WO2013002078A1

WO2013002078A1 - Laminate and paper container

Info

Publication number: WO2013002078A1
Application number: PCT/JP2012/065652
Authority: WO
Inventors: 大滝　良二; 尚史小田; 健太郎石井; 翔太荒川
Original assignee: 三菱瓦斯化学株式会社
Priority date: 2011-06-27
Filing date: 2012-06-19
Publication date: 2013-01-03
Also published as: TW201311449A; JP5954326B2; JPWO2013002078A1; AR086758A1

Abstract

A laminate including a paper base layer and a layer containing a polyamide resin, and a paper container formed from the laminate. The polyamide resin contains 25 to 50 mol% of diamine units that comprise 50 mol% or more of a specific diamine unit, 25 to 50 mol% of dicarboxylic acid units that comprise 50 mol% or more of a specific dicarboxylic acid unit, and 0.1 to 50 mol% of a specific constituent unit.

Description

Laminate and paper container

The present invention relates to a laminated material having oxygen barrier performance and oxygen absorption performance, and a paper container formed by boxing it.

Conventionally, a glass bottle, a metal container, a paper container formed by laminating a resin and a paper substrate, and the like are widely used as packaging materials for liquid articles. In particular, a paper container formed by laminating a resin and a paper base material is light and safe, and its usage is greatly increased. However, unlike a glass bottle or a metal container, a paper container has a property that oxygen can permeate from the outside, and there is a problem in the storage stability of the contents filled and sealed. As a means for solving this problem, a method of laminating a gas barrier material such as an aluminum foil, an inorganic oxide vapor deposition film, or a gas barrier resin as a constituent material is performed.
However, with paper containers laminated with aluminum foil, it is extremely difficult to separate and collect the laminated resin, aluminum foil, and paper substrate in resource recycling after use, and ash-like residues of aluminum foil are discarded when incinerated. There were problems such as making it difficult to dispose of materials. In addition, in a paper container laminated with an inorganic oxide vapor-deposited film, the inorganic oxide is a glassy and inflexible thin film, and is a thin film that lacks flexibility. There has been a problem that the gas barrier property is greatly lowered due to the occurrence of cracks or the like when the material is acted or folded during box making. The paper container laminated with a gas barrier resin has the characteristics that the above problems hardly occur, but its gas barrier performance is not perfect and its performance may deteriorate due to changes in temperature and humidity. Although it was possible to extend the storage period, deterioration of the contents due to oxidation was unavoidable and was not satisfactory.

In recent years, a method of laminating a layer having oxygen absorption performance in a paper container in which a gas barrier resin or the like is laminated has been disclosed in order to solve the above-described problems. For example, a paper container has been proposed in which an oxygen-absorbing resin layer in which an oxygen scavenger (oxygen absorber) based on metal powder is dispersed in polyolefin or adhesive polyolefin is laminated with a paper base (for example, Patent Document 1). To 2). In addition, a paper container has been proposed in which an oxygen scavenging resin layer bonded with a polyolefin segment having a carbon-carbon unsaturated bond in the molecule is laminated with a paper base (see, for example, Patent Document 3).
Patent Document 4 discloses a technique for expressing oxygen absorption performance by coexisting a cobalt compound with polymetaxylylene adipamide, which is described in Patent Document 3 as an oxygen-absorbing resin layer. By adopting such a layer structure, a paper container having oxygen absorption performance can be manufactured.

JP 2005-035570 A JP 2007-246120 A JP 2001-080014 A Japanese National Patent Publication No. 02-500846

The paper containers disclosed in Patent Documents 1 and 2 have a performance (oxygen barrier property) that blocks the permeation of oxygen from the outside to the inside of the paper container, and the remaining oxygen and contents in the head space in the paper container Although it also has the ability to absorb dissolved oxygen dissolved in it (oxygen absorption performance), it is excellent in the effect of suppressing the oxidative deterioration of the contents, but it is possible to provide a separate barrier layer in addition to the oxygen absorbing layer Since it is necessary, the material used more than before increases, resulting in poor economic efficiency. Further, since metal powder is used as an oxygen absorbent, there is a problem that depending on the contents, the metal odor shifts to the contents and impairs the flavor.
The paper container shown in Patent Document 3 can be configured with the same number of layers as a conventional paper container by applying a gas barrier resin as an oxygen-absorbing resin layer, but the oxidation of carbon-carbon unsaturated bonds proceeds. Low molecular weight organic substances such as aldehydes and ketones are generated, and the low molecular weight organic substances permeate the resin laminated inside the oxygen-absorbing resin layer and enter the head space, or in some cases dissolve in the contents There was a problem of impairing the flavor of the contents.
Although the oxygen-absorbing resin composition shown in Patent Document 4 hardly generates aldehydes and ketones that cause problems in Patent Document 3, it adopts a mechanism for absorbing oxygen by oxidative decomposition of polymetaxylylene adipamide. Therefore, the generation of low molecular weight substances occurs as well. Therefore, when a paper container in which the oxygen-absorbing resin composition of Patent Document 4 is applied as an oxygen-absorbing layer is produced, there is a possibility that a low molecular weight substance generated by oxidative decomposition of polymetaxylylene adipamide is mixed into the contents. In addition, there is a problem that the strength of the oxygen absorbing layer is lowered as oxygen absorption proceeds. A decrease in the strength of the oxygen absorbing layer not only causes a decrease in the strength of the paper container, but also has a problem of deteriorating the opening of the spout. That is, in paper containers with a mechanism that opens the spout by applying external stress, which is often used in paper containers having a top part of the top of the bell shape, oxygen is reduced in strength when the spout is opened. A phenomenon occurs in which the absorbing layer is broken and peeled off, and no longer peels off at a desired peeled surface. When such a phenomenon occurs, not only the appearance of the opened spout is deteriorated, but also the oxygen-absorbing layer that has deteriorated by oxidation comes into contact with the contents when pouring the contents. Is a problem.

The problem to be solved by the present invention is a paper container that can suppress the oxidative deterioration of the contents, and does not impair the flavor of the contents, and does not deteriorate the strength of the oxygen absorbing layer even during long-term storage It is providing the laminated body for manufacturing a paper container.

The present invention provides the following laminated material and paper container.
<1> a paper base material layer;
A laminated material comprising a layer containing a polyamide resin,
The polyamide resin is
An aromatic diamine unit represented by the following general formula (I-1), an alicyclic diamine unit represented by the following general formula (I-2), and a straight chain represented by the following general formula (I-3) 25 to 50 mol% of diamine units containing a total of 50 mol% or more of at least one diamine unit selected from the group consisting of aliphatic diamine units;
A dicarboxylic acid unit containing a total of 50 mol% or more of a linear aliphatic dicarboxylic acid unit represented by the following general formula (II-1) and / or an aromatic dicarboxylic acid unit represented by the following general formula (II-2) 25 to 50 mol%,
A laminated material containing 0.1 to 50 mol% of a structural unit represented by the following general formula (III).

[In the general formula (I-3), m represents an integer of 2 to 18. In the general formula (II-1), n represents an integer of 2 to 18. In the general formula (II-2), Ar represents an arylene group. In the general formula (III), R represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. ]
<2> A paper container formed by boxing the above laminated material.

The laminated material of the present invention exhibits oxygen barrier performance, can exhibit oxygen absorption performance without containing a transition metal, and extremely decreases the strength of the oxygen absorption barrier layer as oxygen absorption progresses. small. Therefore, the paper container of the present invention formed by boxing the laminated material is excellent in suppressing the oxidative deterioration of the contents, and hardly generates substances that cause a strange odor or a change in flavor. Also excellent. Furthermore, there is almost no deterioration of openability due to a decrease in strength of the oxygen absorption barrier layer.

<< Laminate >>
The laminated material of the present invention includes at least a paper base layer and a layer containing a polyamide resin (hereinafter also referred to as “oxygen absorption barrier layer”). The laminated material may further include an arbitrary layer such as a fusion layer or an adhesive layer as necessary.

1. Paper base material layer In the present invention, since the paper base material layer is a basic material constituting the container, it preferably has formability, bending resistance, rigidity, waist, strength, etc. Various paper base materials such as bleached or unbleached paper base, or pure white roll paper, kraft paper, paperboard, processed paper, etc. can be used.
The paper base layer preferably has a basis weight in the range of about 80 to 600 g / m ² and more preferably has a basis weight in the range of 100 to 450 g / m ² . In the present invention, on the paper base material layer, for example, a desired print pattern such as a character, a figure, a pattern, a symbol, or the like may be arbitrarily formed by a normal printing method.

2. Layer containing polyamide resin (oxygen absorption barrier layer)
In the present invention, the oxygen absorption barrier layer can exhibit oxygen absorption performance and oxygen barrier performance by containing a specific polyamide resin (hereinafter also referred to as “polyamide resin (A)”) described later. The polyamide resin (A) contained in the oxygen absorption barrier layer may be one kind or a combination of two or more kinds.
In this invention, an oxygen absorption barrier layer contains a polyamide resin (A) as a main resin component. A resin other than the polyamide resin (A) may be added to the oxygen absorption barrier layer, but the ratio of the polyamide resin (A) in the total resin of the oxygen absorption barrier layer is preferably more than 95% by mass. The resin contained in the oxygen absorption barrier layer may be only the polyamide resin (A), and the ratio of the polyamide resin (A) in the total resin of the oxygen absorption barrier layer is preferably 100% by mass or less.
As described above, a resin other than the polyamide resin (A) may be added to the oxygen-absorbing barrier layer, and as the added resin, performance that is desired to be imparted to the oxygen-absorbing barrier layer as long as the object of the present invention is not impaired. Depending on the above, various conventionally known resins may be used. For example, from the viewpoint of imparting impact resistance, pinhole resistance, and flexibility, polyolefins such as polyethylene and polypropylene, various modified products thereof, polyolefin elastomers, polyamide elastomers, styrene-butadiene copolymer resins and hydrogens thereof. Additives processed, various thermoplastic elastomers typified by polyester elastomers, various polyamides such as nylon 6, 66, 12 and nylon 12, etc. From the viewpoint of further imparting oxygen absorption performance, polybutadiene and modified polybutadiene And 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 polyamide resin (A), the oxygen-absorbing barrier layer may contain an additive to be described later (hereinafter also referred to as “additive (B)”) depending on the desired performance and the like. The content of the polyamide resin (A) in the oxygen absorption barrier layer is preferably 90% by mass to 100% by mass, and 95% by mass to 100% by mass from the viewpoints of moldability, oxygen absorption performance, and oxygen barrier performance. It is more preferable that
The thickness of the oxygen absorption barrier layer is preferably 2 to 100 μm, more preferably 5 to 5 μm from the viewpoint of ensuring workability when a laminated material is boxed while improving oxygen absorption performance and oxygen barrier performance. It is 90 μm, more preferably 10 to 80 μm.

2-1. Polyamide resin (A)
<Configuration of polyamide resin (A)>
In the present invention, the polyamide resin (A) includes an aromatic diamine unit represented by the following general formula (I-1), an alicyclic diamine unit represented by the following general formula (I-2), and the following general formula: 25 to 50 mol% of diamine units containing a total of 50 mol% or more of at least one diamine unit selected from the group consisting of linear aliphatic diamine units represented by (I-3), and the following general formula (II-1) 25 to 50 mol% of dicarboxylic acid units containing a total of 50 mol% or more of linear aliphatic dicarboxylic acid units represented by formula (II-2) and aromatic dicarboxylic acid units represented by the following general formula (II-2): Tertiary hydrogen-containing carboxylic acid unit (preferably a structural unit represented by the following general formula (III)) 0.1 to 50 mol%.

[In the general formula (I-3), m represents an integer of 2 to 18. In the general formula (II-1), n represents an integer of 2 to 18. In the general formula (II-2), Ar represents an arylene group. In the general formula (III), R represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. ]
However, the total of the diamine unit, the dicarboxylic acid unit, and the tertiary hydrogen-containing carboxylic acid unit shall not exceed 100 mol%. The polyamide resin (A) may further contain structural units other than those described above as long as the effects of the present invention are not impaired.

In the polyamide resin (A), the content of the tertiary hydrogen-containing carboxylic acid unit is 0.1 to 50 mol%. If the content of the tertiary hydrogen-containing carboxylic acid unit is less than 0.1 mol%, sufficient oxygen absorption performance is not exhibited. On the other hand, when the content of the tertiary hydrogen-containing carboxylic acid unit exceeds 50 mol%, the tertiary hydrogen content is too high, and the physical properties such as gas barrier properties and mechanical properties of the polyamide resin (A) are deteriorated. When the secondary hydrogen-containing carboxylic acid is an amino acid, the peptide bond is continuous, so that the heat resistance is not sufficient, and a cyclic product composed of a dimer of amino acids is formed, thereby inhibiting polymerization. The content of the tertiary hydrogen-containing carboxylic acid unit is preferably 0.2 mol% or more, more preferably 1 mol% or more, and preferably from the viewpoint of the oxygen absorption performance and the properties of the polyamide resin (A). It is 40 mol% or less, More preferably, it is 30 mol% or less.

In the polyamide resin (A), the diamine unit content is 25 to 50 mol%, and preferably 30 to 50 mol% from the viewpoint of oxygen absorption performance and polymer properties. Similarly, in the polyamide resin (A), the content of dicarboxylic acid units is 25 to 50 mol%, preferably 30 to 50 mol%.
The proportion of the content of the diamine unit and the dicarboxylic acid unit is preferably substantially the same from the viewpoint of the polymerization reaction, and the content of the dicarboxylic acid unit is ± 2 mol% of the content of the diamine unit. More preferred. If the content of the dicarboxylic acid unit exceeds the range of ± 2 mol% of the content of the diamine unit, the degree of polymerization of the polyamide resin (A) becomes difficult to increase, so it takes a lot of time to increase the degree of polymerization, Deterioration is likely to occur.

[Diamine unit]
The diamine unit in the polyamide resin (A) is an aromatic diamine unit represented by the general formula (I-1), an alicyclic diamine unit represented by the general formula (I-2), and the general formula. A total of 50 mol% or more of diamine units selected from the group consisting of linear aliphatic diamine units represented by (I-3) is contained in the diamine units, and the content is preferably 70 mol% Above, more preferably 80 mol% or more, still more preferably 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-1) include orthoxylylenediamine, metaxylylenediamine, and paraxylylenediamine. These can be used alone or in combination of two or more.

Examples of the compound capable of constituting the alicyclic diamine unit represented by the general formula (I-2) include bis (1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, and the like. Aminomethyl) cyclohexanes. These can be used alone or in combination of two or more.
Bis (aminomethyl) cyclohexanes have structural isomers, but by increasing the cis-isomer ratio, the crystallinity is high and good moldability can be obtained. On the other hand, if the cis-isomer ratio is lowered, a transparent material with low crystallinity can be obtained. Therefore, when it is desired to increase the crystallinity, the cis-isomer content ratio in the bis (aminomethyl) cyclohexane is preferably 70 mol% or more, more preferably 80 mol% or more, and still more preferably 90 mol% or more. . On the other hand, when it is desired to lower the crystallinity, the cis body content ratio in the bis (aminomethyl) cyclohexanes is preferably 50 mol% or less, more preferably 40 mol% or less, still more preferably 30 mol% or less. .

In the general formula (I-3), m represents an integer of 2 to 18, preferably 3 to 16, more preferably 4 to 14, and still more preferably 6 to 12.
Examples of the compound that can constitute the linear aliphatic diamine unit represented by the general formula (I-3) include ethylenediamine, 1,3-propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and heptamethylenediamine. And aliphatic diamines such as octamethylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, and dodecamethylene diamine, but are not limited thereto. Among these, hexamethylenediamine is preferable. These can be used alone or in combination of two or more.

As a diamine unit in the polyamide resin (A), in addition to imparting excellent gas barrier properties to the polyamide resin (A), the transparency and color tone are improved, and the moldability of a general-purpose thermoplastic resin is facilitated. From the viewpoint, it preferably contains an aromatic diamine unit represented by the general formula (I-1) and / or an alicyclic diamine unit represented by the general formula (I-2). From the standpoint of imparting appropriate crystallinity to (A), it is preferable to include a linear aliphatic diamine unit represented by the general formula (I-3). In particular, from the viewpoint of oxygen absorption performance and properties of the polyamide resin (A), it is preferable that the aromatic diamine unit represented by the general formula (I-1) is included.

The diamine unit in the polyamide resin (A) is a metaxylylenediamine unit 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 (A). The content is preferably 50 mol% or more, and the content 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.

Examples of the compound that can constitute a diamine unit other than the diamine unit represented by any one of the general formulas (I-1) to (I-3) include aromatic diamines such as paraphenylenediamine, and 1,3-diaminocyclohexane. Fats such as 1,4-diaminocyclohexane, alicyclic diamines, N-methylethylenediamine, 2-methyl-1,5-pentanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, etc. Examples include, but are not limited to, group diamines, polyether diamines having ether bonds represented by Huntsman's Jeffamine and elastamine (both are trade names), and the like. These can be used alone or in combination of two or more.

[Dicarboxylic acid unit]
The dicarboxylic acid unit in the polyamide resin (A) is a linear aliphatic group represented by the general formula (II-1) from the viewpoints of reactivity during polymerization and crystallinity and moldability of the polyamide resin (A). The dicarboxylic acid unit and / or the aromatic dicarboxylic acid unit represented by the general formula (II-2) is contained in the dicarboxylic acid unit in a total of 50 mol% or more, and the content is preferably 70 mol% or more, more Preferably it is 80 mol% or more, More preferably, it is 90 mol% or more, Preferably it is 100 mol% or less.

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

The type of the linear aliphatic dicarboxylic acid unit represented by the general formula (II-1) is appropriately determined according to the application. The linear aliphatic dicarboxylic acid unit in the polyamide resin (A) gives excellent gas barrier properties to the polyamide resin (A), and from the viewpoint of maintaining heat resistance after heat sterilization of the packaging material and 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 linear 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 linear aliphatic dicarboxylic acid unit in the polyamide resin (A) is a linear aliphatic unit from the viewpoint of gas barrier properties of the polyamide resin (A) and thermal properties such as an appropriate glass transition temperature and melting point. It is preferable to contain 50 mol% or more in the dicarboxylic acid unit. In addition, the linear aliphatic dicarboxylic acid unit in the polyamide resin (A) is converted from the sebacic acid unit to the linear aliphatic dicarboxylic acid unit from the viewpoint of imparting appropriate gas barrier properties and molding processability to the polyamide resin (A). When the polyamide resin (A) is used for applications requiring low water absorption, weather resistance, and heat resistance, the 1,12-dodecanedicarboxylic acid unit is a linear aliphatic group. It is preferable to contain 50 mol% or more in the dicarboxylic acid unit.

The aromatic dicarboxylic acid unit represented by the general formula (II-2) facilitates the molding processability of packaging materials and packaging containers in addition to imparting further gas barrier properties to the polyamide resin (A). It is preferable at the point which can do.
In the general formula (II-2), Ar represents an arylene group. The arylene group is preferably an arylene group having 6 to 30 carbon atoms, more preferably 6 to 15 carbon atoms, and examples thereof include a phenylene group and a naphthylene group.
Examples of the compound that can constitute the aromatic dicarboxylic acid unit represented by the general formula (II-2) include terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, but are not limited thereto. is not. These can be used alone or in combination of two or more.

The kind of the aromatic dicarboxylic acid unit represented by the general formula (II-2) is appropriately determined according to the use. The aromatic dicarboxylic acid unit in the polyamide resin (A) is a total of 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 the aromatic dicarboxylic acid unit. The content is preferably 70 mol% or more, more preferably 80 mol% or more, particularly preferably 90 mol% or more, and preferably 100 mol% or less. is there. Among these, it is preferable to contain isophthalic acid and / or terephthalic acid in the aromatic dicarboxylic acid unit. The content ratio of the isophthalic acid unit to the terephthalic acid unit (isophthalic acid unit / terephthalic acid unit) is not particularly limited and is appropriately determined according to the application. For example, from the viewpoint of reducing an appropriate glass transition temperature and crystallinity, when the total of both units is 100, the molar ratio is preferably 0/100 to 100/0, more preferably 0/100 to 60/40, More preferably, it is 0/100 to 40/60, and more preferably 0/100 to 30/70.

In the dicarboxylic acid unit in the polyamide resin (A), the content ratio of the linear aliphatic dicarboxylic acid unit to the aromatic dicarboxylic acid unit (linear aliphatic dicarboxylic acid unit / aromatic dicarboxylic acid unit) is particularly limited. Rather, it is determined appropriately according to the application. For example, when the purpose is to increase the glass transition temperature of the polyamide resin (A) to lower the crystallinity of the polyamide resin (A), the linear aliphatic dicarboxylic acid unit / aromatic dicarboxylic acid unit is both units. When the total of these is 100, 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. When the purpose is to lower the glass transition temperature of the polyamide resin (A) to give the polyamide resin (A) flexibility, the linear aliphatic dicarboxylic acid unit / aromatic dicarboxylic acid unit is When the total is 100, 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.

Examples of the compound that can constitute a dicarboxylic acid unit other than the dicarboxylic acid unit represented by the general formula (II-1) or (II-2) include oxalic acid, malonic acid, fumaric acid, maleic acid, 1,3- Examples thereof include, but are not limited to, dicarboxylic acids such as benzenediacetic acid and 1,4-benzenediacetic acid.

[Tertiary hydrogen-containing carboxylic acid unit]
In the present invention, the tertiary hydrogen-containing carboxylic acid unit in the polyamide resin (A) has at least one amino group and one carboxyl group from the viewpoint of polymerization of the polyamide resin (A), or two or more carboxyl groups. Have. Specific examples include structural units represented by any of the following general formulas (III), (IV), or (V).

[In the general formulas (III) to (V), R, R ¹ and R ² each represent a substituent, and A ¹ to A ³ each represent a single bond or a divalent linking group. However, the case where both A ¹ and A ² in the general formula (IV) are single bonds is excluded. ]

In the present invention, the polyamide resin (A) includes a tertiary hydrogen-containing carboxylic acid unit. By containing such a tertiary hydrogen-containing carboxylic acid unit as a copolymerization component, the polyamide resin (A) can exhibit excellent oxygen absorption performance without containing a transition metal.

In the present invention, the mechanism by which the polyamide resin (A) having a tertiary hydrogen-containing carboxylic acid unit exhibits good oxygen absorption performance has not yet been clarified, but is estimated as follows. In a compound that can constitute a tertiary hydrogen-containing carboxylic acid unit, an electron-withdrawing group and an electron-donating group are bonded to the same carbon atom, so that unpaired electrons existing on the carbon atom are energetic. It is considered that a very stable radical is generated by a phenomenon called a captodative effect that is stabilized in a stable manner. That is, the carboxyl group is an electron withdrawing group, and the carbon to which the adjacent tertiary hydrogen is bonded becomes electron deficient (δ ⁺ ), so the tertiary hydrogen also becomes electron deficient (δ ⁺ ) Dissociates as a radical. When oxygen and water are present here, it is considered that oxygen reacts with this radical to show oxygen absorption performance. It has also been found that the higher the humidity and temperature, the higher the reactivity.

In the general formulas (III) to (V), R, R ¹ and R ² each represent a substituent. Examples of the substituent represented by R, R ¹ and R ² in the present invention include a halogen atom (eg, chlorine atom, bromine atom, iodine atom), alkyl group (1 to 15, preferably 1 to 6). Linear, branched or cyclic alkyl groups having the following carbon atoms, for example, methyl group, ethyl group, n-propyl group, isopropyl group, t-butyl group, n-octyl group, 2-ethylhexyl group, cyclopropyl group, cyclopentyl Group), an alkenyl group (a linear, branched or cyclic alkenyl group having 2 to 10, preferably 2 to 6 carbon atoms, such as a vinyl group, an allyl group), an alkynyl group (2 to 10, preferably Alkynyl groups having 2 to 6 carbon atoms, such as ethynyl groups, propargyl groups), aryl groups (aryls having 6 to 16, preferably 6 to 10 carbon atoms) 1 to 12 groups obtained by removing one hydrogen atom from a group, for example, phenyl group, naphthyl group, heterocyclic group (5-membered or 6-membered aromatic or non-aromatic heterocyclic compound) , Preferably a monovalent group having 2 to 6 carbon atoms, such as 1-pyrazolyl group, 1-imidazolyl group, 2-furyl group, cyano group, hydroxyl group, nitro group, alkoxy group (1-10, Preferably a linear, branched or cyclic alkoxy group having 1 to 6 carbon atoms, such as a methoxy group, an ethoxy group, an aryloxy group (6-12, preferably 6-8 carbon atoms aryl) An oxy group, such as a phenoxy group, an acyl group (formyl group, 2-10, preferably an alkylcarbonyl group having 2-6 carbon atoms, or 7-12, preferably 7-9 carbon atoms. Arylcarbonyl group having, for example, acetyl group, pivaloyl group, benzoyl group), amino group (amino group, 1-10, preferably alkylamino group having 1-6 carbon atoms, 6-12, preferably Is an anilino group having 6 to 8 carbon atoms, or a heterocyclic amino group having 1 to 12, preferably 2 to 6 carbon atoms, such as an amino group, a methylamino group, an anilino group), a mercapto group An alkylthio group (an alkylthio group having 1 to 10, preferably 1 to 6 carbon atoms, such as a methylthio group, an ethylthio group), an arylthio group (6 to 12, preferably 6 to 8 carbon atoms). Arylthio groups having, for example, phenylthio groups), heterocyclic thio groups (for example, heterocyclic thio groups having 2 to 10, preferably 2 to 6 carbon atoms, such as - benzothiazolylthio group), an imido group (2 to 10, preferably an imido group having 4 to 8 carbon atoms, for example, N- succinimido group, N- phthalimido group).

Among these functional groups, those having a hydrogen atom may be further substituted with the above groups, for example, an alkyl group substituted with a hydroxyl group (for example, hydroxyethyl group), an alkyl group substituted with an alkoxy group (Eg, methoxyethyl group), an alkyl group substituted with an aryl group (eg, benzyl group), an aryl group substituted with an alkyl group (eg, p-tolyl group), an aryloxy group substituted with an alkyl group ( Examples thereof include, but are not limited to, 2-methylphenoxy group.
In addition, when a functional group is further substituted, the carbon number mentioned above shall not include the carbon number of the further substituent. For example, a benzyl group is regarded as a C 1 alkyl group substituted with a phenyl group, and is not regarded as a C 7 alkyl group substituted with a phenyl group. The following description of the number of carbon atoms shall be similarly understood unless otherwise specified.

In the general formulas (IV) and (V), A ¹ to A ³ each represents a single bond or a divalent linking group. However, the case where both A ¹ and A ² in the general formula (IV) are single bonds is excluded. Examples of the divalent linking group include linear, branched or cyclic alkylene groups (C 1-12, preferably C 1-4 alkylene groups such as methylene and ethylene groups), aralkylene groups (carbon numbers). Examples thereof include an aralkylene group having 7 to 30 carbon atoms, preferably 7 to 13 carbon atoms, such as a benzylidene group, and an arylene group (arylene group having 6 to 30 carbon atoms, preferably 6 to 15 carbon atoms such as a phenylene group). These may further have a substituent, and examples of the substituent include the functional groups exemplified above as substituents represented by R, R ¹ and R ² . Examples thereof include, but are not limited to, an arylene group substituted with an alkyl group (for example, a xylylene group).

In the present invention, the polyamide resin (A) preferably contains at least one structural unit represented by any one of the general formulas (III), (IV), and (V). Among these, from the viewpoint of improving the availability of raw materials and oxygen absorption, a carboxylic acid unit having tertiary hydrogen on the α-carbon (carbon atom adjacent to the carboxyl group) is more preferable, and is represented by the general formula (III). The structural unit is particularly preferred.

R in the general formula (III) is as described above. Among them, a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group are more preferable, and a substituted or unsubstituted C 1-6 carbon atom is more preferable. An alkyl group and a substituted or unsubstituted aryl group having 6 to 10 carbon atoms are more preferred, and a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms and a substituted or unsubstituted phenyl group are particularly preferred.
Specific examples of preferred R include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, 1-methylpropyl group, 2-methylpropyl group, hydroxymethyl group, 1- Examples thereof include, but are not limited to, a hydroxyethyl group, a mercaptomethyl group, a methylsulfanylethyl group, a phenyl group, a naphthyl group, a benzyl group, and a 4-hydroxybenzyl group. Among these, a methyl group, an ethyl group, an isopropyl group, a 2-methylpropyl group, and a benzyl group are more preferable.

The compounds that can constitute the structural unit represented by the general formula (III) include alanine, 2-aminobutyric acid, valine, norvaline, leucine, norleucine, tert-leucine, isoleucine, serine, threonine, cysteine, methionine, 2 -Alpha-amino acids such as phenylglycine, phenylalanine, tyrosine, histidine, tryptophan, proline and the like can be exemplified, but are not limited thereto.
In addition, examples of the compound that can constitute the structural unit represented by the general formula (IV) include β-amino acids such as 3-aminobutyric acid, which constitute the structural unit represented by the general formula (V). Examples of the compound that can be used include, but are not limited to, dicarboxylic acids such as methylmalonic acid, methylsuccinic acid, malic acid, and tartaric acid.
These may be any of D-form, L-form and racemate, or allo-form. Moreover, these can be used individually or in combination of 2 or more types.

Among these, α-amino acids having tertiary hydrogen in the α carbon are particularly preferable from the viewpoint of availability of raw materials and improvement of oxygen absorption. Among α-amino acids, alanine is most preferable from the viewpoints of ease of supply, inexpensive price, ease of polymerization, and low yellowness (YI) of the polymer. Since alanine has a relatively low molecular weight and a high copolymerization rate per 1 g of the polyamide resin (A), the oxygen absorption performance per 1 g of the polyamide resin (A) is good.

Further, the purity of the compound that can constitute the tertiary hydrogen-containing carboxylic acid unit is 95% or more from the viewpoint of the influence on the polymerization such as the delay of the polymerization rate and the influence on the quality such as the yellowness of the polymer. Preferably, it is 98.5% or more, more preferably 99% or more. Further, sulfate ions and ammonium ions contained as impurities are preferably 500 ppm or less, more preferably 200 ppm or less, and still more preferably 50 ppm or less.

[Ω-aminocarboxylic acid unit]
In the present invention, when the polyamide resin (A) needs flexibility or the like, in addition to the diamine unit, the dicarboxylic acid unit and the tertiary hydrogen-containing carboxylic acid unit, the polyamide resin (A) An ω-aminocarboxylic acid unit represented by the formula (X) may be further contained.

[In the general formula (X), p represents an integer of 2 to 18. ]
The content of the ω-aminocarboxylic acid unit is preferably from 0.1 to 49.9 mol%, more preferably from 3 to 40 mol%, still more preferably from 5 to 35, based on all constituent units of the polyamide resin (A). Mol%. However, the total of the diamine unit, dicarboxylic acid unit, tertiary hydrogen-containing carboxylic acid unit, and ω-aminocarboxylic acid unit does not exceed 100 mol%.
In the general formula (X), 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 (X) 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 6-aminohexanoic acid units and / or 12-aminododecanoic acid units in a total of 50 mol% or more in the ω-aminocarboxylic acid unit, and the content is More preferably, it is 70 mol% or more, More preferably, it is 80 mol% or more, More preferably, it is 90 mol% or more, Preferably it is 100 mol% or less.

[Polymerization degree of polyamide resin (A)]
The relative viscosity is used for the degree of polymerization of the polyamide resin (A). The preferred relative viscosity of the polyamide resin (A) is preferably 1.8 to 4.2, more preferably 1.9 to 4.0, and still more preferably 2 from the viewpoint of the strength and appearance of the molded product and molding processability. 0.0 to 3.8.
The relative viscosity here is 96% measured in the same manner as the dropping time (t) measured by dissolving a 1 g polyamide resin (A) in 100 mL of 96% sulfuric acid at 25 ° C. with a Canon Fenceke viscometer. It is the ratio of the drop time (t ₀ ) of sulfuric acid itself, and is represented by the following formula.
Relative viscosity = t / t ₀

[Terminal amino group concentration]
The oxygen absorption rate of the polyamide resin (A) and the oxidative deterioration of the polyamide resin (A) due to oxygen absorption can be controlled by changing the terminal amino group concentration of the polyamide resin (A). In the present invention, from the viewpoint of the balance between oxygen absorption rate and oxidative degradation, the terminal amino group concentration of the polyamide resin (A) is preferably in the range of 5 to 150 μeq / g, more preferably 10 to 100 μeq / g, still more preferably 15 ~ 80 μeq / g.

<Method for producing polyamide resin (A)>
The polyamide resin (A) includes a diamine component that can constitute the diamine unit, a dicarboxylic acid component that can constitute the dicarboxylic acid unit, and a tertiary hydrogen-containing carboxylic acid component that can constitute the tertiary hydrogen-containing carboxylic acid unit. And the ω-aminocarboxylic acid component that can constitute the ω-aminocarboxylic acid unit, if necessary, can be produced by polycondensation, and the degree of polymerization can be controlled by adjusting the polycondensation conditions and the like. it can. 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 (A) may be adjusted from 1.

Examples of the polycondensation method of the polyamide resin (A) 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 (A), and the polyamide resin (A) of the stable property is obtained.

[Reactive extrusion method]
In the reactive extrusion method, a polyamide composed of a diamine component and a dicarboxylic acid component (a polyamide corresponding to the precursor of the polyamide resin (A)) or a polyamide composed of a diamine component, a dicarboxylic acid component and an ω-aminocarboxylic acid component (polyamide resin (A And a tertiary hydrogen-containing carboxylic acid component are melt-kneaded with an extruder and reacted. This is a method of incorporating a tertiary hydrogen-containing carboxylic acid component into a polyamide skeleton by an amide exchange reaction. In order to sufficiently react, a screw suitable for reactive extrusion is used, and a twin screw extruder having a large L / D is used. It is preferable to use it. When producing a polyamide resin (A) containing a small amount of a tertiary hydrogen-containing carboxylic acid unit, it is a simple method and suitable.

[Pressure salt method]
The pressurized salt method is a method of performing melt polycondensation under pressure using a nylon salt as a raw material. Specifically, after preparing an aqueous nylon salt solution comprising a diamine component, a dicarboxylic acid component, a tertiary hydrogen-containing carboxylic acid component, and an ω-aminocarboxylic acid component as necessary, the aqueous solution is concentrated, Next, the temperature is raised under pressure, and polycondensation is performed while removing condensed water. While the inside of the can is gradually returned to normal pressure, the temperature is raised to about the melting point of polyamide resin (A) + 10 ° C. and held, and then further gradually reduced to −0.02 MPaG and kept at the same temperature. Continue polycondensation. When a constant stirring torque is reached, the inside of the can is pressurized to about 0.3 MPaG with nitrogen to recover the polyamide resin (A).
The pressurized salt method is useful when a volatile component is used as a monomer, and is a preferable polycondensation method when the copolymerization rate of the tertiary hydrogen-containing carboxylic acid component is high. In particular, it is suitable for producing a polyamide resin (A) containing 15 mol% or more of tertiary hydrogen-containing carboxylic acid units in all structural units of the polyamide resin (A). By using the pressurized salt method, transpiration of the tertiary hydrogen-containing carboxylic acid component can be prevented, and further, polycondensation between the tertiary hydrogen-containing carboxylic acid components can be suppressed, and the polycondensation reaction can proceed smoothly. Therefore, a polyamide resin (A) excellent in properties can be obtained.

[Normal pressure dropping method]
In the atmospheric pressure dropping method, a diamine component is continuously dropped into a mixture obtained by heating and melting a dicarboxylic acid component, a tertiary hydrogen-containing carboxylic acid component, and, if necessary, an ω-aminocarboxylic acid component under normal pressure. Then, polycondensation is performed while removing condensed water. The polycondensation reaction is performed 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 (A).
Compared with the pressurized salt method, the atmospheric pressure dropping method does not use water to dissolve the salt, so the yield per batch is large, and the reaction rate is not required for vaporization / condensation of raw material components. The process time can be shortened.

[Pressure drop method]
In the pressure drop method, first, a dicarboxylic acid component, a tertiary hydrogen-containing carboxylic acid component, and, if necessary, an ω-aminocarboxylic acid component are charged into a polycondensation can, and the components are agitated and melt mixed. To prepare. Next, the diamine component is continuously dropped into the mixture while the inside of the can is preferably pressurized to about 0.3 to 0.4 MPaG, and polycondensation is performed while removing condensed water. At this time, the polycondensation reaction is performed 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 (A). When the set molar ratio is reached, the dropping 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 (A) + 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 constant stirring torque is reached, the inside of the can is pressurized to about 0.3 MPaG with nitrogen to recover the polyamide resin (A).
Like the pressurized salt method, the pressure dropping method is useful when a volatile component is used as a monomer, and is a preferred polycondensation method when the copolymerization rate of the tertiary hydrogen-containing carboxylic acid component is high. . In particular, it is suitable for producing a polyamide resin (A) containing 15 mol% or more of tertiary hydrogen-containing carboxylic acid units in all structural units of the polyamide resin (A). By using the pressure dropping method, the transpiration of the tertiary hydrogen-containing carboxylic acid component can be prevented, and further, the polycondensation between the tertiary hydrogen-containing carboxylic acid components can be suppressed, and the polycondensation reaction can proceed smoothly. Therefore, a polyamide resin (A) excellent in 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. It is possible to obtain a polyamide resin (A) having a low yellowness, which can be suppressed.

[Process of increasing the degree of polymerization]
The polyamide resin (A) produced by the polycondensation method can be used as it is, but may be subjected to a step for further increasing the degree of polymerization. Further examples of the step of increasing the degree of polymerization include reactive extrusion in an extruder and solid phase polymerization. As a heating device used in solid phase polymerization, a continuous heating drying device, a tumble dryer, a conical dryer, a rotary drum heating device called a rotary dryer, etc., and a rotary blade inside a nauta mixer are provided. A conical heating device can be preferably used, but a known method and device can be used without being limited thereto. In particular, when solid-phase polymerization of the polyamide resin (A) is performed, the rotating drum type heating device in the above-described device can seal the inside of the system and perform polycondensation 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 (A), it is preferable to add a phosphorus atom-containing compound 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, hypophosphite metal salts such as sodium hypophosphite, potassium hypophosphite, lithium hypophosphite and the like are particularly preferable because they are highly effective in promoting amidation reaction and 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 1000 ppm, more preferably 1 to 600 ppm, still more preferably 5 to 400 ppm in terms of the phosphorus atom concentration in the polyamide resin (A). If it is 0.1 ppm or more, the polyamide resin (A) is difficult to be colored during the polymerization, and the transparency becomes high. If it is 1000 ppm or less, the polyamide resin (A) is hardly 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, so that the appearance of the molded product is improved.

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 (A). In order to prevent coloring of the polyamide resin (A) during the polycondensation, it is necessary to make a sufficient amount of the phosphorus atom-containing compound present. However, in some cases, the polyamide resin (A) 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. The ratio (molar ratio) between the phosphorus atom-containing compound and the alkali metal compound is such that the phosphorus atom-containing compound / alkali metal compound = 1.0 / 0.05 to 1.0 from the viewpoint of controlling the polymerization rate and reducing the yellowness. The range of 1.0 / 1.5 is preferable, more preferably 1.0 / 0.1 to 1.0 / 1.2, and still more preferably 1.0 / 0.2 to 1.0 / 1. 1.

2-2. Additive (B)
The oxygen absorption barrier layer of the present invention may further contain an additive (B) as necessary in addition to the polyamide resin (A) described above. One type of additive (B) may be used, or a combination of two or more types may be used. The content of the additive (B) in the oxygen absorption barrier layer is preferably 10% by mass or less, more preferably 5% by mass or less, although it depends on the type of additive.

[Anti-whitening agent]
In the present invention, it is preferable to add a diamide compound and / or a diester compound to the polyamide resin (A) as a suppression of whitening after the hot water treatment or after a long period of time. Diamide compounds and diester compounds are effective in suppressing whitening due to precipitation of oligomers. A diamide compound and a diester compound may be used alone or in combination.

The diamide compound used in the present invention is preferably a diamide compound obtained from an aliphatic dicarboxylic acid having 8 to 30 carbon atoms and a diamine having 2 to 10 carbon atoms. When the aliphatic dicarboxylic acid has 8 or more carbon atoms and the diamine has 2 or more carbon atoms, a whitening prevention effect can be expected. In addition, when the aliphatic dicarboxylic acid has 30 or less carbon atoms and the diamine has 10 or less carbon atoms, uniform dispersion in the oxygen-absorbing barrier layer is good. The aliphatic dicarboxylic acid may have a side chain or a double bond, but a linear saturated aliphatic dicarboxylic acid is preferred. One kind of diamide compound may be used, or two or more kinds may be used in combination.

Examples of the aliphatic dicarboxylic acid include stearic acid (C18), eicosanoic acid (C20), behenic acid (C22), montanic acid (C28), and triacontanoic acid (C30). Examples of the diamine include ethylenediamine, butylenediamine, hexanediamine, xylylenediamine, and bis (aminomethyl) cyclohexane. A diamide compound obtained by combining these is preferred.
A diamide compound obtained from a diamine composed mainly of an aliphatic dicarboxylic acid having 8 to 30 carbon atoms and mainly ethylenediamine, or a diamide compound obtained from an aliphatic dicarboxylic acid mainly composed of montanic acid and a diamine having 2 to 10 carbon atoms is particularly preferred. Is a diamide compound obtained from an aliphatic dicarboxylic acid mainly composed of stearic acid and a diamine mainly composed of ethylenediamine.

The diester compound used in the present invention is preferably a diester compound obtained from an aliphatic dicarboxylic acid having 8 to 30 carbon atoms and a diol having 2 to 10 carbon atoms. When the aliphatic dicarboxylic acid has 8 or more carbon atoms and the diol has 2 or more carbon atoms, an effect of preventing whitening can be expected. Further, when the aliphatic dicarboxylic acid has 30 or less carbon atoms and the diol has 10 or less carbon atoms, uniform dispersion in the oxygen-absorbing barrier layer is good. The aliphatic dicarboxylic acid may have a side chain or a double bond, but a linear saturated aliphatic dicarboxylic acid is preferred. One type of diester compound may be used, or two or more types may be used in combination.
Examples of the aliphatic dicarboxylic acid include stearic acid (C18), eicosanoic acid (C20), behenic acid (C22), montanic acid (C28), and triacontanoic acid (C30). Examples of the diol include ethylene glycol, propanediol, butanediol, hexanediol, xylylene glycol, and cyclohexanedimethanol. A diester compound obtained by combining these is preferred.
Particularly preferred are diester compounds obtained from an aliphatic dicarboxylic acid mainly composed of montanic acid and a diol mainly composed of ethylene glycol and / or 1,3-butanediol.

In the present invention, the amount of the diamide compound and / or diester compound added is preferably 0.005 to 0.5% by mass, more preferably 0.05 to 0.5% by mass, and still more preferably in the oxygen absorption barrier layer. 0.12 to 0.5% by mass. A synergistic effect of preventing whitening can be expected by adding 0.005% by mass or more to the oxygen absorption barrier layer and using it together with the crystallization nucleating agent. Moreover, it becomes possible to keep the fog value of the molded object obtained by shape | molding the polyamide resin (A) of this invention low as the addition amount is 0.5 mass% or less in an oxygen absorption barrier layer.

[Layered silicate]
In the present invention, the oxygen absorption barrier layer may contain a layered silicate. By adding layered silicate, not only oxygen gas barrier property but also barrier property against gas such as carbon dioxide gas can be imparted to the paper container.

The layered silicate is a 2-octahedron or 3-octahedral layered silicate having a charge density of 0.25 to 0.6. Examples of the 2-octahedron type include montmorillonite, beidellite, and the like. Examples of the octahedron type include hectorite and saponite. Among these, montmorillonite is preferable.

It is preferable that the layered silicate is obtained by expanding an interlayer of the layered silicate by previously bringing an organic swelling agent such as a polymer compound or an organic compound into contact with the layered silicate. As the organic swelling agent, a quaternary ammonium salt can be preferably used. Preferably, a quaternary ammonium salt having at least one alkyl group or alkenyl group having 12 or more carbon atoms is used.

Specific examples of organic swelling agents include trimethyl dodecyl ammonium salts, trimethyl tetradecyl ammonium salts, trimethyl hexadecyl ammonium salts, trimethyl octadecyl ammonium salts, trimethyl alkyl ammonium salts such as trimethyl eicosyl ammonium salts; trimethyl octadecenyl ammonium salts Trimethylalkenylammonium salts such as trimethyloctadecadienylammonium salt; triethylalkylammonium salts such as triethyldodecylammonium salt, triethyltetradecylammonium salt, triethylhexadecylammonium salt, triethyloctadecylammonium salt; tributyldodecylammonium salt, tributyltetradecyl Ammonium salt, tributyl hexadecyl ammonium salt, Tributylalkylammonium salts such as butyloctadecylammonium salt; dimethyldialkylammonium salts such as dimethyldidodecylammonium salt, dimethylditetradecylammonium salt, dimethyldihexadecylammonium salt, dimethyldioctadecylammonium salt, dimethylditallowammonium salt; dimethyl Dioctadecenyl ammonium salt, dimethyl dialkenyl ammonium salt such as dimethyl dioctadecadienyl ammonium salt; diethyl didodecyl ammonium salt, diethyl ditetradecyl ammonium salt, diethyl dihexadecyl ammonium salt, diethyl dioctadecyl ammonium salt, etc. Diethyl dialkyl ammonium salt; dibutyl didodecyl ammonium salt, dibutyl ditetradecyl ammonium salt, di Dibutyl dialkyl ammonium salts such as til dihexadecyl ammonium salt and dibutyl dioctadecyl ammonium salt; methyl benzyl dialkyl ammonium salts such as methyl benzyl dihexadecyl ammonium salt; dibenzyl dialkyl ammonium salts such as dibenzyl dihexadecyl ammonium salt; Trialkylmethylammonium salts such as dodecylmethylammonium salt, tritetradecylmethylammonium salt, trioctadecylmethylammonium salt; trialkylethylammonium salts such as tridodecylethylammonium salt; trialkylbutylammonium salts such as tridodecylbutylammonium salt 4-amino-n-butyric acid, 6-amino-n-caproic acid, 8-aminocaprylic acid, 10-aminodecanoic acid, 12-aminodo Examples thereof include omega-amino acids such as decanoic acid, 14-aminotetradecanoic acid, 16-aminohexadecanoic acid, 18-aminooctadecanoic acid and the like. In addition, hydroxyl group and / or ether group-containing ammonium salts, among them, methyl dialkyl (PAG) ammonium salt, ethyl dialkyl (PAG) ammonium salt, butyl dialkyl (PAG) ammonium salt, dimethyl bis (PAG) ammonium salt, diethyl bis (PAG) ) Ammonium salt, dibutyl bis (PAG) ammonium salt, methyl alkyl bis (PAG) ammonium salt, ethyl alkyl bis (PAG) ammonium salt, butyl alkyl bis (PAG) ammonium salt, methyl tri (PAG) ammonium salt, ethyl tri (PAG) ammonium Salt, butyltri (PAG) ammonium salt, tetra (PAG) ammonium salt (wherein alkyl is carbon number such as dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, etc.) A quaternary ammonium containing at least one alkylene glycol residue such as a polyalkylene glycol residue, preferably a polyethylene glycol residue or a polypropylene glycol residue having 20 or less carbon atoms). Salts can also be used as organic swelling agents. Among them, trimethyldodecyl ammonium salt, trimethyl tetradecyl ammonium salt, trimethyl hexadecyl ammonium salt, trimethyl octadecyl ammonium salt, dimethyl didodecyl ammonium salt, dimethyl ditetradecyl ammonium salt, dimethyl dihexadecyl ammonium salt, dimethyl dioctadecyl ammonium salt, dimethyl A ditallow ammonium salt is preferred. These organic swelling agents can be used alone or as a mixture of a plurality of types.

In the present invention, a layered silicate treated with an organic swelling agent is preferably added in an amount of 0.5 to 8% by mass in the oxygen absorption barrier layer, more preferably 1 to 6% by mass, still more preferably 2 to 5% by mass. If the amount of layered silicate added is 0.5% by mass or more, the effect of improving the gas barrier property is sufficiently obtained, and if it is 8% by mass or less, pinholes are generated due to deterioration of the flexibility of the oxygen absorption barrier layer. Such problems are unlikely to occur.

In the oxygen absorption barrier layer, the layered silicate is preferably uniformly dispersed without locally agglomerating. The uniform dispersion here means that the layered silicate is separated into a flat plate in the oxygen absorption barrier layer, and 50% or more of them have an interlayer distance of 5 nm or more. Here, the interlayer distance refers to the distance between the centers of gravity of the flat objects. The larger the distance, the better the dispersion state, the better the appearance such as transparency, and the better the gas barrier properties such as oxygen and carbon dioxide.

[Oxidation reaction accelerator]
In order to further enhance the oxygen absorption performance of the oxygen absorption barrier layer, 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 enhance the oxygen absorption performance of the oxygen absorption barrier layer by promoting the oxygen absorption performance of the polyamide resin (A). 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 thereof 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. Among these, a cobalt salt excellent in an oxygen reaction promoting effect or a combination of a cobalt salt and a manganese salt is preferable.
In the present invention, the addition amount of the oxygen reaction accelerator is preferably 10 to 800 ppm, more preferably 50 to 600 ppm, and still more preferably 100 to 400 ppm as the metal atom concentration in the oxygen absorption barrier layer.

[Oxygen absorber]
In order to further enhance the oxygen absorption performance of the oxygen absorption barrier layer, a conventionally known oxygen absorbent may be added within a range not impairing the effects of the present invention. The oxygen absorbent can enhance the oxygen absorption performance of the oxygen absorption barrier layer by imparting oxygen absorption performance to the oxygen absorption barrier layer separately from the oxygen absorption performance of the polyamide resin (A). Examples of the oxygen absorbent 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 oxygen absorber added is preferably 0.01 to 5% by mass, more preferably 0.1 to 4% by mass, and still more preferably 0.5 to 3% by mass in the oxygen absorption barrier layer. is there.

[Anti-gelling / Fish Eye Reducing Agent]
In the present invention, it is preferable to add one or more carboxylates selected from sodium acetate, calcium acetate, magnesium acetate, calcium stearate, magnesium stearate, sodium stearate and derivatives thereof. Examples of the derivatives include 12-hydroxystearic acid metal salts such as calcium 12-hydroxystearate, magnesium 12-hydroxystearate, and sodium 12-hydroxystearate. By adding the carboxylates, it is possible to prevent the gelation of the polyamide resin (A) that occurs during the molding process and to reduce fish eyes in the molded article, thereby improving the suitability of the molding process.

The addition amount of the carboxylates is preferably 400 to 10000 ppm, more preferably 800 to 5000 ppm, still more preferably 1000 to 3000 ppm as the concentration in the oxygen absorption barrier layer. If it is 400 ppm or more, the thermal deterioration of the polyamide resin (A) can be suppressed, and gelation can be prevented. Moreover, if it is 10000 ppm or less, a polyamide resin (A) will not raise | generate a shaping | molding defect, and neither coloring nor whitening will occur. It is speculated that the presence of carboxylates that are basic substances in the melted polyamide resin (A) delays the modification of the polyamide resin (A) by heat and suppresses the formation of a gel that is considered to be the final modified product. The
The carboxylates described above are excellent in handling properties, and among them, metal stearate is preferable because it is inexpensive and has an effect as a lubricant, and can stabilize the molding process. Further, the shape of the carboxylate is not particularly limited, but when the powder and the smaller particle size are dry-mixed, it is easy to uniformly disperse in the oxygen absorption barrier layer. Is preferably 0.2 mm or less.

[Antioxidant]
In the present invention, it is preferable to add an antioxidant from the viewpoint of controlling oxygen absorption performance 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.

Specific examples of the hindered phenol antioxidant include triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate, 4,4′-butylidenebis (3-methyl- 6-t-butylphenol), 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,4-bis- (n-octylthio) -6- (4-Hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- ( , 5-di-t-butyl-4-hydroxyphenyl) propionate, 2,2-thiobis (4-methyl-6-butylphenol), N, N′-hexamethylenebis (3,5-di-t- Butyl-4-hydroxy-hydroxycinnamamide), 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,3 5-di-butyl-4-hydroxybenzyl) benzene, ethyl calcium bis (3,5-di-t-butyl-4-hydroxybenzylsulfonate, tris- (3,5-di-t-butyl-4-hydroxy) Benzyl) -isocyanurate, 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylpheno , Stearyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis- (4-methyl-6-t-butylphenol), 2,2'-methylene- Bis- (4-ethyl-6-tert-butylphenol), 4,4′-thiobis- (3-methyl-6-tert-butylphenol), octylated diphenylamine, 2,4-bis [(octylthio) methyl] -O -Cresol, isooctyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 4,4'-butylidenebis (3-methyl-6-tert-butylphenol, 3,9-bis [1, 1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] -2,4,8,10-tetrao Saspiro [5,5] undecane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3 , 5-di-tert-butyl-4-hydroxybenzyl) benzene, bis [3,3′-bis- (4′-hydroxy-3′-tert-butylphenyl) butyric acid] glycol ester, 1,3, 5-tris (3 ′, 5′-di-t-butyl-4′-hydroxybenzyl) -sec-triazine-2,4,6- (1H, 3H, 5H) trione, d-α-tocopherol, etc. It is done. These can be used alone or as a mixture thereof. Specific examples of commercially available hindered phenol compounds include Irganox 1010 and Irganox 1098 manufactured by BASF (both are trade names).

Specific examples of phosphorus antioxidants include triphenyl phosphite, trioctadecyl phosphite, tridecyl phosphite, trinonylphenyl phosphite, diphenylisodecyl phosphite, bis (2,6-di-tert-butyl- 4-methylphenyl) pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, tris (2,4-di-tert-butylphenyl) phosphite, distearyl pentaerythritol And organic phosphorus compounds such as diphosphite, tetra (tridecyl-4,4′-isopropylidene diphenyl diphosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, etc. Want to be alone It can be used in a mixture thereof.

The content of the antioxidant can be used without particular limitation as long as it does not impair the various performances of the composition, but it is preferable in the oxygen-absorbing barrier layer from the viewpoint of controlling the oxygen-absorbing performance and suppressing deterioration of mechanical properties. Is 0.001 to 3 mass%, more preferably 0.01 to 1 mass%.

[Other additives]
Depending on the required application and performance, the oxygen-absorbing barrier layer has a lubricant, matting agent, heat stabilizer, weathering stabilizer, ultraviolet absorber, plasticizer, flame retardant, antistatic agent, anti-coloring agent, crystal An additive such as a nucleating agent may be added. These additives can be added as necessary within a range not impairing the effects of the present invention.

3. Optional layer 3-1. Fusing Layer In the present invention, the laminated material preferably further includes a fusing layer on the surface (one side surface or both side surfaces) of the laminated material in addition to the paper base material layer and the oxygen absorbing barrier layer. The paper container formed by boxing the laminated material having the fusion layer has the fusion layer as the innermost layer and / or the outermost layer of the paper container. The fusing layer is a layer containing a thermoplastic resin having a fusing property, and is heat-sealed when a laminated material is boxed to form a container.
As the thermoplastic resin having the fusibility, various polyolefin resins that can be melted by heat and fused to each other, other thermoplastic resins, and the like can be used. For example, low density polyethylene, medium density polyethylene, High density polyethylene, linear (linear) low density polyethylene, ethylene-α / olefin copolymer polymerized using metallocene catalyst, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer Polymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, methylpentene polymer, polybutene polymer, polyvinyl acetate resin, poly (meth) acrylic resin, polychlorinated Polyolefin such as vinyl resin, polyethylene or polypropylene Acid-modified polyolefin resins modified with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, etc., may be used alone Two or more kinds of materials may be mixed. Among these, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear (linear) low-density polyethylene, and ethylene-α · polymerized using a metallocene catalyst from the viewpoint of moldability, hygiene, odor, etc. Olefin copolymers are preferably used.
In addition, the fused layer is a lubricant, crystallization nucleating agent, anti-whitening agent, matting agent, heat stabilizer, weathering stabilizer, ultraviolet absorber, plasticizer, flame retardant, antistatic agent, coloring as long as the effect is not impaired. Additives such as inhibitors, antioxidants, impact resistance improvers and the like may be included.
In addition, when the fusion layer is provided on both surfaces of the laminated material, the structure of both the fusion layers may be different from each other, but it is stable fusion property that the thermoplastic resin as the main component is the same. Is preferable.

The thickness of the fusion layer in the present invention is preferably from 5 to 200 μm, more preferably from the viewpoint of ensuring workability when boxing the laminated material while exhibiting practical fusion strength. The thickness is 10 to 150 μm, more preferably 15 to 100 μm.

3-2. Adhesive layer In the present invention, the laminate may further include an adhesive layer in addition to the paper base layer and the oxygen-absorbing barrier layer. In a laminated material, when a practical interlayer adhesive strength cannot be obtained between two adjacent layers (for example, an oxygen absorption barrier layer and a fusion layer), an adhesive layer is provided between the two layers. Is preferred.
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. It is preferable to select a modified resin of the same type as the thermoplastic resin having a fusibility as the thermoplastic resin having 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 workability when making a laminated material while exhibiting practical adhesive strength. ~ 80 μm.

3-3. Other Arbitrary Layers In the present invention, the laminated material may further include an optional layer other than those described above depending on the desired performance and the like. For example, a method in which a polyethylene layer is provided between the oxygen absorption barrier layer and the paper substrate to lower the extrusion processing temperature of the oxygen absorption barrier layer and prevent thermal deterioration during the extrusion processing is preferably performed. In addition to this, as a material constituting an arbitrary layer for imparting various performances, the above-mentioned various polyolefins, various polyamides such as nylon 6 and nylon MXD6, various polyesters such as polyethylene terephthalate and polyglycolic acid, The thing which mixed thermoplastic resins, such as an ethylene vinyl alcohol copolymer, individually or mixed is mentioned. In addition, various metal foils, resin films on which metal oxide films are deposited, and the like can also be used.

4). Manufacturing method of laminated material As a method of manufacturing a laminated material, a method of laminating a normal packaging material, for example, a wet lamination method, a dry lamination method, a solventless dry lamination method, an extrusion lamination method, a T-die coextrusion molding method , Coextrusion lamination, inflation, etc. Furthermore, in the present invention, when performing the above-mentioned lamination, for example, pretreatment such as corona treatment and ozone treatment can be applied to a film or the like, if necessary, for example, isocyanate (urethane), polyethylene Anchor anchors such as imine, polybutadiene, and organic titanium, or known anchors such as polyurethane, polyacrylic, polyester, epoxy, polyvinyl acetate, cellulose, and other adhesives for laminating A coating agent, an adhesive, etc. can be used.

<< Paper container >>
The paper container of this invention is a paper container formed by boxing the laminated material mentioned above.
In the paper container of the present invention, the laminated material is part or all of the constituent material. The paper container including all of the laminated material means a paper container composed only of the laminated material, and the paper container including the laminated material as a part of the constituent material is a part of the paper container of the laminated material. The rest means a paper container made of other materials. As an example of the latter, there is a paper container configured so that a stored material can be easily confirmed by using a transparent material (for example, a state in which the paper base material layer is removed from the laminated material) in part.
The shape of the paper container according to the present invention is not particularly limited as long as it can store and store various commonly known articles such as a columnar shape, a prismatic shape, a truncated cone shape, and a prismatic shape. Further, the capacity of the container is not particularly limited, and can be selected within an appropriate range according to the article to be stored and stored.

In the present invention, a method for making a laminated material can be appropriately selected according to the shape of the paper container. For example, a blank plate for a paper container having a predetermined shape subjected to ruled line processing or the like using a laminated material is punched out, and then the body edge of the blank plate is overlapped, and the overlapping end portion is welded to form a cylindrical body portion. Form. Next, the cylindrical body formed as described above is attached to the filling and packaging machine, and the bottom part is folded and heat-sealed using a predetermined ruled line to form the bottom, and then from the top of the opening A paper container can be manufactured by filling the contents, and then folding and heat-sealing the top using a predetermined ruled line to form a roof having a palm portion, a so-called govel top-shaped top. it can. In addition, the manufacturing method of the paper container of this invention is not limited to this, For example, what is called a brick top type | mold paper container which made the top part flat can also be manufactured using various methods.

The paper container of the present invention is suitable for filling and packaging various articles because it has excellent oxygen absorption performance and oxygen barrier performance and excellent flavor retention of contents. For example, beverages such as milk, dairy products, juices, alcoholic beverages, coffee, teas, seasonings, soups, and other various liquid foods, as well as chemicals such as adhesives, adhesives, agricultural chemicals, insecticides, pharmaceuticals, It can be used for filling and packaging goods such as cosmetics, shampoos, rinses, detergents and other miscellaneous goods.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.
In the following examples, regarding the units constituting the copolymer,
The unit derived from metaxylylenediamine is “MXDA”,
A unit derived from 1,3-bis (aminomethyl) cyclohexane is referred to as “1,3BAC”,
The unit derived from hexamethylenediamine is “HMDA”,
The unit derived from adipic acid is “AA”,
The unit derived from isophthalic acid is “IPA”,
The unit derived from DL-alanine is “DL-Ala”,
The unit derived from DL-leucine is “DL-Leu”,
The unit derived from DL-valine is “DL-Val”,
A unit derived from ε-caprolactam is referred to as “ε-CL”.
Polymetaxylylene adipamide is referred to as “N-MXD6”.

The α-amino acid content, relative viscosity, terminal amino group concentration, glass transition temperature and melting point of the polyamide resin obtained in Production Example were measured by the following methods. Moreover, the film was produced from the polyamide resin obtained by the manufacture example, and the oxygen absorption amount was measured with the following method.

(1) α-Amino Acid Content Rate Using ¹ H-NMR (400 MHz, manufactured by JEOL Ltd., trade name: JNM-AL400, measurement mode: NON ( ¹ H)), α-amino acid content rate of polyamide resin Quantification was performed. Specifically, a 5 mass% solution of polyamide resin was prepared using formic acid-d as a solvent, and ¹ H-NMR measurement was performed.

(2) Relative viscosity 1 g of a pellet sample was precisely weighed and dissolved in 100 ml of 96% sulfuric acid at 20-30 ° C. with stirring. After completely dissolving, 5 ml of the solution was quickly taken into a Cannon-Fenceke viscometer and allowed to stand for 10 minutes in a constant temperature bath at 25 ° C., and then the drop 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

(3) Terminal amino group concentration [NH ₂ ]
The polyamide resin is precisely weighed and dissolved in a phenol / ethanol = 4/1 volume solution by stirring at 20-30 ° C. After complete dissolution, the inner wall of the container is washed with 5 ml of methanol while stirring, and 0.01 mol / L hydrochloric acid is dissolved. The terminal amino group concentration [NH ₂ ] was determined by neutralization titration with an aqueous solution.

(4) Glass transition temperature and melting point DSC measurement using a differential scanning calorimeter (manufactured by Shimadzu Corporation, trade name: DSC-60) under a nitrogen stream at a rate of temperature increase of 10 ° C./minute (differential scanning calorimetry) The glass transition temperature (Tg) and the melting point (Tm) were determined.

(5) Oxygen absorption amount Using a 30mmφ twin screw extruder (manufactured by Plastic Engineering Laboratory Co., Ltd.) equipped with a T die, the thickness of the polyamide resin was increased from the polyamide resin at a cylinder T die temperature of (polyamide resin melting point + 20 ° C) An unstretched single layer film having a thickness of about 100 μm was formed.
Two test pieces of 10 cm x 10 cm cut out from the produced unstretched single layer film were charged into a 25 cm x 18 cm three-side sealed bag made of an aluminum foil laminated film together with cotton containing 10 ml of water, and the amount of air in the bag Was sealed to 400 ml. The humidity in the bag was 100% RH (relative humidity). After storing at 40 ° C. for 7 days, 14 days, and 28 days, the oxygen concentration in the bag was measured with an oxygen concentration meter (trade name: LC-700F, manufactured by Toray Engineering Co., Ltd.). The amount of oxygen absorbed was calculated from the oxygen concentration.

Production Example 1 (Production of polyamide resin 1)
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 (88.96 mol), DL-alanine (Musashino Chemical Laboratory Co., Ltd.) 880.56 g (9.88 mol), sodium hypophosphite 11.7 g (0. 11 mol) and 6.06 g (0.074 mol) of sodium acetate were added, and after sufficiently purging with nitrogen, the inside of the reaction vessel was sealed, and the temperature was raised to 170 ° C. with stirring while keeping the inside of the vessel at 0.4 MPa. After reaching 170 ° C., dropping of 12082.2 g (88.71 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, While maintaining 0.4 MPa, the temperature inside the reaction vessel was continuously raised to 240 ° C. while removing the condensed water produced outside the system. 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 Then, it was cooled and pelletized with a pelletizer to obtain an MXDA / AA / DL-Ala copolymer (polyamide resin 1). The composition ratio of each monomer was metaxylylenediamine: adipic acid: DL-alanine = 47.3: 47.4: 5.3 (mol%).

Production Example 2 (Production of polyamide resin 2)
MXDA / AA in the same manner as in Production Example 1 except that the composition ratio of each monomer was metaxylylenediamine: adipic acid: DL-alanine = 44.4: 44.5: 11.1 (mol%). / DL-Ala copolymer (polyamide resin 2) was obtained.

Production Example 3 (Production of polyamide resin 3)
MXDA / AA in the same manner as in Production Example 1 except that the charged composition ratio of each monomer was metaxylylenediamine: adipic acid: DL-alanine = 41.1: 41.3: 17.6 (mol%). / DL-Ala copolymer (polyamide resin 3) was obtained.

Production Example 4 (Production of polyamide resin 4)
MXDA / AA in the same manner as in Production Example 1 except that the charged composition ratio of each monomer was metaxylylenediamine: adipic acid: DL-alanine = 37.5: 37.5: 25.0 (mol%). / DL-Ala copolymer (polyamide resin 4) was obtained.

Production Example 5 (Production of polyamide resin 5)
MXDA / AA in the same manner as in Production Example 1 except that the charged composition ratio of each monomer was metaxylylenediamine: adipic acid: DL-alanine = 33.3: 33.4: 33.3 (mol%). / DL-Ala copolymer (polyamide resin 5) was obtained.

Production Example 6 (Production of polyamide resin 6)
The α-amino acid was changed to DL-leucine (manufactured by Ningbo Haishu Bio-technology), and the composition ratio of each monomer was changed to metaxylylenediamine: adipic acid: DL-leucine = 44.3: 44.6: 11.1. An MXDA / AA / DL-Leu copolymer (polyamide resin 6) was obtained in the same manner as in Production Example 1 except that the amount was (mol%).

Production Example 7 (Production of polyamide resin 7)
The α-amino acid was changed to DL-valine (manufactured by Sinogel Amino Acid Co., Ltd.), and the composition ratio of each monomer was changed to metaxylylenediamine: adipic acid: DL-valine = 44.3: 44.6: 11. Except that the content was 0.1 (mol%), an MXDA / AA / DL-Val copolymer (polyamide resin 7) was obtained in the same manner as in Production Example 1.

Production Example 8 (Production of polyamide resin 8)
The dicarboxylic acid component was changed to a mixture of isophthalic acid (manufactured by EI International Chemical Co., Ltd.) and adipic acid, and the composition ratio of each monomer was changed to metaxylylenediamine: adipic acid: isophthalic acid: DL- MXDA / AA / IPA / DL-Ala copolymer (polyamide resin 8) in the same manner as in Production Example 1 except that alanine = 44.3: 39.0: 5.6: 11.1 (mol%) Got.

Production Example 9 (Production of polyamide resin 9)
Ε-Caprolactam (manufactured by Ube Industries, Ltd.) was used as a comonomer, α-amino acid was changed to DL-leucine, and the composition ratio of each monomer was changed to metaxylylenediamine: adipic acid: DL-leucine: ε- MXDA / AA / DL-Leu / ε-CL copolymer (polyamide resin) in the same manner as in Production Example 1 except that caprolactam = 41.0: 41.3: 11.8: 5.9 (mol%) 9) was obtained.

Production Example 10 (Production of polyamide resin 10)
The diamine component was changed to a mixture of 1,3-bis (aminomethyl) cyclohexane (Mitsubishi Gas Chemical Co., Ltd.) and metaxylylenediamine, and the charged composition ratio of each monomer was changed to metaxylylenediamine: 1,3- MXDA / 1,3BAC in the same manner as in Production Example 1 except that bis (aminomethyl) cyclohexane: adipic acid: DL-alanine = 33.2: 11.1: 44.6: 11.1 (mol%) / AA / DL-Ala copolymer (polyamide resin 10) was obtained.

Production Example 11 (Production of polyamide resin 11)
The diamine component was changed to a mixture of hexamethylenediamine (manufactured by Showa Chemical Co., Ltd.) and metaxylylenediamine, and the composition ratio of each monomer was changed to metaxylylenediamine: hexamethylenediamine: adipic acid: DL-alanine = 33. .3: 11.1: 44.5: 11.1 (mol%) was obtained in the same manner as in Production Example 1 to obtain an MXDA / HMDA / AA / DL-Ala copolymer (polyamide resin 11). .

Production Example 12 (Production of polyamide resin 12)
N-MXD6 was prepared in the same manner as in Production Example 1 except that DL-alanine was not added and the charged composition ratio of each monomer was metaxylylenediamine: adipic acid = 49.8: 50.2 (mol%). (Polyamide resin 12) was obtained.

Production Example 13 (Production of polyamide resin 13)
N-MXD6 was prepared in the same manner as in Production Example 1 except that DL-alanine was not added and the charged composition ratio of each monomer was metaxylylenediamine: adipic acid = 50.2: 49.8 (mol%). (Polyamide resin 13) was obtained.

Table 1 shows the charged monomer composition of polyamide resins 1 to 13 and the measurement results of α-amino acid content, relative viscosity, terminal amino group concentration, glass transition temperature, melting point, and oxygen absorption amount of the obtained polyamide resin.

Next, in Examples 1 to 15 and Comparative Examples 1 to 4, a laminated material was produced using the polyamide resins 1 to 13, and a paper container was produced from the laminated material.

Example 1
Using an extrusion laminator comprising an extruder, a T-die, a cooling roll, a corona treatment machine, and a take-up machine, one side of a paper substrate having a basis weight of 400 g / m ² was subjected to corona treatment, and then the low-density polyethylene ( A product made by Nippon Polyethylene Co., Ltd., trade name: Novatec LD LC602A, hereinafter abbreviated as LDPE) is extruded and laminated to a thickness of 30 μm, and the other surface of the paper base material is subjected to corona treatment to obtain LDPE. A laminate having a layer / paper substrate layer configuration was produced.
Next, using the first to third extruders, the feed block, the T die, the cooling roll, and the winder, a coextrusion apparatus is used to produce LDPE from the first extruder and Production Example 1 from the second extruder. Extruded Polyamide 1 and Adhesive Polyethylene (Mitsubishi Chemical Co., Ltd., trade name: Modic L504, hereinafter abbreviated as Adhesive PE) were extruded from the third extruder, LDPE layer / Adhesive PE layer / Polyamide resin layer Co-extrusion laminating so that the LDPE layer is laminated on the corona surface of the paper base that is formed by extrusion laminating the LDPE in advance. Thus, a laminated material was obtained. The structure of the obtained laminated material is as follows: LDPE layer (30 μm) / adhesive PE layer (10 μm) / polyamide resin layer (20 μm) / adhesive PE layer (10 μm) / LDPE layer (30 μm) from the inner surface of the container / Paper base material layer / LDPE layer (30 μm).
Next, after applying an anti-heat sealant to the portion corresponding to the opening, the laminated material was ruled using a punching die and punched to obtain a blank plate. Were heat-welded to form a sleeve, and the sleeve was used in a molding and filling machine to produce a 500 ml internal capacity container with a capacity of 500 ml.

Examples 2 to 11
A paper container was produced in the same manner as in Example 1 except that polyamide resins 2 to 11 were used in place of the polyamide resin 1 for the polyamide resin layer.

Example 12
Using an extrusion laminator consisting of an extruder, a T die, a cooling roll, a corona treatment machine, and a take-up machine, one side of a paper base having a basis weight of 400 g / m ² was subjected to corona treatment, and then LDPE was applied to the corona surface with 30 μm. Extrusion lamination was performed to obtain a thickness, and the other surface of the paper substrate was subjected to corona treatment to produce a laminate having a structure of LDPE layer / paper substrate layer.
Next, by using a co-extrusion apparatus comprising a first to third extruder, a feed block, a T die, a cooling roll and a winder, the first extruder is used for LDPE, the second extruder is used for polyamide resin 1, 3. Adhesive PE was extruded from the extruder 3 and a multilayer molten state was formed through a feed block so that the order of LDPE layer / adhesive PE layer / polyamide resin layer was reached. A laminate was obtained by coextrusion lamination so that the polyamide resin layer was laminated on the corona surface. The composition of the obtained laminated material was LDPE layer (50 μm) / adhesive PE layer (15 μm) / polyamide resin layer (25 μm) / paper base material layer / LDPE layer (30 μm) from the inner surface of the container. .
Next, after applying an anti-heat sealant to the portion corresponding to the opening, the laminated material was ruled using a punching die and punched to obtain a blank plate. Were heat-welded to form a sleeve, and the sleeve was used in a molding and filling machine to produce a 500 ml internal capacity container with a capacity of 500 ml.

Examples 13-15
A paper container was produced in the same manner as in Example 12 except that polyamide resins 2 to 4 were used in place of the polyamide resin 1 in the polyamide resin layer.

Comparative Example 1
A paper container was produced in the same manner as in Example 1 except that the polyamide resin 12 was used instead of the polyamide resin 1 for the polyamide resin layer.

Comparative Example 2
In the same manner as in Example 1, except that the polyamide resin layer was prepared by dry blending 100 parts by mass of polyamide resin 12 and 0.21 parts by mass of cobalt stearate (II) instead of polyamide resin 1. A container was prepared.

Comparative Example 3
Instead of the polyamide resin 1, 100 parts by weight of the polyamide resin 13, 0.15 parts by weight of cobalt stearate (II) and 3 parts by weight of maleic acid-modified polybutadiene (manufactured by Nippon Petrochemical Co., Ltd., trade name) A paper container was prepared in the same manner as in Example 1 except that a dry blend of M-2000-20) was used.

Comparative Example 4
Dry blend of 40 parts by mass of granular oxygen absorbent coated with 3 parts by mass of calcium chloride and 100 parts by mass of LDPE with respect to 100 parts by mass of reduced iron powder having an average particle size of 30 μm, followed by extrusion with a 35 mm twin screw extruder, After cooling with a net belt with a blower, LDPE containing oxygen absorbent was obtained through a pelletizer.
Next, using an extrusion laminator composed of an extruder, a T-die, a cooling roll, a corona treatment machine, and a take-up machine, one side of a paper substrate having a basis weight of 400 g / m ² was subjected to corona treatment, and then the LDPE was applied to the corona surface. Was laminated by extrusion to give a thickness of 30 μm, and the other side of the paper substrate was subjected to corona treatment to produce a laminate having a structure of LDPE layer / paper substrate layer.
Next, using a co-extrusion apparatus consisting of a first to fifth extruder, a feed block, a T die, a cooling roll, and a winder, the first extruder contains LDPE, and the second extruder contains the oxygen absorbent. LDPE, adhesive PE from the third extruder, polyamide resin 12 obtained in Production Example 12 from the fourth extruder, LDPE extruded from the fifth extruder, LDPE layer (A) / LDPE layer containing oxygen absorbent A corona surface of a paper base material in which a multilayer molten state is formed through a feed block in the order of / adhesive PE layer / polyamide resin layer / adhesive PE layer / LDPE layer (B), and LDPE is extruded and laminated in advance. The laminate was obtained by coextrusion lamination so that the LDPE layer (B) was laminated thereon. The structure of the obtained laminated material is as follows: LDPE layer (A) (50 μm) / oxygen absorbent-containing LDPE layer (50 μm) / adhesive PE layer (10 μm) / polyamide resin layer (20 μm) / Adhesive PE layer (10 μm) / LDPE layer (B) (20 μm) / paper substrate layer / LDPE layer (30 μm).
Next, after applying an anti-heat sealant to the portion corresponding to the opening, the laminated material was ruled using a punching die and punched to obtain a blank plate. Were heat-welded to form a sleeve, and the sleeve was used in a molding and filling machine to produce a 500 ml internal capacity container with a capacity of 500 ml.

The paper containers prepared in Examples 1 to 15 and Comparative Examples 1 to 4 were filled with 500 ml of orange juice as the contents while being heat-sterilized by a hot filling method at about 80 ° C., sealed, and stored at 25 ° C. for 1 month. Thereafter, the opening at the top of the govel top was opened, and the sensory evaluation was performed as follows for the unsealing property, flavor retention, and oxidative degradation inhibiting effect.
(1) Opening property A case where there was no delamination that could be placed on the co-extruded portion and it could be easily opened was designated as ◯, and a case where it was not.
(2) Flavor retention The odor of the head space was smelled when opened, and the case where no odor other than the scent of orange juice was observed was evaluated as ◯, and the case where the odor other than the scent of orange juice was observed was evaluated as x.
(3) Oxidative degradation inhibitory effect The orange juice after opening was visually compared with the orange juice before filling, and the case where no color change was observed was marked with ◯, and the color change was marked with x.
Table 2 shows the evaluation results.

In all of the paper containers of Examples 1 to 15, the evaluation results of the opening property, the flavor retention property, and the oxidation deterioration suppressing effect are all “◯”, and the paper container of each of Examples 1 to 15 is excellent in all of the opening property, the flavor retention property, and the oxidation deterioration suppressing effect. It was.

Although the paper container of Comparative Example 1 was excellent in openability and flavor retention, the orange juice was changed to brown and was inferior in terms of the effect of suppressing oxidation deterioration. The polyamide resin 12 used in the paper container of Comparative Example 1 is considered to have oxygen barrier performance but no oxygen absorption performance, and orange juice was oxidized and deteriorated.
Although the paper container of Comparative Example 2 was excellent in flavor retention and oxidative deterioration suppression effect, when the fusing part of the govel top part was peeled off and opened, the polyamide resin layer could be broken and opened cleanly. It was not possible and was inferior in terms of openability. It is considered that although the polyamide resin 12 and the transition metal compound (cobalt stearate (II)) coexisted, the oxygen absorption performance was expressed, but at the same time, the polyamide resin 12 was oxidatively decomposed and the polyamide resin layer was deteriorated in strength.
Although the paper container of Comparative Example 3 was excellent in the opening property and the oxidative deterioration suppressing effect, a strange odor was observed at the time of opening, and the flavor retention was poor. Since the polyamide resin 13 has a high terminal amino group concentration and is substantially difficult to oxidize, the polyamide resin layer is not greatly deteriorated in strength, and the oxygen absorption performance is exhibited by the coexistence of maleic acid-modified polybutadiene and cobalt stearate. However, it is considered that a bad odor was generated due to the generation of low molecular weight compounds accompanying the oxidative degradation of polybutadiene.
Although the paper container of Comparative Example 4 was excellent in the openability and the effect of suppressing oxidative deterioration, an iron odor was observed at the time of opening. Although the polyamide resin layer expresses oxygen barrier performance and the oxygen absorbent-containing LDPE expresses oxygen absorption performance, because iron powder is used as the oxygen absorbent, an iron odor caused by the iron powder has occurred. Conceivable.

The laminated material of the present invention and the paper container of the present invention formed by boxing the laminated material can be suitably used as a packaging material.

Claims

A paper base layer;
A laminated material comprising a layer containing a polyamide resin,
The polyamide resin is
An aromatic diamine unit represented by the following general formula (I-1), an alicyclic diamine unit represented by the following general formula (I-2), and a straight chain represented by the following general formula (I-3) 25 to 50 mol% of diamine units containing a total of 50 mol% or more of at least one diamine unit selected from the group consisting of aliphatic diamine units;
A dicarboxylic acid unit containing a total of 50 mol% or more of a linear aliphatic dicarboxylic acid unit represented by the following general formula (II-1) and / or an aromatic dicarboxylic acid unit represented by the following general formula (II-2) 25 to 50 mol%,
A laminated material containing 0.1 to 50 mol% of a structural unit represented by the following general formula (III).

[In the general formula (I-3), m represents an integer of 2 to 18. In the general formula (II-1), n represents an integer of 2 to 18. In the general formula (II-2), Ar represents an arylene group. In the general formula (III), R represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. ]
The laminate material according to claim 1, wherein R in the general formula (III) is a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms.
The laminate material according to claim 1 or 2, 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 laminated material in any one of.
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 total of 50 mol% or more. The laminated material of crab.
6. The polyamide resin according to claim 1, further comprising 0.1 to 49.9 mol% of ω-aminocarboxylic acid units represented by the following general formula (X) in all structural units of the polyamide resin. The laminated material of crab.

[In the general formula (X), p represents an integer of 2 to 18. ]
The laminate according to claim 6, wherein the ω-aminocarboxylic acid unit contains a total of 50 mol% or more of 6-aminohexanoic acid units and / or 12-aminododecanoic acid units.
The laminate material according to any one of claims 1 to 7, wherein the polyamide resin has a relative viscosity of 1.8 to 4.2.
A paper container formed by box-producing the laminated material according to any one of claims 1 to 8.