JP5962426B2 - Preservation method of liquid tea or pasty tea - Google Patents

Description

The present invention relates to a method for preserving liquid tea or pasty tea for a long period of time while preventing deterioration due to oxidation and maintaining good flavor and color tone.

  Natural tea is a healthy nutritional food that is rich in vitamins and fiber and has been used in the diet. In addition, the scent and flavor of natural tea ingredients are generally preferred, and natural teas having such characteristics are not only used as tea beverages after being treated with hot water as they are, but also for example in teas such as mousse and ice cream. It is also used in processed foods that take advantage of its characteristics.

Natural tea having such characteristics easily changes in quality due to the influence of moisture and oxidation, and deterioration of tea color, flavor, aroma and the like occurs. Deterioration is caused by the effect of moisture and oxygen on dried tea, and when natural tea is treated with hot water and stored as a tea beverage or concentrated tea liquid, natural green tea is ground into powder and moisture and fats and oils It occurs even when it is mixed into a paste and used in processed foods. When storing liquid beverage tea or concentrated tea liquid, oxidative degradation of chlorophyll, catechinic acid, vitamin C, and unsaturated fatty acids may occur due to the effect of dissolved oxygen in the liquid, resulting in discoloration, fragrance, and reduced flavor. . For this reason, when storing beverage tea and concentrated tea liquid, it is necessary to consider the addition of a large amount of vitamin C, the storage temperature, and the like. In addition, when preserving pasty tea used for processed foods, etc., there is disclosed a method of preserving heat by avoiding contact with oxygen as much as possible by mixing powdered green tea and liquid oil (patent) Reference 1). However, even with this method, the discoloration of tea cannot be suppressed due to the influence of oxygen such as bubbles that are generated during mixing and dissolved oxygen in the added water, and it is necessary to control the generation of bubbles and the amount of water added during the manufacturing process. Had the problem that the flavor was lowered by oxidation of the added fats and oils.

  In addition, there is a technology for filling and storing liquid tea or pasty tea in glass bottles, but glass bottles are used for barrier bags, barrier trays, etc. due to the problem of non-combustible waste disposal and the need for lighter packaging containers. Is being transferred to plastic containers. However, when liquid tea or pasty tea is stored in a normal container such as a barrier bag, no matter how the gas replacement operation is performed, it is filled with trace oxygen remaining in the packaging container or liquid tea or pasty tea. It is unavoidable that the flavor or browning of liquid tea or pasty tea is caused by the trace amount of oxygen dissolved in the liquid.

  On the other hand, a deoxygenation packaging technique is known as a method for improving food storage stability and preventing flavor deterioration. In recent years, as one of the deoxygenation packaging technologies, a container is constituted by a multilayer material in which an oxygen absorption layer composed of an oxygen absorption resin composition in which an iron-based oxygen absorber is blended with a thermoplastic resin, and the gas barrier property of the container is increased. Development of a packaging container in which an oxygen absorbing function is imparted to the container itself is being promoted. For example, an oxygen-absorbing multilayer film is a thermoplastic in which an oxygen absorbent is dispersed between a conventional gas-barrier multilayer film in which a heat seal layer and a gas barrier layer are laminated, and optionally through an intermediate layer made of a thermoplastic resin. It is used as a resin layer with an oxygen absorption layer added to the outside to prevent oxygen permeation, and to absorb oxygen in the container. It is manufactured using a method (see Patent Document 2).

  However, those using an oxygen absorbent such as iron powder have a problem that internal visibility is insufficient due to the problem of opacity, which is detected by a metal detector used for detecting foreign substances such as food.

  On the other hand, an oxygen-absorbing resin composition comprising a resin and a transition metal catalyst and having oxygen scavenging properties is known. For example, a resin composition comprising a polyamide, particularly a xylylene group-containing polyamide and a transition metal catalyst, is known as an oxidizable organic component, and further a resin composition having an oxygen scavenging function and oxygen obtained by molding the resin composition There are also examples of absorbents, packaging materials, and multilayer laminated films for packaging (see Patent Document 3).

  Further, as an oxygen-absorbing resin composition that does not require moisture for oxygen absorption, an oxygen-absorbing resin composition comprising a resin having a carbon-carbon unsaturated bond and a transition metal catalyst is known (see Patent Document 4).

  Furthermore, as a composition for collecting oxygen, a composition comprising a polymer containing a substituted cyclohexene functional group or a low molecular weight substance bonded with the cyclohexene ring and a transition metal is known (see Patent Document 5).

JP-A-7-79702 Japanese Patent Laid-Open No. 9-234832 JP 2001-252560 A Japanese Patent Laid-Open No. 05-115776 Special table 2003-521552 gazette

However, since the resin composition of Patent Document 3 expresses an oxygen absorption function by containing a transition metal catalyst and oxidizing a xylylene group-containing polyamide resin, strength reduction due to oxidative degradation of the resin occurs, and packaging There is a problem that the strength of the container itself is lowered. Furthermore, this resin composition still has a problem that oxygen absorption performance is insufficient.

In addition, the oxygen-absorbing resin composition of Patent Document 4 has a problem in that a low molecular weight organic compound that becomes an odor component is generated by the cleavage of a polymer chain accompanying oxidation of the resin, and the strength of the odor increases after oxygen absorption. .

Furthermore, the composition of Patent Document 5 requires the use of a special material containing a cyclohexene functional group, and this material has a problem that it is relatively easy to generate an odor.

  The object of the present invention has been made in view of the above problems, and the object thereof is to provide a method for storing liquid tea or pasty tea stably and without reducing flavor and color. is there.

  As a result of studying a method for preserving liquid tea or pasty tea, the present inventors have used liquid tea or pasty tea as a container for an oxygen-absorbing resin composition comprising a polyester compound having a tetralin ring and a transition metal catalyst. The present invention has been completed by finding that the above-mentioned problems can be solved by storing in a container used in one layer.

That is, the present invention provides the following <1> to <4>.
<1> Liquid tea or pasty tea, an oxygen-absorbing layer (layer A) comprising an oxygen-absorbing resin composition containing a polyester compound and a transition metal catalyst, and a resin layer (layer B) containing a thermoplastic resin A method for preserving liquid tea or pasty tea that is preserved in an oxygen-absorbing container using all or part of the oxygen-absorbing multilayer body comprising
The polyester compound is represented by the following general formulas (1) to (4).

(In the formula, each R independently represents a hydrogen atom or a monovalent substituent, and the monovalent substituent is a halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, cyano group, A group consisting of a group, a hydroxy group, a carboxyl group, an ester group, an amide group, a nitro group, an alkoxy group, an aryloxy group, an acyl group, an amino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, and an imide group At least one selected from the above, which may further have a substituent, m represents an integer of 0 to 3, n represents an integer of 0 to 7, and at least one hydrogen atom at the benzyl position of the tetralin ring. X is an aromatic hydrocarbon group, a saturated or unsaturated alicyclic hydrocarbon group, a linear or branched saturated or unsaturated aliphatic hydrocarbon group, and a heterocyclic ring. It represents a divalent group containing at least one group selected from the group consisting of.)
Containing a structural unit having at least one tetralin ring selected from the group consisting of:
A method for preserving liquid tea or pasty tea.
<2> Preservation of liquid tea or pasty tea according to the above <1>, wherein the transition metal catalyst contains at least one transition metal selected from the group consisting of manganese, iron, cobalt, nickel and copper. Method.
<3> The liquid tea or pasty tea according to <1> or <2>, wherein the transition metal catalyst is contained in an amount of 0.001 to 10 parts by mass as a transition metal amount with respect to 100 parts by mass of the polyester compound. Preservation method.
<4> Any of the above <1> to <3>, wherein the structural unit represented by the general formula (1) is at least one selected from the group consisting of the following formulas (5) to (7): The method for preserving liquid tea or pasty tea according to 1.

  ADVANTAGE OF THE INVENTION By this invention, the method which can preserve | save liquid tea or pasty tea for a long period of time without impairing the flavor of liquid tea or pasty tea, and generating no odor can be provided. In addition, it can replace metal cans and glass bottles, making it possible to reduce the weight of containers and reduce waste and incombustibles. In addition, the packaging container retains strength even after long-term storage.

  Embodiments of the present invention will be described below. In addition, the following embodiment is an illustration for demonstrating this invention, and this invention is not limited only to the embodiment.

[tea]
The tea used in the present invention is non-fermented tea (green tea), semi-fermented tea or fermented tea. Non-fermented teas are roasted tea obtained by roasting green teas and green teas such as gyokuro, matcha, sencha, bancha, tencha, and tamago green tea, oolong teas and baked tea as semi-fermented teas, and black tea as fermented teas Is mentioned. In the present invention, the liquid tea refers to a liquid beverage tea obtained by extracting these teas as they are or after being ground into a powder and then extracting with hot water, and a concentrated tea liquid obtained by a method such as vacuum concentration of the beverage tea. . The pasty tea refers to a mixture of powdered tea obtained by grinding tea with oil and / or water.

Here, the fats and oils are not particularly limited, but for example, vegetable oils and fats such as cottonseed oil, sesame oil, olive oil, coconut oil, palm oil, corn oil, soybean oil, rapeseed oil, sunflower oil, coconut oil and the like Two or more kinds of mixed oils selected from the above are preferable in that they are liquid at room temperature and can be easily mixed with powdered tea. Moreover, in order not to impair the color, flavor and aroma of tea, the fats and oils are preferably tasteless, odorless and colorless. Moreover, when obtaining pasty tea, you may mix an emulsifier suitably. By mixing the emulsifier, a water-soluble pasty tea can be obtained and used for processed foods such as soft cream. Further, a seasoning such as a sweetener may be appropriately added in advance according to the use.

These liquid beverage tea, concentrated tea and pasty tea may be subjected to heat treatment. For the temperature and heating time of the heat treatment, for example, conditions under which the coliform bacteria can be killed are set, and other conditions under which general viable bacteria can be killed are set. Furthermore, you may add nutrients, such as ascorbic acid, suitably.

  Hereinafter, embodiments of the oxygen-absorbing multilayer body used in the method for preserving liquid tea or pasty tea of the present invention will be described.

[Oxygen-absorbing multilayer]
The oxygen-absorbing multilayer body of this embodiment includes at least an oxygen-absorbing layer (layer A) made of an oxygen-absorbing resin composition and a resin layer (layer B) containing a thermoplastic resin.

  The layer configuration in the oxygen-absorbing multilayer body of the present embodiment is not particularly limited, and the number and type of layers A and B are not particularly limited. For example, it may be an A / B configuration consisting of one layer A and one layer B, or a three-layer configuration B / A / B consisting of one layer A and two layers B. Also good. Further, a five-layer configuration of B1 / B2 / A / B2 / B1 composed of one layer A and two types and four layers B of layers B1 and B2 may be used. Furthermore, the multilayer body of the present embodiment may include an arbitrary layer such as an adhesive layer (layer AD) as necessary. For example, the multilayer body has a seven-layer configuration of B1 / AD / B2 / A / B2 / AD / B1. There may be.

[Oxygen absorbing layer (layer A)]
The oxygen absorption layer (layer A) of this embodiment comprises a polyester compound and a transition metal catalyst containing a structural unit having at least one tetralin ring selected from the group consisting of the above general formulas (1) to (4). It consists of an oxygen-absorbing resin composition.

  The content of the polyester compound in the layer A is preferably 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 90% by mass or more. In the case of the said range, compared with the case where it is less than 50 mass%, oxygen absorption performance can be improved more.

[Polyester compound]
The polyester compound of this embodiment contains the structural unit which has at least 1 type of tetralin ring represented by either of the said general formula (1)-(4).

  In the general formulas (1) to (4) and (8) to (15) of the present application, examples of the monovalent substituent represented by R include a halogen atom (for example, a chlorine atom, a bromine atom, an iodine atom), and an alkyl group. (Preferably a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, more preferably 1 to 6 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, t- A butyl group, an n-octyl group, a 2-ethylhexyl group, a cyclopropyl group, a cyclopentyl group), an alkenyl group (preferably having 2 to 10 carbon atoms, more preferably 2 to 6 linear, branched or branched) Cyclic alkenyl groups such as vinyl and allyl groups, alkynyl groups (preferably alkynyl groups having 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms such as ethynyl groups and propargyl groups), Group (preferably an aryl group having 6 to 16 carbon atoms, more preferably an aryl group having 6 to 10 carbon atoms, such as a phenyl group or a naphthyl group), a heterocyclic group (preferably having a carbon number of 1 to 12, more preferably A monovalent group obtained by removing one hydrogen atom from a 5-membered or 6-membered aromatic or non-aromatic heterocyclic compound having 2 to 6 carbon atoms, such as a 1-pyrazolyl group, 1 -Imidazolyl group, 2-furyl group), cyano group, hydroxy group, carboxyl group, ester group, amide group, nitro group, alkoxy group (preferably having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms). A linear, branched or cyclic alkoxy group such as a methoxy group or an ethoxy group, an aryloxy group (preferably an aryloxy group having 6 to 12 carbon atoms, more preferably 6 to 8 carbon atoms, eg A phenoxy group), an acyl group (including a formyl group, preferably an alkylcarbonyl group having 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, preferably 7 to 12 carbon atoms, more preferably carbon. An arylcarbonyl group having 7 to 9 carbon atoms, for example, an acetyl group, a pivaloyl group, a benzoyl group), an amino group (preferably having 1 to 10 carbon atoms, more preferably an alkylamino group having 1 to 6 carbon atoms, preferably An anilino group having 6 to 12 carbon atoms, more preferably 6 to 8 carbon atoms, preferably a heterocyclic amino group having 1 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, such as an amino group, methyl Amino group, anilino group), mercapto group, alkylthio group (preferably an alkylthio group having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, such as methylthio group, ethyl Luthio group), an arylthio group (preferably an arylthio group having 6 to 12 carbon atoms, more preferably an arylthio group having 6 to 8 carbon atoms, such as a phenylthio group), a heterocyclic thio group (preferably having 2 to 10 carbon atoms, and more). Preferably a heterocyclic thio group having 1 to 6 carbon atoms, such as a 2-benzothiazolylthio group, an imide group (preferably an imide group having 2 to 10 carbon atoms, more preferably 4 to 8 carbon atoms, Examples thereof include N-succinimide group and N-phthalimide group), but are not particularly limited thereto.

  In addition, when said monovalent substituent R has a hydrogen atom, the hydrogen atom is a substituent T (Here, the substituent T is synonymous with what was demonstrated by said monovalent substituent R.). ) May be further substituted. Specific examples thereof include, for example, an alkyl group substituted with a hydroxy group (for example, hydroxyethyl group), an alkyl group substituted with an alkoxy group (for example, methoxyethyl group), and an alkyl group substituted with an aryl group (for example, Benzyl group), alkyl groups substituted with primary or secondary amino groups (eg aminoethyl group), aryl groups substituted with alkyl groups (eg p-tolyl group), substituted with alkyl groups Aryloxy groups (for example, 2-methylphenoxy group) and the like, but are not particularly limited thereto. When the monovalent substituent R has a monovalent substituent T, the carbon number described above does not include the carbon number of the substituent T. 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. When the monovalent substituent R has a substituent T, there may be a plurality of the substituents T.

  X is at least one selected from the group consisting of an aromatic hydrocarbon group, a saturated or unsaturated alicyclic hydrocarbon group, a linear or branched saturated or unsaturated aliphatic hydrocarbon group, and a heterocyclic group. Represents a divalent group containing one group. The aromatic hydrocarbon group, saturated or unsaturated alicyclic hydrocarbon group, linear or branched saturated or unsaturated aliphatic hydrocarbon group and heterocyclic group may be substituted or unsubstituted. . X may contain a hetero atom, and may contain an ether group, sulfide group, carbonyl group, hydroxy group, amino group, sulfoxide group, sulfone group, and the like. Here, as the aromatic hydrocarbon group, for example, o-phenylene group, m-phenylene group, p-phenylene group, methylphenylene group, o-xylylene group, m-xylylene group, p-xylylene group, naphthylene group, Anthracenylene group, phenanthrylene group, biphenylene group, fluoronylene group and the like can be mentioned, but not limited thereto. Examples of the alicyclic hydrocarbon group include a cycloalkylene group such as a cyclopentylene group, a cyclohexylene group, a methylcyclohexylene group, a cycloheptylene group, and a cyclooctylene group, and a cycloalkenylene group such as a cyclohexenylene group. Although it is mentioned, it is not specifically limited to these. Examples of the aliphatic hydrocarbon group include methylene group, ethylene group, trimethylene group, propylene group, isopropylidene group, tetramethylene group, isobutylene group, tert-butylene group, pentamethylene group, hexamethylene group, heptamethylene group, Linear or branched alkylene groups such as octamethylene group, nonamethylene group, decamethylene group, vinylene group, propenylene group, 1-butenylene group, 2-butenylene group, 1,3-butadienylene group, 1-pentenylene group Alkenylene groups such as 2-pentenylene group, 1-hexenylene group, 2-hexenylene group, 3-hexenylene group and the like, but are not particularly limited thereto. These may further have a substituent, and specific examples thereof include, for example, halogen, alkoxy group, hydroxy group, carboxyl group, carboalkoxy group, amino group, acyl group, thio group (for example, alkylthio group, Phenylthio group, tolylthio group, pyridylthio group, etc.), amino group (for example, unsubstituted amino group, methylamino group, dimethylamino group, phenylamino group, etc.), cyano group, nitro group and the like, but not limited thereto .

  The polyester compound containing the structural unit represented by the general formula (1) can be obtained by polycondensation of a dicarboxylic acid having a tetralin ring or a derivative (I) thereof and a diol or a derivative (II) thereof.

The dicarboxylic acid having a tetralin ring or its derivative (I) used in the present embodiment is represented by the following general formula (8). These can be used alone or in combination of two or more.

(In the formula, each R independently represents a hydrogen atom or a monovalent substituent, and the monovalent substituent is a halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, cyano group, A group consisting of a group, a hydroxy group, a carboxyl group, an ester group, an amide group, a nitro group, an alkoxy group, an aryloxy group, an acyl group, an amino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, and an imide group At least one selected from the above, which may further have a substituent, m represents an integer of 0 to 3, n represents an integer of 0 to 7, and at least one hydrogen atom at the benzyl position of the tetralin ring. Atoms are bonded. Y represents a hydrogen atom or an alkyl group.)

The compound represented by the general formula (8) can be obtained by reacting a dicarboxylic acid having a naphthalene ring represented by the following general formula (9) or a derivative thereof with hydrogen.

(In the formula, each R independently represents a hydrogen atom or a monovalent substituent, and the monovalent substituent is a halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, cyano group, A group consisting of a group, a hydroxy group, a carboxyl group, an ester group, an amide group, a nitro group, an alkoxy group, an aryloxy group, an acyl group, an amino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, and an imide group These are at least one selected, and may further have a substituent, each m independently represents an integer of 0 to 3, and Y represents a hydrogen atom or an alkyl group.)

  Examples of the diol or derivative (II) used in the present embodiment include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-propanediol, 2-methyl- 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1 , 9-nonanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, 2-phenylpropanediol, 2- (4-hydroxyphenyl) ethyl alcohol, α, α-dihydroxy-1,3-diisopropylbenzene, α, α Dihydroxy-1,4-diisopropylbenzene, o- xylene glycol, m- xylene glycol, p- xylene glycol, hydroquinone, 4,4-dihydroxyphenyl, naphthalene diol or derivatives thereof,. These can be used alone or in combination of two or more.

  The polyester compound containing the structural unit represented by the general formula (2) is obtained by polycondensation of a diol having a tetralin ring or a derivative (III) thereof and a dicarboxylic acid or a derivative (IV) thereof. It is done.

A diol having a tetralin ring or a derivative (III) thereof used in the present embodiment is represented by the following general formula (10). These can be used alone or in combination of two or more.

(In the formula, each independently represents a hydrogen atom or a monovalent substituent, and the monovalent substituent is a halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, cyano group, hydroxy group, Selected from the group consisting of a group, carboxyl group, ester group, amide group, nitro group, alkoxy group, aryloxy group, acyl group, amino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group and imide group At least one kind, which may further have a substituent, m represents an integer of 0 to 3, n represents an integer of 0 to 7, and at least one hydrogen atom is bonded to the benzyl position of the tetralin ring. doing.)

The compound represented by the general formula (10) can be obtained by reacting a diol having a naphthalene ring represented by the following general formula (11) or a derivative thereof with hydrogen.

(In the formula, each R independently represents a hydrogen atom or a monovalent substituent, and the monovalent substituent is a halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, cyano group, A group consisting of a group, a hydroxy group, a carboxyl group, an ester group, an amide group, a nitro group, an alkoxy group, an aryloxy group, an acyl group, an amino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, and an imide group These are at least one selected, and may further have a substituent, each m independently represents an integer of 0 to 3.)

  Examples of the dicarboxylic acid or derivative (IV) used in the present embodiment include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid. Benzenedicarboxylic acid such as 3,3-dimethylpentanedioic acid, phthalic acid, isophthalic acid and terephthalic acid, naphthalenedicarboxylic acid such as 2,6-naphthalenedicarboxylic acid, anthracene dicarboxylic acid, phenylmalonic acid, phenylenediacetic acid, pheny Examples include dibutyric acid, 4,4-diphenyl ether dicarboxylic acid, p-phenylene dicarboxylic acid, and derivatives thereof. These can be used alone or in combination of two or more.

  The polyester compound containing the structural unit represented by the general formula (3) or (4) can be obtained by polycondensation of a hydroxycarboxylic acid having a tetralin ring or a derivative (V) thereof.

The hydroxycarboxylic acid having a tetralin ring or its derivative (V) used in the present embodiment is represented by the following general formula (12) or (13). These can be used alone or in combination of two or more.

(In the formula, each R independently represents a hydrogen atom or a monovalent substituent, and the monovalent substituent is a halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, cyano group, A group consisting of a group, a hydroxy group, a carboxyl group, an ester group, an amide group, a nitro group, an alkoxy group, an aryloxy group, an acyl group, an amino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, and an imide group At least one selected from the above, which may further have a substituent, m represents an integer of 0 to 3, n represents an integer of 0 to 7, and at least one hydrogen atom at the benzyl position of the tetralin ring. Atoms are bonded. Y represents a hydrogen atom or an alkyl group.)

The polyester compound containing the structural unit represented by the general formula (1) or (2) is obtained by hydrogenation reaction of the polyester compound containing the structural unit represented by the following general formula (14) or (15). You can also

(In the formula, each R independently represents a hydrogen atom or a monovalent substituent, and the monovalent substituent is a halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, cyano group, A group consisting of a group, a hydroxy group, a carboxyl group, an ester group, an amide group, a nitro group, an alkoxy group, an aryloxy group, an acyl group, an amino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, and an imide group At least one selected from the above, which may further have a substituent, each m independently represents an integer of 0 to 3. X is an aromatic hydrocarbon group, a saturated or unsaturated fat. Represents a divalent group containing at least one group selected from the group consisting of a cyclic hydrocarbon group, a linear or branched saturated or unsaturated aliphatic hydrocarbon group and a heterocyclic group. )

(In the formula, each R independently represents a hydrogen atom or a monovalent substituent, and the monovalent substituent is a halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, cyano group, A group consisting of a group, a hydroxy group, a carboxyl group, an ester group, an amide group, a nitro group, an alkoxy group, an aryloxy group, an acyl group, an amino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, and an imide group At least one selected from the above, which may further have a substituent, each m independently represents an integer of 0 to 3. X is an aromatic hydrocarbon group, a saturated or unsaturated fat. Represents a divalent group containing at least one group selected from the group consisting of a cyclic hydrocarbon group, a linear or branched saturated or unsaturated aliphatic hydrocarbon group and a heterocyclic group. )

  In the polyester compound of the present embodiment, a constitutional unit having no tetralin ring may be incorporated as a copolymer component to the extent that it does not affect the performance. Specifically, the diol or its derivative (II) or the compound shown in the dicarboxylic acid or its derivative (IV) can be used as a copolymerization component.

Preferred specific examples of the polyester compound containing the structural unit represented by the general formula (1) include the above formulas (5) to (7) and the following formulas (16) to (18). It is not limited to.

  All of the above-mentioned polyester compounds have hydrogen at the benzylic position of the tetralin ring, and when used in combination with the above-described transition metal catalyst, the hydrogen at the benzylic position is extracted, thereby exhibiting excellent oxygen absorption capacity. .

  Moreover, the oxygen-absorbing resin composition of the present embodiment is one in which odor generation after oxygen absorption is suppressed. Although the reason is not clear, for example, the following oxidation reaction mechanism is assumed. That is, in the polyester compound, first, hydrogen at the benzylic position of the tetralin ring is extracted to generate a radical, and then the benzylic carbon is oxidized by the reaction between the radical and oxygen to generate a hydroxy group or a ketone group. Conceivable. Therefore, in the oxygen-absorbing resin composition of the present embodiment, the molecular chain of the oxygen-absorbing main agent is not broken by the oxidation reaction as in the prior art, and the structure of the polyester compound is maintained, which causes odor. It is presumed that low molecular weight organic compounds are not easily formed after oxygen absorption, and as a result, increase in odor intensity after oxygen absorption is suppressed.

  The intrinsic viscosity of the polyester compound of the present embodiment (measured value at 25 ° C. using a mixed solvent of phenol and 1,1,2,2-tetrachloroethane in a mass ratio of 6: 4) is not particularly limited. From the viewpoint of moldability, 0.1 to 2.0 dL / g is preferable, and 0.5 to 1.5 dL / g is more preferable.

  The transition metal catalyst used in the oxygen-absorbing resin composition of the present embodiment can be appropriately selected from known ones as long as it can function as a catalyst for the oxidation reaction of the polyester compound, There is no particular limitation.

  Specific examples of the transition metal catalyst include, for example, organic acid salts, halides, phosphates, phosphites, hypophosphites, nitrates, sulfates, oxides and hydroxides of transition metals. Here, examples of the transition metal contained in the transition metal catalyst include, but are not limited to, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, ruthenium, and rhodium. Among these, manganese, iron, cobalt, nickel, and copper are preferable. Examples of organic acids include acetic acid, propionic acid, octanoic acid, lauric acid, stearic acid, acetylacetone, dimethyldithiocarbamic acid, palmitic acid, 2-ethylhexanoic acid, neodecanoic acid, linoleic acid, toluic acid, oleic acid, Although capric acid and naphthenic acid are mentioned, it is not limited to these. The transition metal catalyst is preferably a combination of these transition metals and an organic acid, the transition metal is manganese, iron, cobalt, nickel or copper, and the organic acid is acetic acid, stearic acid, 2-ethylhexanoic acid, olein. A combination that is an acid or naphthenic acid is more preferred. In addition, a transition metal catalyst can be used individually by 1 type or in combination of 2 or more types.

  The compounding quantity of a transition metal catalyst can be suitably set according to the kind and desired performance of the said polyester compound and transition metal catalyst to be used, and is not specifically limited. From the viewpoint of the oxygen absorption amount of the oxygen-absorbing resin composition, the blending amount of the transition metal catalyst is preferably 0.001 to 10 parts by mass as the transition metal amount, more preferably 100 parts by mass of the polyester compound. Is 0.002 to 2 parts by mass, more preferably 0.005 to 1 part by mass.

  The polyester compound and the transition metal catalyst can be mixed by a known method, but can be used as an oxygen-absorbing resin composition having good dispersibility, preferably by kneading with an extruder. Further, in the oxygen-absorbing resin composition, additives such as a desiccant, a pigment, a dye, an antioxidant, a slip agent, an antistatic agent, a stabilizer, etc., calcium carbonate, A filler such as clay, mica, and silica, a deodorant, and the like may be added, but various materials can be mixed without being limited to the above-described ones.

  Note that the oxygen-absorbing resin composition of the present embodiment may further contain a radical generator or a photoinitiator as necessary in order to promote the oxygen absorption reaction. Specific examples of the radical generator include various N-hydroxyimide compounds such as N-hydroxysuccinimide, N-hydroxymaleimide, N, N′-dihydroxycyclohexanetetracarboxylic acid diimide, N-hydroxyphthalimide, N-hydroxytetrachlorophthalimide, N-hydroxytetrabromophthalimide, N-hydroxyhexahydrophthalimide, 3-sulfonyl-N-hydroxyphthalimide, 3-methoxycarbonyl-N-hydroxyphthalimide, 3-methyl-N-hydroxyphthalimide, 3 -Hydroxy-N-hydroxyphthalimide, 4-nitro-N-hydroxyphthalimide, 4-chloro-N-hydroxyphthalimide, 4-methoxy-N-hydroxyphthalimide, 4-dimethylamino -N-hydroxyphthalimide, 4-carboxy-N-hydroxyhexahydrophthalimide, 4-methyl-N-hydroxyhexahydrophthalimide, N-hydroxyhetic acid imide, N-hydroxyhymic acid imide, N-hydroxytrimellitic acid imide , N, N-dihydroxypyromellitic acid diimide and the like, but are not particularly limited thereto. Specific examples of the photoinitiator include, but are not limited to, benzophenone and its derivatives, thiazine dyes, metal porphyrin derivatives, anthraquinone derivatives, and the like. In addition, these radical generators and photoinitiators can be used individually by 1 type or in combination of 2 or more types.

  In addition, the oxygen-absorbing resin composition of the present embodiment can be kneaded with another thermoplastic resin and an extruder as long as the purpose of the present embodiment is not impaired. Examples of the thermoplastic resin used for kneading include low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, linear ultra low density polyethylene, polypropylene, poly-1-butene, and poly-4-methyl. -1-pentene, polyolefins such as random or block copolymers of α-olefins such as ethylene, propylene, 1-butene, 4-methyl-1-pentene, maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, etc. Acid-modified polyolefin, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-vinyl chloride copolymer, ethylene- (meth) acrylic acid copolymer and its ionic cross-linked product (ionomer), ethylene- Methyl methacrylate copolymer, etc. Styrene resins such as ethylene-vinyl compound copolymers, polystyrene, acrylonitrile-styrene copolymers, α-methylstyrene-styrene copolymers, polyvinyl compounds such as polymethyl acrylate and polymethyl methacrylate, nylon 6, nylon 66, nylon 610, nylon 12, polyamide such as polymetaxylylene adipamide (MXD6), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), glycol Modified polyethylene terephthalate (PETG), polyethylene succinate (PES), polybutylene succinate (PBS), polylactic acid, polyglycolic acid, polycaprolactone, polyhydroxyalkano Polyester over preparative like, polycarbonate, polyether, or mixtures thereof, such as polyethylene oxide.

  Although there is no restriction | limiting in particular in the thickness of an oxygen absorption layer (layer A), 1-1000 micrometers is preferable, More preferably, it is 2-800 micrometers, More preferably, it is 5-700 micrometers. In this case, compared with the case where the thickness is out of the above range, the ability of the layer A to absorb oxygen can be further enhanced, and economic efficiency can be prevented from being impaired.

[Resin layer containing thermoplastic resin (layer B)]
The layer B of this embodiment is a layer containing a thermoplastic resin. The content of the thermoplastic resin in the layer B is not particularly limited, but the content of the thermoplastic resin relative to the total amount of the layer B is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, and 90 to 90%. 100% by mass is particularly preferred.

  The oxygen-absorbing multilayer body of this embodiment may have a plurality of layers B, and the configurations of the plurality of layers B may be the same or different from each other. The thickness of the layer B can be appropriately determined according to the use, and from the viewpoint of securing various physical properties such as strength and flexibility required for the multilayer body, preferably from 5 to 1000 μm, more Preferably it is 10-800 micrometers, More preferably, it is 20-500 micrometers.

  Arbitrary thermoplastic resins can be used for the thermoplastic resin of this embodiment, and it is not specifically limited. Examples thereof include polyolefins, polyesters, polyamides, ethylene-vinyl alcohol copolymers, plant-derived resins, and chlorinated resins. In the present embodiment, the thermoplastic resin preferably includes at least one selected from the group consisting of these resins. Moreover, in the said thermoplastic resin, it is preferable that content of thermoplastic resins other than the said polyester compound of this invention is 50-100 mass%, 70-100 mass% is more preferable, 90-100 mass% Is particularly preferred.

[Polyolefin]
Specific examples of polyolefin include low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, linear ultra low density polyethylene, and the like, such as polypropylene, polybutene-1, poly-4-methylpentene-1, and the like. Olefin homopolymer; ethylene-propylene random copolymer, ethylene-propylene block copolymer, ethylene-propylene-polybutene-1 copolymer, ethylene-cyclic olefin copolymer, etc. Copolymer of ethylene and α-olefin Copolymer; Ethylene-α, β-unsaturated carboxylic acid copolymer such as ethylene- (meth) acrylic acid copolymer, ethylene-α, β-unsaturated carboxylic acid such as ethylene- (meth) acrylic acid ethyl copolymer Acid ester copolymer, ionic cross-linked product of ethylene-α, β-unsaturated carboxylic acid copolymer, Other ethylene copolymers such as tylene-vinyl acetate copolymers; ring-opening polymers of cyclic olefins and hydrogenated products thereof; cyclic olefins-ethylene copolymers; and these polyolefins with acid anhydrides such as maleic anhydride Examples thereof include graft-modified polyolefins graft-modified with products.

[polyester]
The polyester described here is a polyester that can be used as a thermoplastic resin, and is not a polyester compound of the present embodiment. In the present embodiment, the polyester is composed of one or more selected from polycarboxylic acids containing dicarboxylic acids and ester-forming derivatives thereof, and one or more selected from polyhydric alcohols containing glycol. Or those composed of hydroxycarboxylic acids and their ester-forming derivatives, or those composed of cyclic esters. The ethylene terephthalate-based thermoplastic polyester is composed of the ethylene terephthalate unit in the majority of ester repeating units, generally 70 mol% or more, and has a glass transition temperature (Tg) of 50 to 90 ° C. and a melting point (Tm) of 200 to 275. Those in the range of ° C. are preferred. Polyethylene terephthalate is particularly excellent as an ethylene terephthalate thermoplastic polyester in terms of pressure resistance, heat resistance, heat pressure resistance, etc. In addition to ethylene terephthalate units, dibasic acids such as isophthalic acid and naphthalenedicarboxylic acid and diols such as propylene glycol Copolyesters containing a small amount of ester units consisting of can also be used.

  Examples of dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, tetradecanedicarboxylic acid, hexadecanedicarboxylic acid, 3- Exemplified as cyclobutanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid, dimer acid, etc. Saturated aliphatic dicarboxylic acids or ester-forming derivatives thereof, unsaturated aliphatic dicarboxylic acids exemplified by fumaric acid, maleic acid, itaconic acid or the like, or ester-forming derivatives thereof, orthophthalic acid, isophthalic acid, terephthalic acid 1,3-na Taleenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, 4,4′- Aromatic dicarboxylic acids exemplified by biphenylsulfone dicarboxylic acid, 4,4′-biphenyl ether dicarboxylic acid, 1,2-bis (phenoxy) ethane-p, p′-dicarboxylic acid, anthracene dicarboxylic acid, etc. or ester formation thereof Metal, exemplified by 5-sodium sulfoisophthalic acid, 2-sodium sulfoterephthalic acid, 5-lithium sulfoisophthalic acid, 2-lithium sulfoterephthalic acid, 5-potassium sulfoisophthalic acid, 2-potassium sulfoterephthalic acid, etc. Sulfonate group-containing aromatic dicarboxylic acid or Such lower alkyl esters thereof derivative.

  Among the above dicarboxylic acids, the use of terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid is particularly preferable in terms of the physical properties of the resulting polyester, and other dicarboxylic acids may be copolymerized as necessary. .

  As polyvalent carboxylic acids other than these dicarboxylic acids, ethanetricarboxylic acid, propanetricarboxylic acid, butanetetracarboxylic acid, pyromellitic acid, trimellitic acid, trimesic acid, 3,4,3 ′, 4′-biphenyltetracarboxylic acid, And ester-forming derivatives thereof.

  As glycols, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4 -Butylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediethanol, 1,10-decamethylene glycol, 1,12-dodecanediol, polyethylene glycol, polytrimethyl Aliphatic glycols exemplified by tylene glycol and polytetramethylene glycol, hydroquinone, 4,4′-dihydroxybisphenol, 1,4-bis (β-hydroxyethoxy) benzene, 1,4-bis (β- Hydroxyethoxyphenyl) sulfone, bis (p-hydroxyphenyl) ether, bis (p-hydroxyphenyl) sulfone, bis (p-hydroxyphenyl) methane, 1,2-bis (p-hydroxyphenyl) ethane, bisphenol A, bisphenol Examples thereof include aromatic glycols exemplified by C, 2,5-naphthalenediol, glycols obtained by adding ethylene oxide to these glycols, and the like.

  Among the above glycols, it is particularly preferable to use ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, and 1,4-cyclohexanedimethanol as the main component. Examples of polyhydric alcohols other than these glycols include trimethylolmethane, trimethylolethane, trimethylolpropane, pentaerythritol, glycerol, hexanetriol, and the like. Examples of hydroxycarboxylic acids include lactic acid, citric acid, malic acid, tartaric acid, hydroxyacetic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid, 4-hydroxycyclohexanecarboxylic acid, or these And ester-forming derivatives thereof.

  Examples of the cyclic ester include ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glycolide, and lactide.

  Examples of ester-forming derivatives of polyvalent carboxylic acids and hydroxycarboxylic acids include these alkyl esters, acid chlorides, acid anhydrides and the like.

  The polyester used in this embodiment is preferably a polyester in which the main acid component is terephthalic acid or an ester-forming derivative thereof or naphthalenedicarboxylic acid or an ester-forming derivative thereof, and the main glycol component is alkylene glycol.

  The polyester in which the main acid component is terephthalic acid or an ester-forming derivative thereof is preferably a polyester containing 70 mol% or more of terephthalic acid or an ester-forming derivative thereof in total with respect to the total acid component. A polyester containing 80 mol% or more is preferable, and a polyester containing 90 mol% or more is more preferable. Similarly, the polyester in which the main acid component is naphthalenedicarboxylic acid or an ester-forming derivative thereof is also preferably a polyester containing 70 mol% or more of naphthalenedicarboxylic acid or an ester-forming derivative thereof, more preferably 80 Polyesters containing at least mol%, more preferably polyesters containing at least 90 mol%.

  Examples of the naphthalenedicarboxylic acid or ester-forming derivative thereof used in the present embodiment include 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and the like exemplified in the above dicarboxylic acids. 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, or ester-forming derivatives thereof are preferred.

  The polyester whose main glycol component is an alkylene glycol is preferably a polyester containing 70 mol% or more of the total amount of alkylene glycol with respect to all glycol components, more preferably a polyester containing 80 mol% or more, More preferably, it is a polyester containing 90 mol% or more. The alkylene glycol here may contain a substituent or an alicyclic structure in the molecular chain.

  The copolymer components other than the terephthalic acid / ethylene glycol are isophthalic acid, 2,6-naphthalenedicarboxylic acid, diethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, 1,2-propanediol, 1,3-propane. It is preferably at least one selected from the group consisting of diol and 2-methyl-1,3-propanediol in order to achieve both transparency and moldability, particularly isophthalic acid, diethylene glycol, neopentyl glycol, More preferably, it is at least one selected from the group consisting of 1,4-cyclohexanedimethanol.

  A preferred example of the polyester used in this embodiment is a polyester in which the main repeating unit is composed of ethylene terephthalate, more preferably a linear polyester containing 70 mol% or more of ethylene terephthalate units, and still more preferably an ethylene terephthalate unit. Is a linear polyester containing 80 mol% or more, and particularly preferred is a linear polyester containing 90 mol% or more of ethylene terephthalate units.

  Another preferred example of the polyester used in this embodiment is a polyester in which the main repeating unit is composed of ethylene-2,6-naphthalate, and more preferably 70 mol% or more of ethylene-2,6-naphthalate unit. A linear polyester containing 80 mol% or more of ethylene-2,6-naphthalate units, particularly preferably a linear polyester containing 90 mol% or more of ethylene-2,6-naphthalate units. Polyester.

  Other preferred examples of the polyester used in this embodiment include linear polyesters containing 70 mol% or more of propylene terephthalate units, linear polyesters containing 70 mol% or more of propylene naphthalate units, and 1,4-cyclohexanedimethylene. A linear polyester containing 70 mol% or more of terephthalate units, a linear polyester containing 70 mol% or more of butylene naphthalate units, or a linear polyester containing 70 mol% or more of butylene terephthalate units.

  In particular, the composition of the whole polyester is a combination of terephthalic acid / isophthalic acid // ethylene glycol, terephthalic acid // ethylene glycol / 1,4-cyclohexanedimethanol, and terephthalic acid // ethylene glycol / neopentyl glycol. This is preferable in order to satisfy both the moldability and the moldability. Needless to say, a small amount (5 mol% or less) of diethylene glycol produced by dimerization of ethylene glycol may be included in the esterification (transesterification) reaction or polycondensation reaction.

  Other preferred examples of the polyester used in this embodiment include polyglycolic acid obtained by polycondensation of glycolic acid or methyl glycolate or ring-opening polycondensation of glycolide. This polyglycolic acid may be copolymerized with other components such as lactide.

[polyamide]
The polyamide used in the present embodiment is a polyamide having a unit derived from a lactam or an aminocarboxylic acid as a main constituent unit, or an aliphatic having a unit derived from an aliphatic diamine and an aliphatic dicarboxylic acid as a main constituent unit. Polyamide, Partially aromatic polyamide whose main constituent unit is a unit derived from aliphatic diamine and aromatic dicarboxylic acid, Partially aromatic whose main constituent unit is a unit derived from aromatic diamine and aliphatic dicarboxylic acid Examples thereof include polyamide, and a monomer unit other than the main structural unit may be copolymerized as necessary.

  Examples of the lactam or aminocarboxylic acid include lactams such as ε-caprolactam and laurolactam, aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid, and aromatic aminocarboxylic acids such as para-aminomethylbenzoic acid. .

  As the aliphatic diamine, an aliphatic diamine having 2 to 12 carbon atoms or a functional derivative thereof can be used. Furthermore, an alicyclic diamine may be used. The aliphatic diamine may be a linear aliphatic diamine or a branched chain aliphatic diamine. Specific examples of such linear aliphatic diamines include ethylenediamine, 1-methylethylenediamine, 1,3-propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, Examples include aliphatic diamines such as nonamethylenediamine, decamethylenediamine, undecamethylenediamine, and dodecamethylenediamine. Specific examples of the alicyclic diamine include cyclohexanediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, and the like.

  Moreover, as said aliphatic dicarboxylic acid, linear aliphatic dicarboxylic acid and alicyclic dicarboxylic acid are preferable, and also linear aliphatic dicarboxylic acid which has a C4-C12 alkylene group is especially preferable. Examples of such linear aliphatic dicarboxylic acids include adipic acid, sebacic acid, malonic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, undecanoic acid, undecadioic acid, dodecanedioic acid, dimer Examples thereof include acids and functional derivatives thereof. Examples of the alicyclic dicarboxylic acid include alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid.

  Examples of the aromatic diamine include metaxylylenediamine, paraxylylenediamine, para-bis (2-aminoethyl) benzene, and the like.

  Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4′-dicarboxylic acid, diphenoxyethanedicarboxylic acid, and functional derivatives thereof. It is done.

  Specific polyamides include polyamide 4, polyamide 6, polyamide 10, polyamide 11, polyamide 12, polyamide 4, 6, polyamide 6, 6, polyamide 6, 10, polyamide 6T, polyamide 9T, polyamide 6IT, polymetaxylylene azide. Pamide (Polyamide MXD6), Isophthalic acid copolymer polymetaxylylene adipamide (Polyamide MXD6I), Polymetaxylylene sebamide (Polyamide MXD10), Polymetaxylylene decanamide (Polyamide MXD12), Poly 1,3-bis Examples include aminocyclohexane adipamide (polyamide BAC6) and polyparaxylylene sebacamide (polyamide PXD10). More preferable polyamides include polyamide 6, polyamide MXD6, and polyamide MXD6I.

  Further, as a copolymerization component of the polyamide, a polyether having at least one terminal amino group or a terminal carboxyl group and a number average molecular weight of 2000 to 20000, or an organic carboxylate of the polyether having the terminal amino group, or An amino salt of a polyether having a terminal carboxyl group can also be used. Specific examples include bis (aminopropyl) poly (ethylene oxide) (polyethylene glycol having a number average molecular weight of 2000 to 20000).

  The partially aromatic polyamide may contain a structural unit derived from a polybasic carboxylic acid having 3 or more bases such as trimellitic acid and pyromellitic acid within a substantially linear range.

[Ethylene-vinyl alcohol copolymer]
Although it does not specifically limit as an ethylene vinyl alcohol copolymer used by this embodiment, Preferably it is 15-60 mol%, More preferably, it is 20-55 mol%, More preferably, it is 29-44 mol%. The saponification degree of the vinyl acetate component is preferably 90 mol% or more, more preferably 95 mol% or more.
Further, the ethylene vinyl alcohol copolymer has a smaller amount of α-olefin such as propylene, isobutene, α-octene, α-dodecene, α-octadecene, unsaturated carboxylic acid, etc., as long as the effect of the present embodiment is not adversely affected. A comonomer such as an acid or a salt thereof, a partial alkyl ester, a complete alkyl ester, a nitrile, an amide, an anhydride, an unsaturated sulfonic acid or a salt thereof may be contained.

[Plant-derived resin]
The plant-derived resin used in the present embodiment is not particularly limited as long as it is a resin containing a plant-derived material as a raw material. Specific examples include aliphatic polyester-based biodegradable resins. Examples of the aliphatic polyester-based biodegradable resin include poly (α-hydroxy acids) such as polyglycolic acid (PGA) and polylactic acid (PLA); polybutylene succinate (PBS), polyethylene succinate (PES), and the like. And polyalkylene alkanoates.

[Chlorine resin]
The chlorine-based resin used in the present embodiment may be a resin containing chlorine as a structural unit, and a known resin can be used. Specific examples include polyvinyl chloride, polyvinylidene chloride, and copolymers of these with vinyl acetate, maleic acid derivatives, higher alkyl vinyl ethers, and the like.

  The oxygen-absorbing multilayer body of the present embodiment may include an arbitrary layer depending on the desired performance in addition to the oxygen-absorbing layer (layer A) and layer B. Examples of such an arbitrary layer include an adhesive layer.

  In the oxygen-absorbing multilayer body of this embodiment, when practical interlayer adhesive strength cannot be obtained between two adjacent layers, an adhesive layer (layer AD) may be provided between the two layers. preferable. 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 thereof include polyester-based thermoplastic elastomers mainly composed of a polyolefin resin and a polyester-based block copolymer. As the adhesive layer, it is preferable to use a modified resin of the same type as the thermoplastic resin used as the layer B from the viewpoint of adhesiveness. The thickness of the adhesive layer is preferably 2 to 100 μm, more preferably 5 to 90 μm, and still more preferably 10 to 80 μm, from the viewpoint of ensuring molding processability while exhibiting practical adhesive strength.

[Oxygen absorbing container]
Although the shape of the oxygen-absorbing container of the present embodiment is not limited at all, a multilayer injection molded article is preferably used. The production method and layer structure of the multilayer injection molded article are not particularly limited, and can be produced by a normal injection molding method. For example, using a molding machine equipped with two or more injection machines and an injection mold, the material constituting the layer A and the material constituting the layer B are passed from the respective injection cylinders through the mold hot runner into the cavity. The multilayer injection molded product corresponding to the shape of the injection mold can be manufactured. First, the material constituting the layer B is injected from the injection cylinder, then the material constituting the layer A is injected from another injection cylinder simultaneously with the resin constituting the layer B, and then the resin constituting the layer B By injecting the required amount to fill the cavity, a multilayer injection molded body having a three-layer structure B / A / B can be manufactured.
In addition, first, the material constituting the layer B is injected, then the material constituting the layer A is injected alone, and finally the material constituting the layer B is injected by a necessary amount to fill the mold cavity. A multilayer injection molded article having a five-layer structure B / A / B / A / B can be produced.
First, the material constituting the layer B1 is injected from the injection cylinder, then the material constituting the layer B2 is injected from another injection cylinder simultaneously with the resin constituting the layer B1, and then the resin constituting the layer A Is injected at the same time as the resin constituting the layers B1 and B2, and then the required quantity of the resin constituting the layer B1 is injected to fill the cavity, thereby providing a multi-layer injection of B1 / B2 / A / B2 / B1. A molded body can be produced.
In order to give heat resistance to the mouth and neck of the obtained molded body, the mouth and neck may be crystallized by heat treatment at this stage. The degree of crystallinity is preferably 30 to 50%, more preferably 35 to 45%. In addition, you may implement crystallization, after giving the secondary process mentioned later.
Moreover, you may shape | mold into a desired container shape by shaping | molding means, such as extrusion molding and compression molding (sheet molding, blow molding).

  In the case where the multilayer body itself of the present embodiment is a container, in addition to oxygen that slightly enters from the outside of the container, oxygen in the container can be absorbed, and alteration of the stored content article due to oxygen can be prevented.

  The shape of the oxygen-absorbing multilayer body of the present embodiment is not particularly limited, and can be any shape depending on the mold. Considering that the oxygen-absorbing multilayer body of the present embodiment can exhibit oxygen absorption performance, the oxygen-absorbing multilayer body of the present embodiment is preferably a storage container such as a cup-shaped container or a bottle-shaped container. . Moreover, it is also preferable that the multilayer body of this embodiment is a test tubular preform (parison) for secondary processing such as blow molding as described later, such as a PET bottle.

  The container obtained by secondary processing of the oxygen-absorbing multilayer body of the present embodiment absorbs oxygen in the container in addition to oxygen that slightly enters from the outside of the container, and prevents alteration of the stored content article due to oxygen. can do. Examples of secondary processing include blow molding and stretch blow molding, and examples of containers obtained by secondary processing include bottles.

In blow molding, first, a test tubular preform (parison) is molded as the oxygen-absorbing multilayer body of the present embodiment, and then the mouth of the heated preform is fixed with a jig, and the preform is molded into a final shape mold. It can be formed into a bottle shape by fitting it into the air, blowing air from the mouth, inflating the preform, bringing it into close contact with the mold, and cooling and solidifying it.
In blow molding, the mouth of the heated preform is fixed with a jig, the preform is fitted into the final shape mold, air is blown from the mouth while stretching with a stretching rod, and the preform is blow-stretched. It can be formed into a bottle shape by allowing it to adhere to a mold and cooling and solidifying.
The blow molding method is roughly classified into a hot parison method and a cold parison method. The former blow-molds in a softened state without completely cooling the preform. On the other hand, in the latter cold parison method, the preform is formed as a supercooled bottomed preform that is considerably smaller than the dimensions of the final shape and the resin is amorphous, and this preform is preheated to its stretching temperature to obtain the final shape. It is suitable for mass production by drawing in the mold in the axial direction and blow-drawing in the circumferential direction. In any method, the multilayer preform is heated to a stretching temperature equal to or higher than the glass transition temperature (Tg) and then stretched by a stretch rod molding method in a final shape mold heated to a heat treatment (heat set) temperature. The film is stretched in the longitudinal direction and stretched in the transverse direction by blow air. The draw ratio of the final blow molded article is preferably 1.2 to 6 times in the longitudinal direction and 1.2 to 4.5 times in the transverse direction.

  The above-described final shape mold is heated to a temperature at which resin crystallization is promoted, for example, 120 to 230 ° C., preferably 130 to 210 ° C. for PET resin, and the outer side of the wall of the molded body is molded at the time of blowing. Heat treatment is performed by contacting the inner surface for a predetermined time. After the heat treatment for a predetermined time, the inner layer is cooled by switching the blowing fluid to the internal cooling fluid. The heat treatment time varies depending on the thickness and temperature of the blow molded article, but is generally 1.5 to 30 seconds, preferably 2 to 20 seconds in the case of a PET resin. On the other hand, the cooling time varies depending on the heat treatment temperature and the type of cooling fluid, but is generally 0.1 to 30 seconds, preferably 0.2 to 20 seconds. Each part of the compact is crystallized by this heat treatment.

  As the cooling fluid, in addition to air at normal temperature, various gases cooled, for example, nitrogen at −40 ° C. to + 10 ° C., air, carbon dioxide, etc., a chemically inert liquefied gas such as liquefied nitrogen gas, liquefied Carbon dioxide gas, liquefied trichlorofluoromethane gas, liquefied dichlorodifluoromethane gas, other liquefied aliphatic hydrocarbon gases, and the like can be used. In this cooling fluid, a liquid mist having a large heat of vaporization such as water can coexist. By using the cooling fluid described above, a remarkably high cooling temperature can be obtained. In addition, two molds are used for stretch blow molding, and after heat treatment within a predetermined temperature and time range in the first mold, the blow molded body is transferred to the second mold for cooling, and again. You may cool a blow molded object simultaneously with blowing. The outer layer of the blow molded article taken out from the mold is cooled by cooling or by blowing cold air.

  As another method for producing a blow molded article, the multilayer preform is formed into a primary blow molded article having a size larger than that of the final blow molded article using a primary stretch blow mold, and then the primary blow molded article is heated and shrunk. Then, a two-stage blow molding may be employed in which a stretch blow molding is performed using a secondary mold to obtain a final blow molded body. According to this method for producing a blow molded article, the bottom of the blow molded article is sufficiently stretched and thinned to obtain a blow molded article excellent in hot filling, deformation of the bottom during heat sterilization, and impact resistance. .

The molded body of this embodiment and a container obtained by secondary processing thereof may be coated with an inorganic or inorganic oxide vapor deposition film or an amorphous carbon film.
Examples of the inorganic substance or inorganic oxide include aluminum, alumina, and silicon oxide. The vapor deposition film of an inorganic substance or an inorganic oxide can shield eluents, such as acetaldehyde and formaldehyde, from the injection molded object of this embodiment and the container obtained by carrying out a secondary process. The formation method of a vapor deposition film is not specifically limited, For example, physical vapor deposition methods, such as a vacuum evaporation method, sputtering method, and an ion plating method, Chemical vapor deposition methods, such as PECVD, etc. are mentioned. The thickness of the deposited film is preferably 5 to 500 nm, more preferably 5 to 200 nm, from the viewpoints of gas barrier properties, light shielding properties, bending resistance, and the like.
The amorphous carbon film is a diamond-like carbon film, which is a hard carbon film also called i-carbon film or hydrogenated amorphous carbon film. Examples of the method for forming the film include a method in which the inside of the hollow molded body is evacuated by evacuation, a carbon source gas is supplied thereto, and plasma generating energy is supplied by supplying plasma generating energy, Thereby, an amorphous carbon film can be formed on the inner surface of the container. The amorphous carbon film not only can remarkably reduce the permeability of low-molecular inorganic gases such as oxygen and carbon dioxide, but can also suppress the sorption of various low-molecular organic compounds having an odor. The thickness of the amorphous carbon film is preferably 50 to 5000 nm from the viewpoint of the effect of suppressing the sorption of the low molecular organic compound, the effect of improving the gas barrier property, the adhesion to the plastic, the durability and the transparency.

  In addition, the oxygen-absorbing multilayer body of the present invention and the container obtained by secondary processing thereof should be sterilized in a form suitable for the storage object before and after filling with the storage object. Can do. Sterilization methods include hot water treatment at 100 ° C. or lower, pressurized hot water treatment at 100 ° C. or higher, heat sterilization such as ultra-high temperature heat treatment at 130 ° C. or higher, electromagnetic wave sterilization of ultraviolet rays, microwaves, gamma rays, etc., ethylene oxide And gas sterilization such as hydrogen peroxide and hypochlorous acid.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Unless otherwise stated, NMR measurements were performed at room temperature. Moreover, in the present Example and the comparative example, various physical-property values were measured with the following measuring methods and measuring apparatuses.

(Measurement method of glass transition temperature)
The glass transition temperature was measured according to JIS K7122. The measuring apparatus used was “DSC-60” manufactured by Shimadzu Corporation.

(Measuring method of melting point)
The melting point was determined by measuring the DSC melting point peak temperature according to ISO11357. The measuring apparatus used was “DSC-60” manufactured by Shimadzu Corporation.

(Measurement method of number average molecular weight)
The number average molecular weight was measured by GPC-LALLS. As a measuring apparatus, “Shodex GPC-2001” manufactured by Showa Denko KK was used.

[Monomer synthesis example]
An autoclave having an internal volume of 18 L was charged with 2.20 kg of dimethyl naphthalene-2,6-dicarboxylate, 11.0 kg of 2-propanol, and 350 g (50 wt% water-containing product) of 5% palladium supported on activated carbon. Next, after the air in the autoclave was replaced with nitrogen, and further nitrogen was replaced with hydrogen, hydrogen was supplied until the pressure in the autoclave reached 0.8 MPa. Next, the agitator was started, the rotation speed was adjusted to 500 rpm, the internal temperature was raised to 100 ° C. over 30 minutes, and hydrogen was further supplied to make the pressure 1 MPa. Thereafter, the supply of hydrogen was continued to maintain 1 MPa in accordance with the pressure drop due to the progress of the reaction. Since the pressure drop disappeared after 7 hours, the autoclave was cooled, unreacted residual hydrogen was released, and then the reaction solution was taken out from the autoclave. The reaction solution was filtered to remove the catalyst, and then 2-propanol was evaporated from the separated filtrate with an evaporator. To the resulting crude product, 4400 g of 2-propanol was added and purified by recrystallization to obtain dimethyl tetralin-2,6-dicarboxylate in a yield of 80%. The NMR analysis results are as follows. 1H-NMR (400 MHz CDCl ₃ ) δ7.76-7.96 (2H m), 7.15 (1H d), 3.89 (3H s), 3.70 (3H s), 2.70-3.09 (5H m), 1.80-1.95 (1H m ).

[Polymer production example]
(Production Example 1)
Tetralin-2,6-dicarboxylic acid obtained in the monomer synthesis example in a polyester resin production apparatus equipped with a fractionator, a total condenser, a cold trap, a stirrer, a heating device, and a nitrogen introduction pipe, etc. Dimethyl 543 g, 1,4-butanediol 315 g, and tetrabutyl titanate 0.171 g were charged, and the temperature was raised to 230 ° C. in a nitrogen atmosphere to perform a transesterification reaction. After setting the reaction conversion rate of the dicarboxylic acid component to 85% or more, 0.171 g of tetrabutyl titanate is added, the temperature is increased and the pressure is gradually reduced, polycondensation is performed at 245 ° C. and 133 Pa or less, and the polyester compound (1) Got.

As a result of measuring the weight average molecular weight and number average molecular weight of the obtained polyester compound (1) by GPC (gel permeation chromatography), the weight average molecular weight in terms of polystyrene was 8.7 × 10 ⁴ , and the number average molecular weight was It was 3.1 × 10 ⁴ . As a result of measuring the glass transition temperature and the melting point by DSC, the glass transition temperature was 36 ° C. and the melting point was 145 ° C.

(Production Example 2)
A polyester compound (2) was synthesized in the same manner as in Production Example 1 except that 1,4-butanediol of Production Example 1 was changed to ethylene glycol and its weight was changed to 217 g. The weight average molecular weight in terms of polystyrene of the polyester compound (2) was 8.5 × 10 ⁴ , the number average molecular weight was 3.0 × 10 ⁴ , the glass transition temperature was 67 ° C., and the melting point was not recognized because it was amorphous.

(Production Example 3)
A polyester compound (3) was synthesized in the same manner as in Production Example 1 except that 1,4-butanediol in Production Example 1 was changed to 1,6-hexanediol and its weight was changed to 413 g. The weight average molecular weight of the polyester compound (3) was 8.9 × 10 ⁴ , the number average molecular weight was 3.3 × 10 ⁴ , the glass transition temperature was 16 ° C., and the melting point was 137 ° C.

Example 1
15 kg / h in a twin-screw extruder having two screws with a diameter of 37 mm and dry blended with cobalt acetate (II) to 0.02 parts by mass with respect to 100 parts by mass of the polyester compound (1) The above materials were supplied and melt kneaded under the condition of a cylinder temperature of 220 ° C., the strand was extruded from the extruder head, cooled, and pelletized to obtain an oxygen-absorbing resin composition.

  Next, an injection molded article (parison) having a three-layer structure composed of layer B / layer A / layer B was molded under the following conditions. The total mass of the parison was 25 g, and the mass of the layer A was 10% by mass of the total mass of the parison. In addition, as the resin constituting the layer B, polyethylene terephthalate (manufactured by Nippon Unipet Co., Ltd., trade name: BK-2180) was used, and as the resin constituting the layer A, the above oxygen-absorbing resin composition was used. .

(Parison shape)
The total length was 95 mm, the outer diameter was 22 mm, and the wall thickness was 2.7 mm. For the manufacture of the parison, an injection molding machine (manufactured by Meiki Seisakusho Co., Ltd., model: M200, 4 pieces) was used.
(Parison molding conditions)
Injection cylinder temperature for layer A: 250 ° C
Injection cylinder temperature for layer B: 280 ° C
Resin channel temperature in mold: 280 ° C
Mold cooling water temperature: 15 ° C

  After cooling the obtained parison, as a secondary process, the parison was heated and biaxial stretch blow molding was performed to produce a bottle.

(Bottle shape obtained by secondary processing)
The total length was 160 mm, the outer diameter was 60 mm, the inner volume was 350 ml, and the wall thickness was 0.28 mm. The draw ratio was 1.9 times in length and 2.7 times in width. The bottom shape is a champagne type. The body has dimples. For secondary processing, a blow molding machine (manufactured by Frontier Corporation, model: EFB1000ET) was used.
(Secondary processing conditions)
Parison heating temperature: 100 ° C
Stretching rod pressure: 0.5 MPa
Primary blow pressure: 0.7 MPa
Secondary blow pressure: 2.5 MPa
Primary blow delay time: 0.33 sec
Primary blow time: 0.35 sec
Secondary blow time: 2.0 sec
Blow exhaust time: 0.6 sec
Mold temperature: 30 ° C.

  The obtained multilayer bottle was filled with 350 mL of gyokuro tea, sealed, and stored at 35 ° C. The flavor of gyokuro tea after 30 days, 60 days and 90 days was investigated.

(Example 2)
A multilayer bottle was produced in the same manner as in Example 1 except that the polyester compound (1) was changed to the polyester compound (2), and the same storage test as in Example 1 was performed. The evaluation results are shown in Table 1.

(Example 3)
A multilayer bottle was produced in the same manner as in Example 1 except that the polyester compound (1) was changed to the polyester compound (3), and the same storage test as in Example 1 was performed. The evaluation results are shown in Table 1.

(Comparative Example 1)
A single-layer bottle having the same shape as in Example 1 was prepared using polyethylene terephthalate (trade name: BK-2180, manufactured by Nippon Unipet Co., Ltd.), and the same storage test as in Example 1 was performed. The evaluation results are shown in Table 1.

  As is clear from Examples 1 to 3, the oxygen-absorbing multilayer container of the present invention was excellent in oxygen absorption performance, maintained the flavor of gyokuro tea, and was suitable for storage of gyokuro tea.

  On the other hand, the comparative example 1 evaluated with the PET single layer bottle did not have an oxygen absorption function, and the flavor of gyokuro tea was remarkably lowered.

Claims (4)

Oxygen containing liquid tea or pasty tea with an oxygen-absorbing layer (layer A) made of an oxygen-absorbing resin composition containing a polyester compound and a transition metal catalyst, and a resin layer (layer B) containing a thermoplastic resin A method for preserving liquid tea or pasty tea, which is stored in an oxygen-absorbing container using all or part of the absorbent multilayer body,
The polyester compound is represented by the following general formulas (1) to (4).

(In the formula, each R independently represents a hydrogen atom or a monovalent substituent, and the monovalent substituent is a halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, cyano group, A group consisting of a group, a hydroxy group, a carboxyl group, an ester group, an amide group, a nitro group, an alkoxy group, an aryloxy group, an acyl group, an amino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, and an imide group At least one selected from the above, which may further have a substituent, m represents an integer of 0 to 3, n represents an integer of 0 to 7, and at least one hydrogen atom at the benzyl position of the tetralin ring. X is an aromatic hydrocarbon group, a saturated or unsaturated alicyclic hydrocarbon group, a linear or branched saturated or unsaturated aliphatic hydrocarbon group, and a heterocyclic ring. It represents a divalent group containing at least one group selected from the group consisting of.)
Containing a structural unit having at least one tetralin ring selected from the group consisting of:
A method for preserving liquid tea or pasty tea.   The storage method according to claim 1, wherein the transition metal catalyst contains at least one transition metal selected from the group consisting of manganese, iron, cobalt, nickel, and copper.   The storage method according to claim 1 or 2, wherein the transition metal catalyst is contained in an amount of 0.001 to 10 parts by mass as a transition metal amount with respect to 100 parts by mass of the polyester compound. The storage method according to any one of claims 1 to 3, wherein the structural unit represented by the general formula (1) is at least one selected from the group consisting of the following formulas (5) to (7).