] and a spreader [NOION LT manufactured by NOF Corporation] so that the calcium stearate [manufactured by NOF Corporation] is 400 ppm. -221 "(polyoxyethylene sorbitan monolaurate)] was added and stirred and mixed in a rotary drum to obtain polyamide resin B3 added with 400 ppm of calcium stearate as a lubricant.
In addition, the preparation composition ratio of each monomer was metaxylylenediamine: adipic acid: high purity isophthalic acid = 49.9: 47.1: 3.0 (mol%).

Production Example 4 (Production of polyamide resin B4)
A polyamide resin B4 was obtained in the same manner as in Production Example 2 except that the solid phase polymerization time after reaching 180 ° C. was 240 minutes during the solid phase polymerization.
In addition, the preparation composition ratio of each monomer was metaxylylenediamine: adipic acid: high purity isophthalic acid = 49.9: 47.1: 3.0 (mol%).

Production Example 5 (Production of polyamide resin B5)
A polyamide resin B5 was obtained in the same manner as in Production Example 2, except that the copolymerization rate of high-purity isophthalic acid was changed to 6 mol% and the copolymerization rate of adipic acid was changed to 44.1 mol%.
In addition, the preparation composition ratio of each monomer was metaxylylenediamine: adipic acid: high purity isophthalic acid = 49.9: 44.1: 6.0 (mol%).

(1) Relative viscosity of polyamide resin (B) 0.2 g of a pellet-like sample of polyamide resin (B) was weighed accurately and dissolved in 20 mL of 96% sulfuric acid at 20 to 30 ° C. After completely dissolving, 5 mL of the solution was quickly taken into a Cannon Fenceke viscometer, allowed to stand in a constant temperature bath at 25 ° C. for 10 minutes, and then the falling time (t) was measured. Further, the dropping time (t ₀ ) of 96% sulfuric acid itself was measured in the same manner. The relative viscosity was calculated from t and t _{0 according} to the following formula.
Relative viscosity = t / t ₀

(2) Terminal amino group concentration of polyamide resin (B) [NH ₂ ]
The polyamide resin (B) is precisely weighed and dissolved in a phenol / ethanol = 4/1 volume solution by stirring at 20 to 30 ° C., and after complete dissolution, the inner wall of the container is washed away with 5 mL of methanol while stirring. The terminal amino group concentration [NH ₂ ] was determined by neutralization titration with an / L hydrochloric acid aqueous solution.

(3) Glass transition temperature and melting point of polyamide resin (B) Using a differential scanning calorimeter [manufactured by Shimadzu Corporation, trade name: DSC-60], DSC measurement under a nitrogen stream at a heating rate of 10 ° C./min. (Differential scanning calorimetry) was performed to determine the glass transition temperature (Tg) and the melting point (Tm).

  Table 1 shows the measurement results of the charged monomer composition, the lubricant addition amount, the relative viscosity, the terminal amino group concentration, the glass transition temperature, and the melting point of the polyamide resin used for the polyamide resins B1 to B5 used.

[Example 1]
16.5 parts by mass of pellets of cyclized conjugated diene polymer obtained in Production Example, 3.5 parts by mass of liquid paraffin [manufactured by Kaneda Co., Ltd., “High Coal K-350”], and polyamide resin B1 (80.0 masses) Part) using a twin-screw kneading extruder [43φ, L / D = 33.5, “ZE40A” manufactured by Berstroff Co., Ltd.], cylinder 1: 180 ° C., cylinder 2: 240 ° C., cylinder 3: 240 ° C., cylinder 4: Kneading was performed under kneading conditions of 240 ° C., a die temperature of 290 ° C., and a rotational speed of 150 rpm, and pelletized to obtain pellets of the oxygen-absorbing polyamide resin composition of Example 1. The oxygen-absorbing polyamide resin composition of Example 1 had a configuration in which an oxygen-absorbing resin composition comprising a conjugated diene polymer cyclized product and liquid paraffin was dispersed in a polyamide resin. Moreover, it was 0 degreeC when the glass transition temperature of the oxygen absorptive resin composition (A) contained in an oxygen absorptive polyamide resin composition was measured. The composition of each component and the glass transition temperature of the oxygen-absorbing resin composition (A) in the oxygen-absorbing polyamide resin composition of Example 1 are shown in Table 2. The glass transition temperature of the oxygen-absorbing resin composition was measured at 10 ° C./min in a nitrogen stream using a differential scanning calorimeter (“EXSTAR 6000 DSC” manufactured by Seiko Instruments Inc.). .

Next, using a multilayer extruder equipped with three extruders, a feed block, and a T die, the oxygen-absorbing polyamide resin composition of Example 1 was extruded from the first extruder at 250 ° C. for the second. From the machine, polypropylene [manufactured by Nippon Polypro Co., Ltd., trade name: Novatec, grade: FY6] is 230 ° C., and the adhesive resin [manufactured by Mitsui Chemicals, trade name: Admer, grade: QB515] was extruded at 220 ° C. onto 30 ° C. cooling rolls and wound up. The multilayer sheet (multilayer molded body) obtained here has a three-kind five-layer structure in the order of the outer layer, polypropylene layer / adhesive resin layer / oxygen-absorbing polyamide resin composition layer / adhesive resin layer / polypropylene layer. The thickness of each layer was 355/12/66/12/355 (μm).
Next, thermoforming was performed when the sheet surface temperature reached 170 ° C. using a compressed air vacuum forming machine (manufactured by Asano Laboratory Co., Ltd.) equipped with a plug assist, and the opening was 79 mm square × bottom 63 mm × depth. A multilayer container having a thickness of 25 mm, a surface area of 110 cm ² and a volume of 100 mL was produced. This multilayer container was subjected to an oxygen barrier property evaluation after retorting. The results of the oxygen barrier property evaluation after the retort treatment are shown in Table 2.

[Examples 2 to 5]
The oxygen-absorbing polyamide resin composition pellets of Examples 2 to 5 were prepared in the same manner as in Example 1 except that the material to be mixed was changed to polyamide resins B2 to B5 instead of the polyamide resin B1 of Example 1. Thus, a multi-layer container was prepared and subjected to an oxygen barrier property evaluation after the retort treatment. In the oxygen-absorbing polyamide resin compositions of Examples 2 to 5, the blending amount of each component, the glass transition temperature of the oxygen-absorbing resin composition, and the results of the oxygen barrier property evaluation after retorting of the multilayer container are shown in Table 2. Indicated.

[Comparative Example 1]
A multilayer container was prepared in the same manner as in Example 1 except that the polyamide resin B1 was used for forming a multilayer sheet as it was instead of the pellets of the oxygen-absorbing polyamide resin composition of Example 1, and a retort-treated container was prepared. It used for oxygen barrier property evaluation. The results of the oxygen barrier property evaluation after the retort treatment of this multilayer container are shown in Table 2.

[Comparative Example 2]
Example except that ethylene-vinyl alcohol copolymer [manufactured by Kuraray Co., Ltd., “EVAL L171B”] was used as it was for forming a multilayer sheet instead of the pellet of the oxygen-absorbing polyamide resin composition of Example 1. In the same manner as in Example 1, a multi-layer container was prepared and subjected to evaluation of oxygen barrier properties after retorting. The results of the oxygen barrier property evaluation after the retort treatment of this multilayer container are shown in Table 2.

[Comparative Example 3]
The oxygen absorption of Comparative Example 3 was performed in the same manner as in Example 1 except that the material to be mixed was an ethylene-vinyl alcohol copolymer [“Eval L171B” manufactured by Kuraray Co., Ltd.] instead of the polyamide resin B1. The pellet of the functional resin composition was obtained, a multilayer container was produced, and it used for oxygen barrier property evaluation after a retort process. Table 2 shows the blending amount of each component, the glass transition temperature of the oxygen-absorbing resin composition, and the oxygen barrier property evaluation results after the retorting of the multilayer container in the oxygen-absorbing resin composition of Comparative Example 3.

In Examples 1 to 5 and Comparative Examples 1 to 3, the oxygen barrier property evaluation after the retort treatment of the multilayer container was performed according to the following method. That is, the multilayer container used as a sample was retort-treated at 121 ° C. and 0.3 MPa for 30 minutes using a steam heating retort treatment device [Alp Co., Ltd., “Retort High Pressure Steam Sterilizer RK-3030”]. For the multilayer container after the retort treatment, the oxygen permeability is measured for 300 days in an atmosphere of 23 ° C. and a relative humidity of 60% using an oxygen permeability measuring device [manufactured by MOCON, “OX-TRAN2 / 61”]. The amount of oxygen that entered the multilayer container (unit: mL) was determined from the measured value. Table 2 shows the oxygen transmission rates after 1 day, 2 days, 3 days, 30 days, 150 days, and 300 days after placing the multilayer container as a sample in an atmosphere of 23 ° C. and 60% relative humidity. Table 2 also shows the cumulative oxygen permeation amount for all 300 days.
The smaller the amount of oxygen that enters, the better the oxygen barrier properties after retorting.

  As can be seen from the above results, the multilayer containers of Examples 1 to 5 obtained by using the oxygen-absorbing polyamide resin composition of the present invention can be used even after being left in the air for 300 days after retorting. It was excellent in oxygen barrier property so that oxygen could not enter into it. On the other hand, when the cups of Comparative Examples 1 to 3 were left in the air for 300 days after the retort treatment, oxygen entered the inside. Therefore, the oxygen-absorbing polyamide resin composition of the present invention has an excellent oxygen barrier property and a container in which the oxygen concentration in the container can be kept low even when left in the air after retorting. It can be said that packaging can be given.

  A packaging container comprising a multilayer molded article comprising the oxygen-absorbing polyamide resin composition and the oxygen-absorbing polyamide resin composition of the present invention can be suitably used as a packaging material or the like.

Claims (14)

An oxygen-absorbing polyamide resin composition obtained by melt-mixing an oxygen-absorbing resin composition (A) containing an oxygen-absorbing resin (A1) composed of a conjugated diene polymer cyclized product and a polyamide resin (B). ,
The polyamide resin (B) is a linear fat represented by the following general formula (II) and a diamine unit containing at least one aromatic diamine unit represented by the following general formula (I) in a total amount of 50 mol% or more: Oxygen-absorbing polyamide resin composition containing an aromatic dicarboxylic acid unit and / or a dicarboxylic acid unit containing 50 mol% or more of the aromatic dicarboxylic acid unit represented by the following general formula (III).

[In said general formula (II), n represents the integer of 2-18. In the general formula (III), Ar represents an arylene group. ]   The mixing ratio of the oxygen-absorbing resin composition (A) and the polyamide resin (B) is mass ratio, and the oxygen-absorbing resin composition (A) / polyamide resin (B) = 1/99 to 50/50. The oxygen-absorbing polyamide resin composition according to claim 1.   The conjugated diene polymer cyclized product is obtained by cyclizing the conjugated diene polymer, and a proton NMR analysis is performed to determine the unsaturated bond reduction rate of the conjugated diene polymer cyclized product relative to the number of unsaturated bonds in the conjugated diene polymer. The oxygen-absorbing polyamide resin composition according to claim 1 or 2, wherein the value determined in this manner is 10% or more.   The oxygen-absorbing polyamide resin composition according to any one of claims 1 to 3, wherein the oxygen-absorbing resin composition (A) further contains a softening agent (A2).   The oxygen-absorbing polyamide resin composition according to claim 4, wherein the softening agent (A2) is liquid paraffin or polybutene.   The oxygen-absorbing polyamide resin composition according to any one of claims 1 to 5, wherein a glass transition temperature of the oxygen-absorbing resin composition (A) is -30 to 30 ° C.   The oxygen-absorbing polyamide resin composition according to any one of claims 1 to 6, wherein the terminal amino group concentration of the polyamide resin (B) is 50 µeq / g or less.   The oxygen-absorbing polyamide resin composition according to any one of claims 1 to 7, wherein the amount of the fatty acid metal salt in the oxygen-absorbing polyamide resin composition is 0.5% by mass or less.   The oxygen-absorbing polyamide resin composition according to any one of claims 1 to 8, wherein the polyamide resin (B) has a relative viscosity of 1.8 or more and 4.2 or less.   The oxygen-absorbing polyamide resin composition according to any one of claims 1 to 9, wherein the diamine unit contains 50 mol% or more of a metaxylylenediamine unit.   The linear aliphatic dicarboxylic acid unit contains at least one selected from the group consisting of an adipic acid unit, a sebacic acid unit, and a 1,12-dodecanedicarboxylic acid unit in total of 50 mol% or more. The oxygen-absorbing polyamide resin composition according to any one of the above.   The aromatic dicarboxylic acid unit contains at least one selected from the group consisting of an isophthalic acid unit, a terephthalic acid unit, and a 2,6-naphthalenedicarboxylic acid unit in a total of 50 mol% or more. An oxygen-absorbing polyamide resin composition according to claim 1.   It has at least 2 layers of the layer (X) containing the oxygen absorptive polyamide resin composition in any one of Claims 1-12, and the layer (Y) which has at least 1 type of resin (D) as a main component. , Multilayer molded body.   The multilayer molded body according to claim 13, wherein the resin (D) is at least one selected from the group consisting of polyolefins, polyesters, polyamides, and ethylene-vinyl alcohol copolymers.