JP2022007521A - Resin composition, molding, laminate, pipe, pipe for hot water circulation, heat insulation multilayer pipe, and pipe for fuel - Google Patents

Abstract

To provide a resin composition which gives a molding that suppresses occurrence of spitting during melt-molding, has sufficient heat and light resistances and is less likely to be formed into micro-plastic after disposal, and sufficiently improves each of the above characteristics compared to those using an ethylene-vinyl alcohol copolymer (EVOH).SOLUTION: A resin composition contains an EVOH (A), aluminum ions (B) and an antioxidant (G), in which at least a part of the EVOH (A) has at least one of a carboxylic acid unit (I) and a lactone ring unit (II) positioned on the polymer terminal, the total content (i+ii) of the carboxylic acid unit (I) and the lactone ring unit (II) per 1 g of the EVOH (A) is 14 μmol/g or more and 78 μmol/g or less, and a content (b) of the aluminum ions (B) per 1 g of the EVOH (A) is 0.002 μmol/g or more and 0.17 μmol/g or less.SELECTED DRAWING: None

Description

The present invention relates to resin compositions, molded bodies, laminates, pipes, hot water circulation pipes, heat insulating multilayer pipes, and fuel pipes.

Generally, an ethylene-vinyl alcohol copolymer (hereinafter, also referred to as “EVOH”) is excellent in transparency, gas barrier property, fragrance retention property, solvent resistance, oil resistance and the like. Taking advantage of these characteristics, EVOH is used in films, sheets, containers and the like as packaging materials for foods, pharmaceuticals, industrial chemicals, pesticides and the like. In addition, EVOH is also used in fuel tanks for automobiles and other vehicles, tube materials for tires, agricultural films, geomembranes, cushioning materials for shoes, etc. by taking advantage of its barrier properties, heat retention properties, stain resistance, etc. ing. Further, the EVOH resin composition containing an antioxidant is molded into a hot water circulation pipe, a fuel pipe, or the like for floor heating, district heating, or the like, and is used.

EVOH has lower thermal stability than other resins, and may cause bumps during heat treatment and molding. Further, EVOH may have a reduced mechanical strength when exposed to light, heat or the like due to outdoor use. Regarding the thermal stability of EVOH, Patent Document 1 includes ethylene unit (III), vinyl alcohol unit (IV) and vinyl ester unit (V), and the ratio of ethylene unit (III) to the total of the above units (III + IV + V). Is 20 to 60 mol%, and the ratio of the total (I + II) of the carboxylic acid group unit (I) and the lactone ring unit (II) at the polymer terminal of the copolymer to the total (III + IV + V) of the above units is 0.12 mol% or less. EVOH is described. According to Patent Document 1, EVOH having a small number of terminal carboxylic acid units and lactone ring units is less likely to cause lumps during heat treatment and molding, and improves long-running properties during melt molding.

In addition, in the recent trend of resource saving and energy saving, many district heat supply (district heating and cooling) systems have been introduced. The district heating system supplies hot and cold water, etc. from a single air-conditioning / hot-water supply facility to a plurality of buildings by means of a laid pipeline. A heat insulating multi-layer pipe consisting of an inner pipe carrying gas or liquid, a heat insulating foam layer covering the inner pipe, and an outer pipe covering the heat insulating foam layer is used as a pipe of a regional heat supply system, and the heat insulating foam layer is used. , Carbon dioxide, pentane, cyclopentane and the like are used as a heat insulating foaming agent. If a pipe that does not have an oxygen barrier property is used in the pipeline, oxygen will permeate through the pipe and dissolve into the circulating water, which may promote corrosion of metal parts in the system piping. Therefore, in order to maintain the system for a long period of time, a multi-layer pipe having an EVOH layer is often used. However, the progress of oxidative deterioration of EVOH due to oxygen in the air during long-term use has become a problem. When the mechanical strength decreases due to this oxidative deterioration and cracks parallel to the length direction of the EVOH layer are generated, foaming gas diffuses from the pipe, not only the heat insulating performance deteriorates, but also the corrosion of the metal part of the system progresses. do. In order to solve such a problem, it is required to further extend the life of the EVOH layer.

Regarding such a problem of oxidative deterioration of the EVOH layer, Patent Document 2 states that with respect to 100 parts by mass of an ethylene-vinyl alcohol copolymer, 0.001 to 5 parts by mass of an antioxidant and a conjugated polyene having a molecular weight of 1000 or less are used. Molds and multilayer pipes having a layer made of a resin composition containing 0.00001 to 0.3 parts by mass of a compound are described, and these generate cracks in the EVOH layer due to oxidative deterioration when used at high temperatures for a long period of time. It is difficult to do so and is said to have excellent gas barrier properties.

International Publication No. 2004/092234 International Publication No. 2011/125736

The EVOH of Patent Document 1 has a ratio of the total (I + II) of the carboxylic acid unit (I) and the lactone ring unit (II) of 0.12 mol% or less, and is thermally stable in EVOH having a high total ratio. It has not been possible to improve the properties, that is, to suppress the lumps generated during heat treatment and molding. Further, the EVOH of Patent Document 1 and the molded product of Patent Document 2 are not considered for heat resistance and light resistance in consideration of long-term outdoor use. Furthermore, in recent years, it has become a problem that discarded plastic products flow out into the ocean and become microplastics that pollute the ocean. Therefore, there is a demand for the development of a resin that is difficult to make into microplastic. In particular, as shown in Table 11 (Reference Comparative Examples 18 to 20) of Examples described later, the total of the carboxylic acid unit (I) and the lactone ring unit (II) such as EVOH of Patent Document 1 above. The inventors have found that those having a low ratio of (I + II) are likely to be microplasticized.

On the other hand, the properties of EVOH such as thermal stability and heat resistance and light resistance are influenced by the structure of EVOH itself such as ethylene content. Therefore, it is possible to improve the thermal stability, heat resistance and light resistance, etc. to some extent by adjusting the ethylene content and the like. However, since EVOH having a suitable ethylene content or the like according to the intended use of the molded product is usually used, each property such as thermal stability and heat resistance and light resistance should be improved without changing the EVOH itself. Is desired. Further, even when a pipe obtained from a resin composition containing EVOH is used at a high temperature for a long period of time, it is desired that cracks due to oxidative deterioration are less likely to occur in the EVOH layer.

The present invention has been made based on the above circumstances, and an object thereof is a molded body which suppresses the generation of lumps during melt molding, has sufficient heat and light resistance, and is difficult to be microplasticized after disposal. Is a resin composition that can be obtained, and each of the above characteristics is sufficiently improved as compared with the one using the same EVOH, and even when a pipe or the like is obtained and used at a high temperature for a long period of time, It is an object of the present invention to provide a resin composition in which cracks are less likely to occur in the EVOH layer due to oxidative deterioration, and a molded body, a laminated body, a pipe, or the like using this resin composition.

According to the present invention, the above object is
[1] A resin composition containing an ethylene-vinyl alcohol copolymer (A), an aluminum ion (B) and an antioxidant (G), which is at least a part of the ethylene-vinyl alcohol copolymer (A). Has at least one of the carboxylic acid unit (I) and the lactone ring unit (II) located at the end of the polymer, and the carboxylic acid unit (I) and the lactone ring per 1 g of the ethylene-vinyl alcohol copolymer (A). The total content (i + ii) of the unit (II) is 14 μmol / g or more and 78 μmol / g or less, and the content (b) of the aluminum ion (B) per 1 g of the ethylene-vinyl alcohol copolymer (A) is 0. It is 002 μmol / g or more and 0.17 μmol / g or less, and the content (g) of the antioxidant (G) with respect to the ethylene-vinyl alcohol copolymer (A) is 0.01% by mass or more and 5% by mass or less. Resin composition;
[2] The ratio ((i + ii) / b) of the total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) to the content (b) of the aluminum ion (B) is 180 or more and 20. The resin composition of [1], which is 000 or less;
[3] The resin composition of [1] or [2], wherein the aluminum ion (B) is derived from a fatty acid aluminum salt having 5 or less carbon atoms;
[4] Further contains at least one compound (C) selected from the group consisting of cinnamon acids and conjugated polyene compounds having a molecular weight of 1,000 or less, and the compound (C) contained in the ethylene-vinyl alcohol copolymer (A). The resin composition according to any one of [1] to [3], wherein the amount (c) is 1 ppm or more and 1,000 ppm or less.
[5] When the ratio (ii / (i + ii)) of the content (ii) of the lactone ring unit (II) to the total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) is 40 mol% or more. A resin composition according to any one of [1] to [4];
[6] The thermoplastic elastomer (F) is further contained, and the mass ratio (F / A) of the thermoplastic elastomer (F) to the ethylene-vinyl alcohol copolymer (A) is 5/95 or more and 35/65 or less. , [1] to [5];
[7] The resin composition of [6], wherein the thermoplastic elastomer (F) is at least one selected from the group consisting of a polyester-based thermoplastic elastomer, a polystyrene-based thermoplastic elastomer, and a polyolefin-based thermoplastic elastomer;
[8] A molded product molded from the resin composition according to any one of [1] to [7];
[9] A laminate having a layer made of the resin composition according to any one of [1] to [7] and at least one other layer;
[10] A pipe having a layer made of the resin composition according to any one of [1] to [7];
[11] A hot water circulation pipe composed of the pipes of [10];
[12] A heat insulating multi-layer pipe composed of the pipe of [10] further having a heat insulating foam layer;
[13] A fuel pipe consisting of the pipes of [10];
Achieved by providing one of the above.

According to the present invention, it is a resin composition that suppresses the generation of lumps during melt molding, has sufficient heat resistance and light resistance, and can obtain a molded product that is difficult to be microplasticized after disposal, and uses the same EVOH. In comparison, each of the above characteristics has been sufficiently improved, and a resin composition in which cracks due to oxidative deterioration are less likely to occur in the EVOH layer even when the EVOH layer is used at a high temperature for a long period of time when a pipe or the like is obtained, and It is possible to provide a molded body, a laminated body, a thermoformed container, a blow molded container, a film, an agricultural film, a plant medium, a pipe and the like using this resin composition.

Solvent: DMSO-d ₆ Measurement temperature: ¹ H-NMR spectrum of EVOH-A of Synthesis Example 1 measured under the condition of 25 ° C. Solvent: DMSO-d ₆ Measurement temperature: ¹ H-NMR spectrum of EVOH-A of Synthesis Example 1 measured under the condition of 80 ° C. ¹ H-NMR spectrum of EVOH-A of Synthesis Example 1 measured under the condition of solvent: D ₂ O + MeOD measurement temperature: 80 ° C.

<Resin composition>
The resin composition of the present invention contains an ethylene-vinyl alcohol copolymer (A) (hereinafter, may be referred to as "EVOH (A)"), an aluminum ion (B), and an antioxidant (G). .. At least a portion of EVOH (A) has at least one of a carboxylic acid unit (I) and a lactone ring unit (II) located at the end of the polymer. The total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) per 1 g of EVOH (A) is 14 μmol / g or more and 78 μmol / g or less. The content (b) of aluminum ions (B) per 1 g of EVOH (A) is 0.002 μmol / g or more and 0.17 μmol / g or less. The content (g) of the antioxidant (G) with respect to EVOH (A) is 0.01% by mass or more and 5% by mass or less.

The resin composition of the present invention is a resin composition that suppresses the generation of lumps during melt molding, has sufficient heat resistance and light resistance, and can obtain a molded product that is difficult to be microplasticized after disposal, and the same EVOH is used. Each of the above characteristics is sufficiently improved as compared with the above. Therefore, according to the resin composition of the present invention, the generation of lumps is further suppressed without changing the type of EVOH, and the heat resistance and light resistance and the resistance to microplasticization of the obtained molded product are enhanced. The reason for this effect is not clear, but the following is presumed. A stable structure is formed by the interaction of a predetermined amount of aluminum ion (B) with the carboxylic acid unit (I) and the lactone ring unit (II) located at the terminal of EVOH (A). As a result, gelation during melt molding is suppressed, and as a result, the generation of lumps is suppressed. Further, it is presumed that the obtained molded product also has excellent heat resistance and light resistance as a result of forming the above stable structure, and it is difficult to make it into microplastic after disposal.

Further, the resin composition of the present invention contains a predetermined amount of the antioxidant (G), and also contains the total content of the carboxylic acid unit (I) and the lactone ring unit (II) per 1 g of EVOH (A) ( i + ii) is 14 μmol / g or more and 78 μmol / g or less, and the content (b) of aluminum ion (B) per 1 g of EVOH (A) is 0.002 μmol / g or more and 0.17 μmol / g or less. It has excellent oxidative deterioration resistance and heat and light resistance, and even when a pipe or the like is used at high temperature for a long period of time, the EVOH layer is less likely to crack due to oxidative deterioration, and the gas barrier property is also reduced. It's hard to do. Although the reason for this is not clear, in addition to the effect of the antioxidant (G), the carboxylic acid unit (I) and the lactone ring unit (I) in which the above-mentioned predetermined amount of aluminum ion (B) is located at the end of EVOH (A) ( It is presumed that the stable structure formed by interacting with II) also enhances oxidative deterioration resistance.

The resin composition of the present invention may further contain components other than EVOH (A), aluminum ion (B) and antioxidant (G). Hereinafter, each component and the like of the resin composition of the present invention will be described in detail.

(EVOH (A))
EVOH (A) is a copolymer having an ethylene unit and a vinyl alcohol unit. EVOH (A) is usually obtained by a saponification reaction of an ethylene-vinyl ester copolymer. Therefore, EVOH (A) may further have the remaining vinyl ester units. That is, EVOH (A) is a copolymer having an ethylene unit and a vinyl alcohol unit, and further having or not having a vinyl ester unit as an arbitrary monomer unit. The ethylene-vinyl ester copolymer can be produced and saponified by a known method. Vinyl acetate is a typical vinyl ester, but other fatty acid vinyls such as vinyl formate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl pivalate and vinyl versatic acid. It may be an ester.

At least a portion of EVOH (A) has at least one of a carboxylic acid unit (I) and a lactone ring unit (II) located at the polymer terminal (main chain terminal). The carboxylic acid unit (I) is a structural unit located at the end of the polymer and refers to a structural unit having a carboxy group. The carboxylic acid unit (I) is also referred to as a terminal carboxylic acid unit. Some or all of the carboxy groups of the carboxylic acid unit (I) may be present in the salt or anion (-COO- ⁾ state. The lactone ring unit (II) is a structural unit located at the end of the polymer and refers to a structural unit having a lactone ring. The lactone ring unit (II) is also referred to as a terminal lactone ring unit. The number of ring members of the lactone ring is not particularly limited, and may be, for example, a 4- to 6-membered ring, preferably a 5-membered ring. The carboxylic acid unit (I) may be, for example, a structural unit represented by the following formula (1). The lactone ring unit (II) may be, for example, a structural unit represented by the following formula (2).

In formula (1), X is a hydrogen atom, a hydroxy group or an esterified hydroxy group. Y is a hydrogen atom or a metal atom.

Examples of the esterified hydroxy group represented by X include -OCO-CH ₃ , -OCO-C ₂ H ₅ , and the like.

Examples of the metal atom represented by Y include alkali metals such as sodium, alkaline earth metals such as magnesium and calcium, metals which are typical elements such as aluminum, and transition metals. Among them, typical elements are preferable, and alkali metals, alkaline earth metals and aluminum are preferable. When Y is aluminum, this aluminum is contained in the aluminum ion (B). When Y is a metal atom having a valence of 2 or more, two or more carboxylate anions (-COO- ⁾ may be bonded or coordinated to one Y.

The total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) per 1 g of EVOH (A), that is, the carboxylic acid unit (I) and the lactone ring unit (II) present in 1 g of EVOH (A). ) Is the lower limit of the total amount (amount of substance: number of moles) of 14 μmol / g, preferably 18 μmol / g, and more preferably 22 μmol / g. The lower limit of the total content of the carboxylic acid unit (I) and the lactone ring unit (II) with respect to the total content of the ethylene unit, vinyl alcohol unit and vinyl ester unit of EVOH (A) is preferably 0.10 mol%. 0.12 mol% is more preferable, and 0.14 mol% is further preferable. When the total content of the carboxylic acid unit (I) and the lactone ring unit (II) is at least the above lower limit, the interaction with the aluminum ion (B) is sufficiently generated, and the resistance to microplasticization is particularly improved.

On the other hand, the upper limit of the total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) per 1 g of EVOH (A) is 78 μmol / g, preferably 70 μmol / g, and 60 μmol / g. More preferably, 50 μmol / g is further preferable, and 40 μmol / g is particularly preferable. The upper limit of the total content of the carboxylic acid unit (I) and the lactone ring unit (II) with respect to the total content of the ethylene unit, vinyl alcohol unit and vinyl ester unit of EVOH (A) is preferably 0.4 mol%. 0.3 mol% is more preferable, and 0.25 mol% is further preferable. If there are too many carboxylic acid units (I) and lactone ring units (II), the thermal stability will decrease. Specifically, the carboxylic acid group unit (I) and the lactone ring unit (II) can react with the hydroxy group of EVOH (A) at a high temperature to form a polymer having a high degree of polymerization and having a branch. Therefore, if the content of the carboxylic acid unit (I) and the lactone ring unit (II) is large, the melt moldability of EVOH (A) tends to be lowered. Therefore, when the total content of the carboxylic acid unit (I) and the lactone ring unit (II) is not more than the above upper limit, the generation of lumps during melt molding can be suppressed.

Ratio of the content (ii) of the lactone ring unit (II) to the total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) of EVOH (A) (ii / (i + ii): lactone ring unit The lower limit of the ratio) may be, for example, 30 mol%, but 40 mol% is preferable, and 50 mol% is more preferable. When the lactone ring unit ratio (ii / (i + ii)) is equal to or higher than the above lower limit, heat resistance and microplasticization resistance tend to be further enhanced due to effective interaction with aluminum ion (B) and the like. be. On the other hand, the upper limit of the lactone ring unit ratio (ii / (i + ii)) may be, for example, 90 mol%, 80 mol% or 70 mol%.

The total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) per 1 g of EVOH (A) is adjusted by, for example, polymerization conditions such as the type of polymerization initiator, drying conditions such as a dry atmosphere, and the like. To. In EVOH (A) having no branched structure, the total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) tends to be relatively small when the degree of polymerization is high. In many cases, it does not follow the trend. For example, as described in Patent Document 1, the total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) is obtained by contacting the ethylene-vinyl ester copolymer or EVOH with a reducing agent. Can be reduced. On the contrary, the total content of the carboxylic acid unit (I) and the lactone ring unit (II) is contained by contacting the ethylene-vinyl ester copolymer or EVOH with an oxidizing agent or drying in an atmosphere that is easily oxidized. It is also possible to increase the amount (i + ii). Further, the ratio of the content (ii) of the lactone ring unit (II) to the total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) (ii / (i + ii): lactone ring unit ratio) is , Can be adjusted according to the saponification conditions. For example, when saponification is performed under the condition that saponification is promoted, the lactone ring unit ratio (ii / (i + ii)) tends to increase.

The total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) located at the polymer terminal of EVOH (A) and the lactone ring unit ratio (ii / (i + ii)) are ¹ H-NMR measurement. Is sought after. The inventors have found that the above measurement results differ depending on the type of solvent used in the measurement. Therefore, the above measurement shall be performed using a mixed solvent of water / methanol (mass ratio 4/6, but if the sample does not dissolve, the mass ratio is appropriately changed). Specifically, the total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) and the lactone ring unit ratio (ii / (i + ii)) are measured by the methods described in Examples described later. Value.

The lower limit of the ethylene unit content of EVOH (A) is preferably 10 mol%, more preferably 15 mol%, still more preferably 20 mol%, and even more preferably 25 mol%. On the other hand, the upper limit of the ethylene unit content of EVOH (A) is preferably 60 mol%, more preferably 55 mol%, and even more preferably 50 mol% or 45 mol%. By setting the content of ethylene units to the above lower limit or higher, thermal stability, resistance to microplasticization, and the like tend to be improved. Further, by setting the content of ethylene units to the above lower limit or less, the oxygen barrier property and the like tend to be improved.

The lower limit of the saponification degree of EVOH (A) is preferably 90 mol%, more preferably 95 mol%, further preferably 99 mol%, and particularly preferably 99.6 mol%. By setting the saponification degree of EVOH (A) to the above lower limit or higher, the melt moldability, the gas barrier property of the obtained molded product and the like, the heat resistance and light resistance, the moisture resistance and the like tend to be improved. Further, the saponification degree may be 100 mol% or less, 99.97 mol% or less, or 99.94 mol% or less.

EVOH (A) contains carboxylic acid units (I), lactone ring units (II), and units derived from ethylene, vinyl esters and other monomers other than the saponified product, as long as the effects of the present invention are not impaired. You may have. The content of EVOH (A) in all structural units of units derived from other monomers (units other than carboxylic acid unit (I), lactone ring unit (II), ethylene unit, vinyl ester unit and vinyl alcohol unit) is 30 mol% or less is preferable, 20 mol% or less is more preferable, 10 mol% or less is further preferable, 5 mol% or less is further preferable, and 1 mol% or less is particularly preferable. When EVOH (A) has a unit derived from the other monomer, the content thereof may be 0.05 mol% or more or 0.1 mol% or more.

Other monomers include unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid and itaconic acid or anhydrides, salts thereof, or mono or dialkyl esters; nitriles such as acrylonitrile and methacrylic acid; acrylamide and methacrylic. Amid such as amide; olefin sulfonic acid such as vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid or a salt thereof; vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tri (β-methoxy-ethoxy) silane, γ-methacrylic acid. Vinyl silane compounds such as propylmethoxysilane; alkyl vinyl ethers, vinyl ketones, N-vinylpyrrolidone, vinyl chloride, vinylidene chloride and the like can be mentioned.

The units derived from other monomers are represented by the structural unit (X) represented by the following formula (I), the structural unit (Y) represented by the following formula (II), and the following formula (III). It may be at least one of the structural units (Z) to be formed.

In the above formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ are independently hydrogen atoms and 1 to 10 carbon atoms, respectively. Represents an aliphatic hydrocarbon group, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or a hydroxyl group. A pair of R ¹ , R ² and R ³ , R ⁴ and R ⁵ , and R ⁶ and R ⁷ may be bonded (provided that a pair of R ¹ , R ² and R ³ are all hydrogen atoms. And when ^R4 and ^R5 , or ^R6 and ^R7 are both hydrogen atoms). In addition, some or all of the hydrogen atoms of the aliphatic hydrocarbon group having 1 to 10 carbon atoms, the alicyclic hydrocarbon group having 3 to 10 carbon atoms, and the aromatic hydrocarbon group having 6 to 10 carbon atoms are present. It may be substituted with a hydroxyl group, an alkoxy group, a carboxyl group or a halogen atom. In the above formula, R ¹² and R ¹³ independently represent a hydrogen atom, a formyl group, or an alkanoyl group having 2 to 10 carbon atoms.

When EVOH (A) has a structural unit (X), (Y) or (Z), the flexibility and processing characteristics of the resin composition are improved, and the stretchability and thermoformability in the obtained molded body or multilayer structure are improved. Etc. tend to be good.

In the structural unit (X), (Y) or (Z), examples of the aliphatic hydrocarbon group having 1 to 10 carbon atoms include an alkyl group and an alkenyl group. Examples of the alicyclic hydrocarbon group having 3 to 10 carbon atoms include a cycloalkyl group and a cycloalkenyl group. Examples of the aromatic hydrocarbon group having 6 to 10 carbon atoms include a phenyl group and the like.

In the structural unit (X), R ¹ , R ² and R ³ are preferably hydrogen atoms, methyl groups, ethyl groups, hydroxyl groups, hydroxymethyl groups and hydroxyethyl groups, respectively, and among them, the obtained multilayer structure and the like. From the viewpoint of further improving the stretchability and the thermoformability in the above, hydrogen atom, methyl group, hydroxyl group and hydroxymethyl group are more preferable independently.

The method of containing the structural unit (X) in the EVOH (A) is not particularly limited, and for example, in the polymerization of ethylene and vinyl ester, a method of copolymerizing a monomer induced by the structural unit (X) may be used. Can be mentioned. Examples of the monomer derived to the structural unit (X) include alkenes such as propylene, butylene, pentene, and hexene; 3-hydroxy-1-propene, 3-acyloxy-1-propene, and 3-acyloxy-1-butene. , 3-Hydroxy-1-butene, 4-hydroxy-1-butene, 4-acidoxy-1-butene, 3,4-diasiloxy-1-butene, 3-acidoxy-4-hydroxy-1-butene, 4-acidoxy -3-Hydroxy-1-butene, 3-Asiloxy-4-methyl-1-butene, 4-Asiloxy-2-methyl-1-butene, 4-Achilloxy-3-methyl-1-butene, 3,4-diasiloxy -2-Methyl-1-butene, 4-hydroxy-1-pentene, 5-hydroxy-1-pentene, 4,5-dihydroxy-1-pentene, 4-acidoxy-1-pentene, 5-acyloxy-1-pentene , 4,5-diasiloxy-1-pentene, 4-hydroxy-3-methyl-1-pentene, 5-hydroxy-3-methyl-1-pentene, 4,5-dihydroxy-3-methyl-1-pentene, 5 , 6-Dihydroxy-1-hexene, 4-hydroxy-1-hexene, 5-hydroxy-1-hexene, 6-hydroxy-1-hexene, 4-acyloxy-1-hexene, 5-acyloxy-1-hexene, 6 Examples thereof include alkenes having a hydroxyl group or an ester group such as asyloxy-1-hexene and 5,6-diasiloxy-1-hexene. Above all, from the viewpoint of copolymerization reactivity, processability of the obtained molded body and multilayer structure, and gas barrier property, propylene, 3-acyloxy-1-propene, 3-acyloxy-1-butene, 4-acyloxy-1 -Butene and 3,4-diasiloxy-1-butene are preferred. As "acyloxy", acetoxy is preferable, and specifically, 3-acetoxy-1-propene, 3-acetoxy-1-butene, 4-acetoxy-1-butene and 3,4-diacetoxy-1-butene are preferable. In the case of an ester-bearing alkene, it is induced to the structural unit (X) during the saponification reaction.

In the structural unit (Y), it is preferable that both R ⁴ and R ⁵ are hydrogen atoms. In particular, it is more preferable that both R ⁴ and R ⁵ are hydrogen atoms, one of R ⁶ and R ⁷ is an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and the other is a hydrogen atom. As the aliphatic hydrocarbon group, an alkyl group and an alkenyl group are preferable. From the viewpoint of particularly placing importance on the gas barrier property in the obtained molded body and the multilayer structure, it is more preferable that one of R ⁶ and R ⁷ is a methyl group or an ethyl group and the other is a hydrogen atom. Further, it is more preferable that one of R ⁶ and R ⁷ is a substituent represented by (CH ₂ ) _h OH (where h is an integer of 1 to 8) and the other is a hydrogen atom. In addition, h is preferably an integer of 1 to 4, more preferably 1 or 2, and even more preferably 1.

The method of containing the structural unit (Y) in EVOH (A) is not particularly limited, and a method of reacting EVOH obtained by a saponification reaction with a monovalent epoxy compound or the like is used. As the monovalent epoxy compound, compounds represented by the following formulas (IV) to (X) are preferably used.

In the above formula, R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ independently have a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms (alkyl group, alkenyl group, etc.), and 3 carbon atoms. It represents an alicyclic hydrocarbon group of about 10 (cycloalkyl group, cycloalkenyl group, etc.) or an aliphatic hydrocarbon group of 6 to 10 carbon atoms (phenyl group, etc.). Further, i, j, k, p and q each independently represent an integer of 1 to 8. However, when R ¹⁷ is a hydrogen atom, R ¹⁸ has a substituent other than the hydrogen atom.

Examples of the monovalent epoxy compound represented by the formula (IV) include epoxy ethane (ethylene oxide), epoxy propane, 1,2-epoxy butane, 2,3-epoxy butane, and 3-methyl-1,2-epoxy butane. , 1,2-Epoxypentane, 3-Methyl-1,2-Epoxypentane, 1,2-Epoxyhexane, 2,3-Epoxyhexane, 3,4-Epoxyhexane, 3-Methyl-1,2-Epoxyhexane , 3-Methyl-1,2-Epoxy Heptane, 4-Methyl-1,2-Epoxy Heptane, 1,2-Epoxy Octane, 2,3-Epoxy Octane, 1,2-Epoxy Nonan, 2,3-Epoxy Nonan , 1,2-epoxy decane, 1,2-epoxy dodecane, epoxy ethylbenzene, 1-phenyl-1,2-epoxy propane, 3-phenyl-1,2-epoxy propane and the like. Examples of the monovalent epoxy compound represented by the formula (V) include various alkyl glycidyl ethers and the like. Examples of the monovalent epoxy compound represented by the formula (VI) include various alkylene glycol monoglycidyl ethers. Examples of the monovalent epoxy compound represented by the formula (VII) include various alkenyl glycidyl ethers. Examples of the monovalent epoxy compound represented by the formula (VIII) include various epoxy alkanols such as glycidol. Examples of the monovalent epoxy compound represented by the formula (IX) include various epoxy cycloalkanes. Examples of the monovalent epoxy compound represented by the formula (X) include various epoxy cycloalkenes.

Among the monovalent epoxy compounds, an epoxy compound having 2 to 8 carbon atoms is preferable. In particular, from the viewpoint of ease of handling and reactivity, the monovalent epoxy compound preferably has 2 to 6 carbon atoms, and more preferably 2 to 4 carbon atoms. Further, the monovalent epoxy compound is particularly preferably a compound represented by the formula (IV) or the formula (V). Specifically, from the viewpoints of reactivity with EVOH (A), processability of the obtained multilayer structure and thermoformed body, gas barrier property, etc., 1,2-epoxybutane, 2,3-epoxybutane, and epoxy Propane, epoxy ethane or glycidole is preferred, with epoxy propane or glycidole being more preferred.

In the structural unit (Z), R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ are preferably a hydrogen atom or an aliphatic hydrocarbon group having 1 to 5 carbon atoms, preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and the like. An n-butyl group, an isobutyl group, a tert-butyl group or an n-pentyl group is preferable.

The method for containing the structural unit (Z) in EVOH (A) is not particularly limited, and examples thereof include the methods described in JP-A-2014-304647.

EVOH (A) may be used alone or in combination of two or more.

The lower limit of the content of EVOH (A) in the resin composition of the present invention may be, for example, 50% by mass, preferably 70% by mass, more preferably 80% by mass, still more preferably 90% by mass, and 95% by mass. , 97% by weight or 99% by weight may be even more preferred. On the other hand, the upper limit of the content of EVOH (A) may be, for example, 99.9% by mass, and may be 99% by mass, 95% by mass, or 90% by mass. The content of EVOH (A) means the content (content ratio) in the resin composition in a dry state. Hereinafter, the same applies to the content based on the resin composition.

(Aluminum ion (B))
The aluminum ion (B) contained in the resin composition of the present invention may exist in a state of being dissociated from the anion, or may exist in the state of a salt bonded to the anion. Further, it may exist in a state of being coordinated with a group or the like (for example, a carboxy group, a hydroxyl group, etc.) possessed by EVOH (A) or another arbitrary component.

The aluminum ion (B) is usually derived from a salt, but a fatty acid aluminum salt having 5 or less carbon atoms is preferable. That is, it is preferable that a fatty acid aluminum salt having 5 or less carbon atoms is used when preparing the resin composition of the present invention. In other words, in the resin composition of the present invention, it is preferable that a fatty acid aluminum salt having 5 or less carbon atoms is added or contained as a component constituting the aluminum ion (B). Aluminum salts of fatty acids having 5 or less carbon atoms have relatively high solubility in water. Therefore, even if a fatty acid aluminum salt having 5 or less carbon atoms is added in the manufacturing process, precipitation is unlikely to occur, and a resin composition or a molded product having an excellent appearance with few foreign substances can be obtained. The added fatty acid aluminum salt having 5 or less carbon atoms may be present in the resin composition in the form of a salt in which the aluminum ion (B) and the fatty acid anion are still bonded, and the aluminum ion (B) and the fatty acid may be present. It may be present in the resin composition in a state of being dissociated from the anion.

Examples of the fatty acid aluminum salt having 5 or less carbon atoms include aluminum formate (aluminum trigitate and the like), aluminum acetate, aluminum propionate (aluminum tripropionate and the like), aluminum butyrate (aluminum tributyrate and the like) and the like. Above all, it is preferable to use at least one of aluminum acetate and aluminum tripropionate. Here, aluminum acetate is a general term for those having the structure of an aluminum salt of acetic acid typified by basic aluminum acetate, trialuminum triacetate and the like. From the viewpoint of solubility in a solvent and the like, any one or two or more of these are appropriately used.

In addition, a fatty acid aluminum salt having 6 or more carbon atoms, an aluminum salt other than the fatty acid aluminum salt (aluminum nitrate, aluminum sulfate, etc.) and the like can also be used.

In the resin composition of the present invention, the content (b) of aluminum ion (B) per 1 g of EVOH (A), that is, the content of aluminum ion (B) based on the content (mass) of EVOH (A). The lower limit of (amount of substance: number of moles) is 0.002 μmol / g, preferably 0.005 μmol / g, and more preferably 0.01 μmol / g or 0.015 μmol / g. On the other hand, the upper limit of the content (b) is 0.17 μmol / g, preferably 0.15 μmol / g, more preferably 0.10 μmol / g, and further preferably 0.05 μmol / g or 0.03 μmol / g. It may be preferable. By setting the content (b) of aluminum ions (B) per 1 g of EVOH (A) within the above range, it is possible to sufficiently improve the suppression of the generation of lumps, heat resistance and light resistance, and resistance to microplasticization. In particular, by setting this content (b) within a relatively large range, the heat resistance and light resistance and the resistance to microplasticization tend to be greatly improved. On the other hand, by setting this content (b) within a relatively small range, the effect of suppressing the generation of lumps tends to be enhanced. Further, by setting the content (b) in the above range, the oxidation deterioration resistance and the like are also improved.

The ratio of the total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) located at the polymer terminal of EVOH (A) to the content (b) of the aluminum ion (B) ((i + ii)). As the lower limit of / b), 180 is preferable, 300 is more preferable, and 1,000 is more preferable. On the other hand, as the upper limit of this ratio ((i + ii) / b), 20,000 is preferable, 15,000 is more preferable, and 10,000, 8,000, 6,000 or 4,000 may be further preferable. .. By setting the ratio ((i + ii) / b) within the above range, it is possible to more sufficiently improve the suppression of the generation of lumps, the heat resistance and light resistance, and the resistance to microplasticization. In particular, by setting this ratio ((i + ii) / b) in a relatively high range, the excess aluminum ions (B) that do not contribute to the interaction with EVOH (A) are reduced, and thus the effect of suppressing the generation of lumps is reduced. Tends to increase. On the other hand, by setting the ratio ((i + ii) / b) to a relatively low range, the heat resistance and light resistance and the resistance to microplasticization tend to be further improved. Further, by setting the above ratio ((i + ii) / b) in the above range, the oxidation deterioration resistance and the like are also improved.

The lower limit of the content of aluminum ions (B) in the resin composition of the present invention may be, for example, 0.01 ppm, preferably 0.05 ppm, and more preferably 0.1 ppm. By setting the content of aluminum ions (B) in the entire resin composition to be equal to or higher than the above lower limit, the effect of the present invention can be further enhanced. On the other hand, as the upper limit of this content, 4 ppm is preferable, 3 ppm is more preferable, and 2 ppm or 1 ppm may be further preferable. By setting the content of aluminum ions (B) in the entire resin composition to be equal to or less than the above upper limit, it is possible to suppress the generation of lumps caused by excess aluminum ions (B).
In addition, in this specification, "ppm" indicates a mass-based content (content ratio).

(Compound (C))
The resin composition of the present invention preferably further contains compound (C). Compound (C) is at least one selected from the group consisting of cinnamon acids and conjugated polyene compounds. By further containing the compound (C) in the resin composition, it is possible to further improve the suppression of the generation of lumps, the heat resistance and light resistance, and the resistance to microplasticization. The reason for this is not clear, but it is speculated that the heat resistance and light resistance are improved by the aluminum ion (B) further interacting with the compound (C).

Examples of cinnamic acids include cinnamic acid (cis-cinnamic acid, trans-cinnamic acid, or a mixture thereof), and cinnamic acid derivatives such as cinnamic acid ester and cinnamic acid salt. The cinnamic acid derivative refers to a compound or the like obtained by reacting cinnamic acid. Examples of the cinnamic acid ester include methyl cinnamic acid, ethyl cinnamic acid and the like. Examples of the cinnamic acid salt include sodium cinnamic acid, magnesium cinnamic acid, calcium cinnamic acid and the like. Among them, it is preferable to use cinnamic acid as the cinnamic acid, particularly trans-cinnamic acid from the viewpoint of stability and price. When cinnamic acid is used, a part or all of cinnamic acid may be cinnamic acid salt by coexisting with aluminum ion (B).

The conjugated polyene compound has a structure in which carbon-carbon double bonds and carbon-carbon single bonds are alternately connected, and has a so-called conjugated double bond in which the number of carbon-carbon double bonds is two or more. It is a compound. The conjugated polyene compound may be a conjugated diene having two conjugated double bonds, a conjugated triene having three, or a conjugated polyene having a larger number. Further, the above-mentioned conjugate double bonds may be formed in a plurality of pairs in one molecule without conjugating with each other. For example, a compound having three conjugated triene structures in the same molecule, such as tung oil, is also included in the conjugated polyene compound.

The number of conjugated double bonds of the conjugated polyene compound is preferably 7 or less. Coloring can be reduced by using a conjugated polyene compound having 7 or less conjugated double bonds.

In addition to the conjugated double bond, the conjugated polyene compound includes a carboxy group and a salt thereof, a hydroxyl group, an ester group, a carbonyl group, an ether group, an amino group, an imino group, an amide group, a cyano group, a diazo group, a nitro group and a sulfone group. And other functional groups such as salts thereof, sulfonyl groups, sulfoxide groups, sulfide groups, thiol groups, phosphate groups and salts thereof, phenyl groups, halogen atoms, double bonds, triple bonds and the like.

Examples of the conjugated polyene compound include isoprene, 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-t-butyl-1,3-butadiene, and 1,3-pentadiene. , 2,3-dimethyl-1,3-pentadiene, 2,4-dimethyl-1,3-pentadiene, 3,4-dimethyl-1,3-pentadiene, 3-ethyl-1,3-pentadiene, 2-methyl -1,3-Pentidiene, 3-Methyl-1,3-Pentidiene, 4-Methyl-1,3-Pentidiene, 1,3-Hexadiene, 2,4-Hexadiene, 2,5-dimethyl-2,4-Hexadiene , 1,3-octadiene, 1,3-cyclopentadiene, 1,3-cyclohexadiene, 1-phenyl-1,3-butadiene, 1,4-diphenyl-1,3-butadiene, 1-methoxy-1,3 -Butadiene, 2-methoxy-1,3-butadiene, 1-ethoxy-1,3-butadiene, 2-ethoxy-1,3-butadiene, 2-nitro-1,3-butadiene, chloroprene, 1-chloro-1 , 3-butadiene, 1-bromo-1,3-butadiene, 2-bromo-1,3-butadiene, osimene, piperylene, myrsen, farnesene, sorbic acid, sorbic acid ester, sorbate and other conjugated diene compounds;
Conjugated triene compounds such as 1,3,5-hexatriene, 2,4,6-octatriene-1-carboxylic acid, eleostearic acid, tung oil, cholecalciferol, fulvene, tropone;
Examples thereof include conjugated polyene compounds such as cyclooctatetraene, 2,4,6,8-decatetraene-1-carboxylic acid, retinol and retinoic acid.

The molecular weight of the conjugated polyene compound is usually 1,000 or less, preferably 500 or less, and more preferably 300 or less. When the molecular weight of the conjugated polyene compound is 1,000 or less, the dispersed state of the conjugated polyene compound in EVOH (A) is improved, and the appearance after melt molding is improved.

As the conjugated polyene compound, sorbic acid, sorbic acid ester, sorbate, milsen, and a mixture of two or more of these are preferable, and sorbic acid, sorbate, and a mixture thereof are more preferable. Sorbic acid, sorbic acid salt and mixtures thereof have a high effect of suppressing oxidative deterioration at high temperatures, and are also widely used industrially as food additives, and are therefore preferable from the viewpoint of hygiene and availability.

Compound (C) may be an unsaturated carboxylic acid or a salt thereof. Examples of such a compound include cinnamic acid, sorbic acid, and salts thereof. The unsaturated carboxylic acid has preferably 4 or more and 20 or less carbon atoms, and more preferably 6 or more and 10 or less carbon atoms. Compound (C) may exist in an anionic state.

In the resin composition of the present invention, the lower limit of the content (c) of the compound (C) with respect to EVOH (A) is preferably 1 ppm, more preferably 5 ppm, still more preferably 10 ppm, and even more preferably 30 ppm. By setting the content (c) of the compound (C) to be equal to or higher than the above lower limit, the effect of containing the compound (C) can be particularly sufficiently exhibited. On the other hand, the upper limit of the content (c) is preferably 1,000 ppm with respect to EVOH (A), and may be more preferably 500 ppm. When the content (c) of the compound (C) is not more than the above upper limit, the occurrence of lumps can be further reduced. The content of the compound (C) in the entire resin composition of the present invention is also preferably within the above range. The content (c) is the content (mass) of the compound (C) per 1 g of EVOH (A), and the content (mass) of the compound (C) with respect to the content (mass) of EVOH (A). ).

(Thermoplastic Elastomer (F))
The resin composition of the present invention may further contain a thermoplastic elastomer (F) in order to improve the bending resistance and the like of the resin composition.

The thermoplastic elastomer (F) is not particularly limited, and polyester-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, and the like can be used. These may be one kind or a combination of two or more kinds. Above all, from the viewpoint of improving bending resistance, the thermoplastic elastomer (F) is preferably at least one selected from the group consisting of polystyrene-based thermoplastic elastomers and polyolefin-based thermoplastic elastomers.

The thermoplastic elastomer (F) is preferably a modified thermoplastic elastomer. The modified thermoplastic elastomer is preferably modified with an unsaturated carboxylic acid or a derivative thereof, and the unsaturated carboxylic acid or a derivative thereof is maleic acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride, and the like. Examples thereof include maleic acid monomethyl ester, maleic acid monoethyl ester, maleic acid diethyl ester, and fumaric acid monomethyl ester. Of these, maleic anhydride-modified thermoplastic elastomers are more preferable. When the thermoplastic elastomer (F) is a modified thermoplastic elastomer, the compatibility with EVOH (A) is enhanced, and the gas barrier property, transparency, flexibility and peelability are further improved, which is preferable.

Examples of the polyester-based thermoplastic elastomer (hereinafter, may be referred to as TPEE) include a multi-block copolymer having a polyester as a hard segment in the molecule and a polyether or polyester having a low glass transition temperature (Tg) as a soft segment. Be done. The TPEE can be classified into the following types according to the difference in the molecular structure, and among them, the polyester-polyester type TPEE and the polyester-polyester type TPEE are preferable.
(1) Polyester / polyether type TPEE
Generally, it is a thermoplastic elastomer using aromatic crystalline polyester as a hard segment and polyether as a soft segment.
(2) Polyester / polyester type TPEE
It is a thermoplastic elastomer using aromatic crystalline polyester as a hard segment and aliphatic polyester as a soft segment.
(3) Liquid crystal TPEE
It is a thermoplastic elastomer using rigid liquid crystal molecules as hard segments and aliphatic polyester as soft segments.

Examples of the polyester segment include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; and aliphatic dicarboxylic acids such as succinic acid and adipic acid. Polyester segment composed of a dicarboxylic acid component and an aliphatic diol such as ethylene glycol, 1,2-propylene glycol, 1,4-butanediol; and a diol component such as an alicyclic diol such as cyclohexane-1,4-dimethanol. Can be mentioned. Examples of the polyether segment include aliphatic polyether segments such as polyethylene glycol, polypropylene glycol and polybutylene glycol. The polyester-based thermoplastic elastomer is preferably a modified polyester-based thermoplastic elastomer, and more preferably a maleic anhydride-based polyester-based thermoplastic elastomer.

The polystyrene-based thermoplastic elastomer is not particularly limited, but usually includes a styrene monomer polymer block (Hb) as a hard segment and a conjugated diene compound polymer block or a hydrogenated block (Sb) thereof as a soft segment. The structure of this styrene-based thermoplastic elastomer is represented by a diblock structure represented by Hb-Sb, a triblock structure represented by Hb-Sb-Hb or Sb-Hb-Sb, and a structure represented by Hb-Sb-Hb-Sb. It may be a tetrablock structure to be formed, or a polyblock structure in which a total of 5 or more Hb and Sb are linearly bonded.

The styrene-based monomer used in the styrene monomer polymer block (Hb) is not particularly limited, and examples thereof include styrene and its derivatives. Specifically, styrene, α-methylstyrene, 2-methylstyrene, 4-methylstyrene, 4-propylstyrene, 4-t-butylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4- Styrenes such as benzyl styrene, 4- (phenylbutyl) styrene, 2,4,6-trimethylstyrene, monofluorostyrene, difluorostyrene, monochlorostyrene, dichlorostyrene, methoxystyrene, t-butoxystyrene; 1-vinylnaphthalene, 2-Vinyl group-containing aromatic compounds such as vinylnaphthalene such as vinylnaphthalene; Examples thereof include vinylene group-containing aromatic compounds such as inden and acetylene. Of these, styrene is preferable. The styrene-based monomer may be only one kind or two or more kinds.

The conjugated diene compound used for the conjugated diene compound polymer block or the hydrogenated block (Sb) thereof is also not particularly limited, and examples thereof include butadiene, isoprene, 2,3-dimethylbutadiene, pentadiene, and hexadiene. can. Of these, butadiene is preferable. The conjugated diene compound may be only one kind or two or more kinds. Further, other co-monomers such as ethylene, propylene, butylene and styrene can be copolymerized. Further, the conjugated diene compound polymer block may be a hydrogenated body which is partially or completely hydrogenated.

Specific examples of the polystyrene-based thermoplastic elastomer include styrene-isopregen block copolymer (SI), styrene-butadiene diblock copolymer (SB), styrene-isoprene-styrene triblock copolymer (SIS), and styrene. Examples thereof include a butadiene / isoprene-styrene triblock copolymer (SB / IS), a styrene-butadiene-styrene triblock copolymer (SBS), and a hydrogenated product thereof. Among them, a hydrogenated product of a styrene-isopregen block copolymer (SEP), a hydrogenated product of a styrene-butadiene diblock copolymer (SEB), and a hydrogenated product of a styrene-isoprene-styrene triblock copolymer (SEPS). ), A hydrogenated product of a styrene-butadiene / isoprene-styrene triblock copolymer (SEEPS), and a hydrogenated product of a styrene-butadiene-styrene triblock copolymer (SEBS). Is preferable. The polystyrene-based thermoplastic elastomer is preferably a modified polystyrene-based thermoplastic elastomer, and more preferably an anhydrous maleic acid-modified polystyrene-based thermoplastic elastomer.

The polyolefin-based thermoplastic elastomer includes a thermoplastic elastomer having a polyolefin block such as polypropylene or polyethylene as a hard segment and a rubber block such as an ethylene-propylene-diene copolymer as a soft segment. The thermoplastic elastomer includes a blend type and an implant type. Examples of the modified polyolefin-based thermoplastic elastomer include maleic anhydride-modified ethylene-butene-1 copolymer, maleic anhydride-modified ethylene-propylene copolymer, butyl halide rubber, modified polypropylene, and modified polyethylene. You can also. The polyolefin-based thermoplastic elastomer is preferably a modified polyolefin-based thermoplastic elastomer, and more preferably an anhydrous maleic acid-modified polyolefin-based thermoplastic elastomer.

The lower limit of the mass ratio (F / A) of the thermoplastic elastomer (F) to EVOH (A) in the resin composition of the present invention is preferably 5/95, more preferably 8/92, still more preferably 12/88. 15/85 or 25/75 may be even more preferred. By setting the mass ratio (F / A) to the above lower limit or higher, bending resistance and the like can be improved. On the other hand, as the upper limit of this mass ratio (F / A), 35/65 is preferable, 30/70 is more preferable, and 25/75 may be further preferable. By setting the mass ratio (F / A) to the above upper limit or less, the gas barrier property and the like can be further improved.

(Phase separation structure)
In the resin composition of the present invention, it is preferable that the particles of the thermoplastic elastomer (F) are dispersed in the matrix of EVOH (A). That is, it is preferable that the resin composition of the present invention has a sea-island structure, the sea phase is mainly composed of EVOH (A), and the island phase is mainly composed of a thermoplastic elastomer (F). As described above, since the sea phase is mainly composed of EVOH (A), the flexibility is improved while maintaining the gas barrier property.

When the resin composition of the present invention has a sea-island structure, the sea phase is mainly composed of EVOH (A), and the island phase is mainly composed of a thermoplastic elastomer (F), it is thermoplastic from the viewpoint of improving transparency. The average particle size of the island phase made of the elastomer (F) is preferably 4.5 μm or less, more preferably 3.5 μm or less, further preferably 3.0 μm or less, particularly preferably 2.5 μm or less, and most preferably 2.0 μm or less. preferable. The average particle size of the thermoplastic elastomer (F) may be 0.1 μm or more. It is preferable that the average particle size of the island phase made of the thermoplastic elastomer (F) is in the above range because the flexibility is improved and the peelability is further improved while maintaining the gas barrier property and transparency. The average particle size of the thermoplastic elastomer (F) can be adjusted by adjusting the kneading strength and the composition ratio of EVOH (A) and the thermoplastic elastomer (F).

In the resin composition of the present invention, the difference in refractive index between EVOH (A) and the thermoplastic elastomer (F) is preferably 0.05 or less, more preferably 0.04 or less, still more preferably 0.03 or less. The difference in refractive index may be 0.005 or more. When the difference in refractive index is in the above range, the transparency of the resin composition of the present invention becomes better, which is preferable.

(Antioxidant (G))
The resin composition of the present invention further contains an antioxidant (G) in order to improve oxidative deterioration and the like of the resin composition. When the resin composition further contains an antioxidant, it is possible to suppress the occurrence of cracks in a molded body such as a pipe formed from the resin composition, and also improve heat resistance and light resistance, resistance to microplasticization, and the like. Tend to do.

The antioxidant (G) is a compound having an antioxidant ability. The melting point of the antioxidant (G) is not necessarily limited, but is preferably 170 ° C. or lower. When the melting point of the antioxidant (G) is 170 ° C. or lower, it is easy to melt in the extruder when the resin composition is produced by melt mixing. Therefore, it is possible to prevent the antioxidant (G) from being localized in the resin composition and coloring the high-concentration portion. Further, the melting point of the antioxidant (G) is preferably 50 ° C. or higher, more preferably 100 ° C. or higher. When the melting point of the antioxidant (G) is 50 ° C. or higher, it is possible to prevent the antioxidant from bleeding out to the surface of the obtained molded product (pipe or the like) and deteriorating the appearance.

The molecular weight of the antioxidant (G) is preferably 300 or more. When the molecular weight of the antioxidant (G) is 300 or more, when the molded product is obtained from the resin composition of the present invention, the antioxidant bleeds out on the surface and the appearance of the molded product is deteriorated. It can be suppressed and the thermal stability of the resin composition is enhanced. The molecular weight is more preferably 400 or more, and particularly preferably 500 or more. On the other hand, the upper limit of the molecular weight of the antioxidant (G) is not particularly limited, but from the viewpoint of dispersibility, it is preferably 8000 or less, more preferably 6000 or less, further preferably 4000 or less, and particularly preferably 2000 or less.

As the antioxidant (G), a compound having a hindered phenol group is preferably used. While the compound having a hindered phenol group has excellent thermal stability by itself, it has the ability to capture oxygen radicals that cause oxidative deterioration, and when blended in a resin composition as an antioxidant, it causes oxidative deterioration. It has an excellent preventive effect.

As the compound having a hindered phenol group, a commercially available compound can be used, and examples thereof include the following products.
(1) "IRGANOX 1010" manufactured by BASF, melting point 110-125 ° C., molecular weight 1178, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]
(2) BASF's "IRGANOX 1076": melting point 50-55 ° C., molecular weight 531 and octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (3) BASF's "IRGANOX 1098" : Melting point 156-161 ° C., molecular weight 637, N, N'-(hexane-1,6-diyl) bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionamide]
(4) BASF's "IRGANOX 245": melting point 76-79 ° C., molecular weight 587, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate]
(5) "IRGANOX 259" manufactured by BASF: Melting point 104-108 ° C., molecular weight 639, 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]
(6) "Sumilizer MDP-s" manufactured by Sumitomo Chemical Co., Ltd .: Melting point about 128 ° C., molecular weight 341, 2,2'-methylene-bis (4-methyl-6-tert-butylphenol)
(7) "Sumilizer GM" manufactured by Sumitomo Chemical Industry Co., Ltd .: melting point about 128 ° C., molecular weight 395, 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methyl Phenyl acrylate (8) "Sumilizer GA-80" manufactured by Sumitomo Chemical Industry Co., Ltd .: melting point about 110 ° C., molecular weight 741, 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5- Methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane

As the antioxidant (G), a compound having a hindered amine group is also preferably used. When a compound having a hindered amine group is blended in a resin composition as an antioxidant (G), it not only prevents thermal deterioration of EVOH (A) but also captures aldehydes generated by thermal decomposition of EVOH (A). By reducing the generation of decomposition gas, it is possible to suppress the generation of voids or bubbles during molding. Further, by capturing the aldehyde, when the resin composition of the present invention is used as a food packaging container, the point that the odor due to the aldehyde impairs the taste of the contents is also improved.

A preferred compound having a hindered amine group is a piperidine derivative, and a 2,2,6,6-tetraalkylpiperidine derivative having a substituent at the 4-position is particularly preferable. Examples of the substituent at the 4-position include a carboxyl group, an alkoxy group and an alkylamino group.

Further, although an alkyl group may be substituted at the N-position of the hindered amine group, it is preferable to use one to which a hydrogen atom is bonded because of its excellent thermal stabilization effect.

As the compound having a hindered amine group, a commercially available compound can be used, and examples thereof include the following products.
(9) BASF's "TINUVIN 770": melting point 81-85 ° C, molecular weight 481, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (10) BASF's "TINUVIN 765": liquid Compound, molecular weight 509, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (mixture)
(11) BASF "TINUVIN 622LD": melting point 55-70 ° C., molecular weight 3100-4000, dimethyl 1- (2-hydroxyethyl) succinate-4-hydroxy-2,2,6,6-tetramethylpiperidine Polycondensate (12) BASF "CHIMASORB 119FL": melting point 130-140 ° C., molecular weight 2000 or more, N, N'-bis (3-aminopropyl) ethylenediamine 2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate (13) BASF "CHIMASTORB 944LD": melting point 100-135 ° C., Molecular weight 2000-3100, poly [[6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl] (2,2,6,6-tetramethyl] -4-Piperidyl) imino] Hexamethylene (2,2,6,6-tetramethyl-4-pipeziryl) imino]]
(14) BASF's "TINUVIN 144": melting point 146-150 ° C., molecular weight 685, bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-) Dimethylethyl) -4-Hydrikyphenyl] Methyl] Butylmalonate (15) BASF's "UVINUL 4050H": Melting point 157 ° C., molecular weight 450, N, N'-1,6-hexanediylbis {N- (2) , 2,6,6-tetramethyl-4-piperidinyl) -formamide}
(16) "UVINUL 5050H" manufactured by BASF, a compound having a melting point of 104-112 ° C., a molecular weight of about 3500, and the following structural formula.

These compounds having a hindered phenol group or a hindered amine group may be used alone or in combination of two or more.

The lower limit of the content (g) of the antioxidant (G) with respect to EVOH (A) is 0.01% by mass, preferably 0.1% by mass, and more preferably 0.3% by mass. The upper limit of the content (g) of the antioxidant (G) is 5% by mass, preferably 3% by mass, and more preferably 1% by mass. When the content (g) of the antioxidant (G) is in the above range, the antioxidant (G) is well dispersed, and when a molded product is obtained from the resin composition of the present invention, the appearance is excellent and It tends to exhibit good oxidative deterioration resistance, heat resistance, and the like.

(Other ingredients)
The resin composition of the present invention can be used for resins other than EVOH (A) and thermoplastic elastomer (F), metal ions other than aluminum ions (B), and acids (compound (C)) as long as the effects of the present invention are not impaired. (Except applicable), boron compounds, plasticizers, fillers, blocking inhibitors, lubricants, stabilizers, surfactants, coloring agents, UV absorbers, antistatic agents, desiccants, cross-linking agents, reinforcing materials, etc. It may have the component of. Above all, from the viewpoint of thermal stability and adhesion to other resins, one or more of metal ions other than aluminum ion (B), acid (excluding those corresponding to compound (C)) and boron compound. It is preferable to include.

As the metal ion other than the aluminum ion (B), an alkali metal ion is preferable because the interlayer adhesiveness can be further enhanced when the resin composition of the present invention is used as a laminated body (multilayer structure). These metal ions may exist in the salt state.

When the resin composition of the present invention contains such metal ions, the content thereof is preferably 1 ppm or more, more preferably 5 ppm or more, further preferably 10 ppm or more, still more preferably 20 ppm or more, and 40 ppm or more with respect to the resin composition. Is particularly preferable. The content of the metal ion other than the aluminum ion (B) is preferably 3,000 ppm or less, more preferably 1,000 ppm or less, further preferably 500 ppm or less, and particularly preferably 300 ppm or less with respect to the resin composition. When the content of the metal ion other than the aluminum ion (B) is in the above range, the interlayer adhesiveness of the laminate is kept good, and the thermal stability when the laminate is recovered and recycled is good. Will tend to be.

As the acid (excluding those corresponding to compound (C)), carboxylic acid or phosphoric acid is preferable from the viewpoint of enhancing thermal stability during melt molding. Examples of the carboxylic acid include formic acid, acetic acid, butyric acid, and lactic acid. As the carboxylic acid, a carboxylic acid having 4 or less carbon atoms or a saturated carboxylic acid is preferable, and acetic acid is more preferable. The acid may be present in the form of a salt or anion.

When the resin composition of the present invention contains a carboxylic acid, the content of the carboxylic acid is preferably 1 ppm or more, more preferably 10 ppm or more, still more preferably 50 ppm or more, based on the resin composition. The content of the carboxylic acid is preferably 10,000 ppm or less, more preferably 1,000 ppm or less, still more preferably 500 ppm or less. When the resin composition of the present invention contains phosphoric acid, the content of phosphoric acid is preferably 1 ppm or more, more preferably 10 ppm or more, still more preferably 30 ppm or more in terms of phosphoric acid roots with respect to the resin composition. The content of the phosphoric acid compound is preferably 10,000 ppm or less, more preferably 1,000 ppm or less, and even more preferably 300 ppm or less. When the resin composition of the present invention contains carboxylic acid or phosphoric acid within the above range, the thermal stability during melt molding tends to be good.

Examples of the boron compound include boric acid, borate ester, borate, and boron hydride.

When the resin composition of the present invention contains a boron compound, the content of the boron compound is preferably 1 ppm or more, more preferably 10 ppm or more, based on the resin composition or EVOH (A). The content of the boron compound is preferably 2,000 ppm or less, more preferably 1000 ppm or less. When the resin composition of the present invention contains a boron compound within the above range, the thermal stability during melt molding tends to be good.

The method for incorporating each of these components into the resin composition of the present invention is not particularly limited, and can be carried out by a conventionally known method.

EVOH (A), aluminum ion (B), compound (C), thermoplastic elastomer (F), antioxidant (G), metal ion other than aluminum ion (B), acid (compound) in the resin composition of the present invention. (Excluding those corresponding to (C)) and the upper limit of the content of components other than the boron compound may be preferably 10% by mass, 1% by mass, 0.1% by mass, 0.01% by mass or 0.001. In some cases,% by weight is preferable.

(Melt flow rate)
The lower limit of the melt flow rate at a temperature of 210 ° C. and a load of 2,160 g of the resin composition of the present invention is preferably 1.0 g / 10 minutes, more preferably 2.0 g / 10 minutes. On the other hand, the upper limit of the melt flow rate is preferably 30 g / 10 minutes, more preferably 20 g / 10 minutes, still more preferably 10 g / 10 minutes. When the melt flow rate of the resin composition of the present invention is within the above range, melt moldability, processability and the like are improved.

(Manufacturing method of resin composition)
As a method for producing a resin composition of the present invention, a method of producing a resin composition containing EVOH (A) and aluminum ions (B) and then mixing the resin composition with an antioxidant (G). Examples thereof include a method of collectively mixing EVOH (A), aluminum ion (B) and an antioxidant (G).

As a method for producing a resin composition containing EVOH (A) and aluminum ion (B), for example, 1) a porous precipitate of EVOH (A) having a water content of 20 to 80% by mass contains an aluminum salt or the like. A method of contacting EVOH (A) with an aluminum salt or the like and then drying it. 2) A uniform solution of EVOH (A) (water / alcohol solution, etc.) contains an aluminum salt or the like. After that, it is extruded into a coagulating liquid in the form of strands, and then the obtained strands are cut into pellets and further dried. 3) A method of collectively dry-blending EVOH (A) and an aluminum salt or the like. 4) A method in which EVOH (A) and an aluminum salt or the like are collectively dry-blended and then melt-kneaded with an extruder or the like. 5) After obtaining an ethylene-vinyl ester copolymer during the production of EVOH (A). , A method of adding an aluminum salt or the like. In order to obtain the effect of the present invention more remarkably, the methods 1), 2) and 5) are preferable because the dispersibility of the aluminum ion (B) is excellent.

In the above methods 1) and 2), after an aluminum salt or the like is added, and in the method 5), after obtaining an ethylene-vinyl ester copolymer, after undergoing a saponification step and a washing step. , Usually drying is done. As such a drying method, various drying methods can be adopted. For example, fluid drying in which the substantially pellet-shaped resin composition is mechanically or while being stirred and dispersed by hot air, and the substantially pellet-shaped resin composition exerts dynamic actions such as stirring and dispersion. Examples include static drying performed without being given. Examples of the dryer for fluidized drying include a cylindrical / groove type stirring dryer, a circular tube dryer, a rotary dryer, a fluidized bed dryer, a vibrating fluidized bed dryer, and a conical rotary dryer. Examples of the dryer for static drying include a batch box type dryer as the material static type, and a band dryer, a tunnel dryer, a vertical type dryer and the like as the material transfer type. A combination of fluid drying and static drying may be performed.

Air or an inert gas (nitrogen gas, helium gas, argon gas, etc.) is used as the heating gas used during the drying treatment, and the temperature of the heating gas is 40 to 150 ° C. for productivity and EVOH (A). ) Is preferable in terms of suppressing thermal deterioration. The drying treatment time depends on the water content of the resin composition and the treatment amount thereof, but is usually preferably about 15 minutes to 72 hours in terms of productivity and prevention of thermal deterioration of EVOH (A).

Further, as the method of 4) above, there is a method of melt-kneading with, for example, a single-screw or twin-screw extruder. The melt-kneading temperature is usually 150 to 300 ° C, preferably 170 to 250 ° C.

As a method of mixing the resin composition containing EVOH (A) and aluminum ion (B) with the antioxidant (G), a known method such as melt kneading can be used. At this time, other components may be added and melt-kneaded or the like. As a method of collectively mixing the EVOH (A), the aluminum ion (B) and the antioxidant (G), in the method of producing the above mixture 3), 4) or 5), the antioxidant is added together with the aluminum salt. Examples thereof include a method of dry blending or adding the agent (G). At this time, similarly, other components may be dry-blended or added.

The resin composition of the present invention can be processed into any form such as pellets and powders and used as a molding material, and is usually in a dry state. The upper limit of the water content to the total solid content of the resin composition of the present invention may be preferably 1% by mass, more preferably 0.1% by mass or 0.01% by mass. When the resin composition of the present invention is in a dry state, good melt moldability and the like can be exhibited.

<Molded body>
The resin composition of the present invention can be molded into a molded product such as a film, a sheet, a tube, a bag, or a container by melt molding or the like. That is, the molded product of the present invention is a molded product molded from the resin composition of the present invention. The molded product of the present invention may be formed only from the resin composition of the present invention, or may have a portion formed from another material. For example, a laminated body (multilayer structure) described later is also a form of a molded body.

The molded product of the present invention suppresses the generation of lumps during melt molding, has sufficient heat and light resistance, is difficult to be microplasticized after disposal, and has sufficient above-mentioned characteristics as compared with those using the same EVOH. Has been improved. Further, the molded product of the present invention is less likely to cause cracks due to oxidative deterioration in the EVOH layer even when used at a high temperature for a long period of time. Therefore, the resin composition of the present invention is particularly useful as a melt molding material.

Examples of the method for melt molding the resin composition of the present invention include extrusion molding, cast molding, inflation extrusion molding, blow molding, melt spinning, injection molding, injection blow molding and the like. The melt molding temperature varies depending on the melting point of EVOH (A) and the like, but is preferably about 150 to 270 ° C. These compacts can also be crushed and remolded for reuse. It is also possible to stretch a film, a sheet or the like uniaxially or biaxially.

<Laminated body (multilayer structure)>
The laminate of the present invention has at least one layer made of the resin composition of the present invention. The laminate usually has a layer made of the resin composition of the present invention and a layer made of other components. The lower limit of the number of layers of the laminated body of the present invention is, for example, 2, may be 3, and may be 4. The upper limit of the number of layers is, for example, 1,000, may be 100, or may be 20.

Examples of the layer composed of the above other components include layers composed of thermoplastic resins other than EVOH (A), paper, woven fabrics, non-woven fabrics, metal cotton strips, wood surfaces, metals and the like, and among them, other layers. A thermoplastic resin layer is preferred. The layer structure of the laminate of the present invention is not particularly limited, and when the layer made of the resin composition of the present invention is represented by E, the adhesive layer is represented by Ad, and the layer obtained from another thermoplastic resin is represented by T, T / E / Structures such as T, E / Ad / T, T / Ad / E / Ad / T and the like can be mentioned. Each of these layers may be single-layered or multi-layered.

The method for producing the laminate of the present invention is not particularly limited, and for example, a method of melt-extruding a thermoplastic resin into a molded product (film, sheet, etc.) obtained from the resin composition of the present invention, and the resin composition of the present invention. A method of co-extruding with another thermoplastic resin, a method of co-injecting the resin composition of the present invention with another thermoplastic resin, a barrier layer obtained from the resin composition of the present invention, and another thermoplastic resin layer. Examples thereof include a method of laminating with a known adhesive such as an isocyanate compound and a polyester-based compound.

Other thermoplastic resins described above include linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, polypropylene, and propylene-α-. Olefin (α-olefin with 4 to 20 carbon atoms) copolymer, olefin alone or copolymer such as polybutene and polypentene; polyester polyester elastomer such as polyethylene terephthalate, polyamide such as nylon-6 and nylon-66, polystyrene , Polyvinyl chloride, polyvinylidene chloride, acrylic resin, vinyl ester resin, polyurethane elastomer, polycarbonate, chlorinated polyethylene, chlorinated polypropylene and the like. Of these, polypropylene, polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyamide, polystyrene and polyester are preferably used.

The adhesive layer may have adhesiveness to the layer of the resin composition of the present invention and the layer of another thermoplastic resin, and an adhesive resin containing a carboxylic acid-modified polyolefin is preferable. As the carboxylic acid-modified polyolefin, a modified olefin-based polymer containing a carboxyl group obtained by chemically bonding an ethylenically unsaturated carboxylic acid, an ester thereof or an anhydride thereof to an olefin-based polymer is preferably used. Here, the olefin-based polymer means a polyolefin such as polyethylene, linear low-density polyethylene, polypropylene, or polybutene, or a copolymer of an olefin and another monomer. Of these, linear low-density polyethylene, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid ethyl ester copolymer are preferable, and linear low-density polyethylene and ethylene-vinyl acetate copolymer are particularly preferable.

When the laminate of the present invention is a multilayer film or sheet, the average thickness is not particularly limited, and the lower limit may be, for example, 1 μm, 5 μm or 10 μm. On the other hand, the upper limit of the average thickness may be, for example, 3 mm, 1 mm, 300 μm or 100 μm. The shape of the laminated body is not particularly limited as long as it has a laminated structure. A multi-layered thermoformed container, a multi-layered blow-molded container, a multi-layered pipe, a vapor-deposited film, and the like, which will be described later, are also included in the form of the laminated body.

The molded body and the laminated body of the present invention suppress the generation of lumps during melt molding, have sufficient heat and light resistance, and are difficult to be microplasticized after disposal, and each of the above is compared with the one using the same EVOH. The characteristics are sufficiently improved. Further, even when the EVOH layer is used at a high temperature for a long period of time, cracks due to oxidative deterioration are unlikely to occur in the EVOH layer. Therefore, it is suitable for daily necessities, packaging materials, machine parts and the like used outdoors. Examples of applications in which the characteristics of the molded body and the like are particularly effectively exhibited include food and drink packaging materials, container packing materials, films, agricultural films, geomembranes, medical infusion bag materials, high-pressure tank materials, and the like. Gasoline tank material, fuel container, tube material for tires, cushion material for shoes, inner bag material for bag-in-box, tank material for organic liquid storage, pipe (pipe material for organic liquid transportation, hot water pipe material for heating (for floor heating) (Hot water pipe material, etc.), etc.), resin wallpaper, plant medium, etc. can be mentioned. In particular, the molded body and laminated body of the present invention are preferably used as films, pipes, agricultural films, plant media and geomembranes that are used outdoors and are easily deteriorated by heat or light.

<Pipe>
The pipe of the present invention has a layer made of the resin composition of the present invention. The pipe has sufficient heat resistance and light resistance, is difficult to be microplasticized after disposal, and has sufficient above-mentioned characteristics as compared with the pipe using the same EVOH. It has been improved.

Further, in the layer made of the resin composition of the present invention possessed by the pipe, the resin composition contains a predetermined amount of aluminum ions (B) and an antioxidant (G). As a result, the heat resistance, the oxidation deterioration resistance, and the like are particularly enhanced, so that the generation of cracks and the like are suppressed, and the product can be used for a long period of time.

The pipe may be a single-layer pipe or a multi-layer pipe. When the pipe is a multi-layer pipe, the layer structure may be an example of a layer structure similar to the above-mentioned laminated body of the present invention. For example, in the layer structure of the multilayer pipe, when the layer made of the resin composition of the present invention is represented by E, the adhesive layer is represented by Ad, and the layer obtained from another thermoplastic resin is represented by T, T / E / T, E / Examples thereof include structures such as Ad / T and T / Ad / E / Ad / T. Each of these layers may be single-layered or multi-layered. Specific examples of the resin used for the adhesive layer and the layer obtained from other thermoplastic resins include the same resins as those used for these layers in the laminate of the present invention. Further, the method for producing the pipe is not particularly limited, and various molding methods exemplified as a method for melt molding the resin composition of the present invention can be adopted.

The use of the pipe is not particularly limited, and it can be used, for example, as a hot water circulation pipe, a heat insulating multi-layer pipe, a fuel pipe, a gas pipe, or the like.

When the pipe of the present invention is a multi-layer pipe and this multi-layer pipe is used as a pipe for hot water circulation, a three-layer structure of T / Ad / E having the layer made of the above resin composition as the outermost layer is generally used. Will be adopted. By adding the coextrusion coating equipment of the resin composition of the present invention and the adhesive resin to the existing single-layer pipe production line such as cross-linked polyolefin, it can be easily diverted to the multi-layer pipe production line. This is because many pipe manufacturers have adopted this configuration.

It is effective to provide a polyolefin layer or the like on both sides of the layer made of the resin composition of the present invention and use the resin composition layer as an intermediate layer to prevent scratches on the resin composition layer. However, when the multi-layer pipe is used as a hot water circulation pipe such as a floor heating pipe, it is usually buried under the floor, so the risk of damage to the layer made of the resin composition of the present invention due to physical impact is compared. Since it is small in size, it is desirable to arrange the resin composition layer on the outermost layer from the viewpoint of gas barrier properties. The gas barrier property of EVOH (A) shows a large humidity dependence, and the barrier property decreases under high humidity conditions. Therefore, by arranging the layer made of the resin composition of the present invention on the outermost layer, mainly EVOH (A) ), The layer made of the resin composition of the present invention is located at the farthest place from the inner surface of the pipe in contact with water, which is the most advantageous layer structure in terms of the barrier performance of the multi-layer pipe. On the other hand, when the EVOH layer is generally arranged on the outermost layer, it is easily affected by oxidative deterioration because it comes into direct contact with air. In such an environment, by arranging a layer made of the resin composition of the present invention, which is resistant to oxidative deterioration even at high temperatures, as the outermost layer, a multilayer layer having good barrier properties and reducing the occurrence of cracks due to oxidative deterioration. The effect of the present invention of providing a pipe is more effectively exhibited.

Further, when the pipe of the present invention is used for a heat insulating multi-layer pipe for district heating and cooling, etc., it has a three-layer structure of T / Ad / E in which the layer made of the above resin composition is arranged inside the thermoplastic resin layer (hereinafter referred to as “)”. (Sometimes abbreviated as laminate 1), or a five-layer structure of T / Ad / E / Ad / T from the viewpoint of preventing damage to the resin composition layer (hereinafter, may be abbreviated as laminate 2). It is preferable to have.

The configuration of the heat insulating multilayer pipe for district heating and cooling is not particularly limited, but for example, the above-mentioned layer having an inner pipe, a heat insulating foam layer covering the circumference of the inner pipe, and a layer made of the resin composition of the present invention as an outer layer. It is preferable that the bodies 1 or 2 are arranged in this order.

The type (material), shape and size of the pipe used for the inner pipe are not particularly limited as long as they can transport a heat medium such as gas or liquid, and the type of heat medium and the use and usage form of the piping material are not particularly limited. It can be appropriately selected according to the above. Specifically, from metals such as steel, stainless steel, and aluminum, polyolefins (polyethylene, cross-linked polyethylene (PEX), polypropylene, poly1-butene, poly4-methyl-1-pentene, etc.), and the resin composition of the present invention. Examples thereof include the above-mentioned laminate 1 or 2 having a layer to be formed, and among these, cross-linked polyethylene (PEX) is preferably used.

Polyurethane foam, polyethylene foam, polystyrene foam, phenol foam, and polyisocyanurate foam can be used as the heat insulating foam constituting the heat insulating foam layer, and polyurethane foam is preferably used from the viewpoint of improving heat insulating performance.

Freon gas, various alternative fluorocarbons, water, hydrocarbons chloride, hydrocarbons, carbon dioxide, etc. are used as foaming agents for heat insulating foams, but hydrocarbons, specifically n-, are used from the viewpoint of foaming effect and environmental impact. Pentane and cyclopentane are preferably used.

As a method for manufacturing a heat insulating multi-layer pipe, for example, an inner pipe for transporting a heat medium is placed in a pipe-shaped outer layer, the inner pipe is fixed with a spacer to form a double pipe, and then a gap between the inner pipe and the outer layer is formed. Examples thereof include a method of injecting various foam stock solutions into the foam to foam and solidify. The material of the spacer is not particularly limited, but polyethylene or polyurethane is preferable in order to reduce damage to the inner tube and the outer layer due to the spacer.

When the pipe of the present invention is used for a fuel pipe, it is more preferable that the layer made of the resin composition of the present invention further contains the thermoplastic elastomer (F). By containing the thermoplastic elastomer (F), the crack resistance of the pipe and the like are further enhanced.

When used in fuel pipes, the innermost layer is formed to be conductive. To that end, the innermost thermoplastic resin is mixed with a conductive additive known per se, such as carbon black or graphite fiber.

<Manufacturing method of pipes, etc.>
Hereinafter, a method for manufacturing a multilayer pipe will be described as an example of a pipe, but a part or all of this manufacturing method can also be applied to a method for manufacturing another molded product (film, sheet, etc.). The multilayer pipe can be produced by coextruding the resin composition of the present invention and the adhesive resin on a single-layer pipe such as a crosslinked polyolefin as described above. When performing coextrusion coating of the resin composition of the present invention and the adhesive resin on a single-layer pipe, simply coat the single-layer pipe with a film in which the resin composition of the present invention and the adhesive resin are melted. However, the adhesive force between the single-layer pipe and the coat layer may be insufficient, and the coat layer may peel off during long-term use and lose the gas barrier property. As a countermeasure, it is effective to perform frame treatment and / or corona discharge treatment on the surface of the pipe to be coated before coating.

As another multi-layer molding method for manufacturing multi-layer pipes, a number of extruders corresponding to the types of resin layers are used, and simultaneous extrusion molding is performed in a layered state in which the flows of the melted resin are overlapped in the extruder. There is a method of carrying out by so-called coextrusion molding. Further, a multi-layer molding method such as dry lamination can also be adopted.

The method for manufacturing a multilayer pipe may include a step of cooling with water at 10 to 70 ° C. immediately after molding. That is, it is desirable to solidify the resin composition layer by cooling with water at 10 to 70 ° C. after melt molding and before the layer made of the resin composition of the present invention solidifies. If the temperature of the cooling water is too low, cracks due to strain are likely to occur in the layer made of the resin composition of the present invention at the bent portion when the multilayer pipe is bent in the subsequent secondary processing step. The details of the cause of the tendency for cracks to occur due to strain are not clear, but it is presumed that the residual stress in the molded product has an effect. From this viewpoint, the temperature of the cooling water is more preferably 15 ° C. or higher, further preferably 20 ° C. or higher. On the other hand, even if the temperature of the cooling water is too high, cracks due to strain are likely to occur in the layer made of the resin composition of the present invention at the bent portion during the secondary processing. The details of this cause have not been fully elucidated, but it is presumed that the crystallinity of the layer made of the resin composition of the present invention becomes too large. From this viewpoint, the temperature of the cooling water is more preferably 60 ° C. or lower, further preferably 50 ° C. or lower.

Various molded bodies can be obtained by secondary processing the multi-layer pipe obtained by the above method. The secondary processing method is not particularly limited, and a known secondary processing method can be appropriately used. For example, in a state where the multilayer pipe is heated to 80 to 160 ° C. and then deformed into a desired shape, 1 A method of processing by fixing for 2 minutes to 2 hours can be mentioned.

Further, even when the pipe of the present invention is a single-layer pipe, it can be produced by the above-mentioned known molding method as a method for melt-molding the resin composition of the present invention.

Hereinafter, the present invention will be specifically described with reference to Examples and the like, but the present invention is not limited to these Examples. The methods of measurement, calculation and evaluation were as follows.

<Quantitative (NMR method) measurement conditions for the primary structure of EVOH>
Device name: JEOL Ltd. Superconducting nuclear magnetic resonance device ECZ-600
Observation frequency: 600MHz (1H)
(1) Solvent: Deuterated dimethyl sulfoxide (DMSO-d ₆ ) Polymer concentration: 5% by mass Measurement temperature: 25 ° C, 80 ° C
Flip angle: 30 ° Total number of times: 256s
Internal standard: Tetramethylsilane (TMS)
( ₂ ) Solvent: Heavy water (D2 O) + Deuterated methanol (MeOD) (mass ratio 4/6) Polymer concentration: 5% by mass Measurement temperature: 80 ° C.
Flip angle: 30 ° Total number of times: 1024s
Internal standard: Tetramethylsilane (TMS)

<Quantification of ethylene unit content, saponification degree, terminal carboxylic acid unit content and terminal lactone ring unit content>
The ethylene unit content (Et Cont.), Kenka degree (SP), terminal carboxylic acid unit content (α) and terminal lactone ring unit content (β) of EVOH are ¹ H-NMR measurement (DMSO-d ₆ solvent). : Measurement results at 25 ° C and 80 ° C, measurement results with D2O ₊ MeOD solvent) were calculated by the following formula. The chemical shift value was based on the peak of TMS of 0 ppm. Further, in the formula, VAc, VAL and Et represent vinyl acetate unit, vinyl alcohol unit and ethylene unit, respectively.
I1, I3: Integral value of methylene hydrogen of 0.4 to 2.35 ppm (I1: DMSO-d ₆ measured value at 25 ° C, I3: measured value at DMSO-d ₆ 80 ° C)
I9 :: Integral value of methylene hydrogen of 0.4 to 2.8 ppm (measured value with D ₂ O + MeOD solvent)
I2: Integral value of methine hydrogen in vinyl alcohol unit of 3.4 to 4.0 ppm (methine hydrogen of vinyl alcohol on both sides of the same unit) (measured value at DMSO-d ₆₂₅ ° C)
I4: Integrated value of methine hydrogen in vinyl alcohol unit of 3.15 to 3.45 ppm (methine hydrogen of vinyl alcohol on both sides of the same unit) (measured value at DMSO-d ₆₈₀ ° C)
I5: Integral value derived from hydrogen of the terminal methyl group in vinyl acetate unit (measured value at DMSO-d ₆₈₀ ° C.)
I6: Integral value around 1.8 to 1.85 (measured value at DMSO-d ₆₈₀ ° C)
I7: Integral value derived from hydrogen of the methyl group in the -CH (OH) CH ₃ group present at the polymer terminal of EVOH (measured value at DMSO-d ₆₈₀ ° C.)
I8: Integral value derived from hydrogen of the methyl group in -CH ₂ CH ₃ groups present at the polymer terminal of EVOH (measured value at DMSO-d ₆₈₀ ° C.)
I10: Integral value around 0.8 to 0.95 (measured value with D ₂ O + MeOD solvent)
I11: Integral value derived from hydrogen of CH ₂ unit adjacent to the carbonyl group of terminal lactone ring unit (measured value with D ₂ O + MeOD solvent)
I12: Integral value derived from the linear COOH group of the terminal carboxylic acid group (measured value with D ₂ O + MeOD solvent)
I13, I14: Integral value derived from carboxylate of terminal carboxylic acid units (measured value with D2O ₊ MeOD solvent)
The determined ethylene unit content (Et Cont.), Terminal carboxylic acid unit content (α) and terminal lactone ring unit content (β) are all total amounts of ethylene unit, vinyl ester unit and vinyl alcohol unit. It is a percentage (mol%) of the amount (mol) of each unit with respect to (mol). However, the content of units other than ethylene units, vinyl ester units and vinyl alcohol units is extremely small as compared with these units. Therefore, the determined ethylene unit content (Et Cont.), Terminal carboxylic acid unit content (α) and terminal lactone ring unit content (β) are all units with respect to the total amount (mol) of all structural units. It is substantially equal to the percentage (mol%) of the quantity (mol).

<Measurement of melt flow rate (MFR)>
The dried resin composition pellets obtained in each reference example and reference comparative example were filled in a cylinder of Melt Indexer L244 (manufactured by Takara Kogyo Co., Ltd.) having an inner diameter of 9.55 mm and a length of 162 mm, and melted at 210 ° C. The molten resin composition was evenly loaded using a plunger having a mass of 2,160 g and a diameter of 9.48 mm. The amount of resin composition (g / 10 minutes) extruded per unit time from an orifice having a diameter of 2.1 mm provided in the center of the cylinder was measured and used as MFR.

<Sodium ion content, phosphoric acid content and boric acid content>
0.5 g of the dry resin composition pellets obtained in each reference example and reference comparative example was placed in a pressure vessel made of Teflon (registered trademark), 5 mL of concentrated nitric acid was added thereto, and the mixture was decomposed at room temperature for 30 minutes. After 30 minutes, the lid was closed, and the mixture was decomposed by heating at 150 ° C. for 10 minutes and then at 180 ° C. for 5 minutes using a wet decomposition apparatus (“MWS-2” manufactured by Actac Co., Ltd.), and then cooled to room temperature. This treatment liquid was transferred to a 50 mL volumetric flask (manufactured by TPX®) and prepared with pure water. For this solution, the contained metal was analyzed with an ICP emission spectroscopic analyzer ("OPTIMA4300DV" manufactured by PerkinElmer Co., Ltd.), and the content of sodium ion (sodium element) and phosphoric acid was contained as boric acid as a phosphoric acid root equivalent value. The amount was calculated as a boron element conversion value. For quantification, calibration curves prepared using commercially available standard solutions were used.

<Acetic acid content>
20 g of the dry resin composition pellets obtained in each Reference Example and Reference Comparative Example were put into 100 ml of ion-exchanged water, and heat-extracted at 95 ° C. for 6 hours. Using phenolphthalein as an indicator, the extract was neutralized and titrated with 1/50 standard NaOH to quantify the acetic acid content.

<Sorbic acid content>
The dried resin composition pellets obtained in each reference example and reference comparative example are frozen and pulverized, and then coarse particles are removed by a sieve (JIS standard Z8801-1 to 3) having a nominal size of 0.150 mm (100 mesh). 22 g of the pulverized product was filled in a Soxhlet extractor and extracted with 100 mL of chloroform for 16 hours. The amount of sorbic acid in the obtained chloroform extract was quantitatively analyzed by high performance liquid chromatography to quantify the content of sorbic acid in the resin composition. For quantification, a calibration curve prepared using a sorbic acid standard was used.

<Cinnamon acid content>
The dried resin composition pellets obtained in each reference example and reference comparative example are frozen and pulverized, and then coarse particles are removed by a sieve (JIS standard Z8801-1 to 3) having a nominal size of 0.150 mm (100 mesh). 22 g of the pulverized product was filled in a Soxhlet extractor and extracted with 100 mL of acetone for 16 hours. The amount of cinnamon acid in the obtained acetone extract was quantitatively analyzed by high performance liquid chromatography to quantify the content of cinnamon acid in the resin composition. For quantification, a calibration curve prepared using a cinnamic acid standard was used.

<Aluminum ion content>
15 g of the dry resin composition pellets obtained in each reference example and reference comparative example were weighed in a platinum crucible, and dry decomposition was carried out using nitric acid and sulfuric acid. 2 mL of hydrochloric acid was added to the incinerated sample, the volume was set in a 50 mL volumetric polytetrafluoroethylene (PTFE) measuring flask, and the sample solution was prepared by filtering with a PTFE filter having a pore size of 0.45 μm. Using the solution, the aluminum ion content in the resin composition was measured by high frequency plasma emission spectrometry (ICP emission spectrophotometer "IRIS AP" manufactured by Jarrel Ash).

<Synthesis Example 1> Synthesis of EVOH-A Vinyl acetate (hereinafter, may be referred to as VAc) is placed in a 200 L pressurized reaction vessel provided with a jacket, a stirrer, a nitrogen inlet, an ethylene inlet and an initiator addition port. 75.0 kg and 7.2 kg of methanol (hereinafter, may be referred to as MeOH) were charged, and nitrogen bubbling was performed for 30 minutes to replace the inside of the reaction vessel with nitrogen. Next, after adjusting the temperature in the reaction vessel to 65 ° C., ethylene was introduced so that the reaction vessel pressure (ethylene pressure) was 4.13 MPa, and 9.4 g of 2,2'-azobis (2) as an initiator was introduced. , 4-Dimethylvaleronitrile) (“V-65” manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was added to initiate polymerization. During the polymerization, the ethylene pressure was maintained at 4.13 MPa and the polymerization temperature was maintained at 65 ° C. After 4 hours, the mixture is cooled when the conversion rate of VAc (polymerization rate based on VAc) reaches 49.7%, and 0.2 g of copper acetate dissolved in 20 kg of methanol is put into a container for polymerization. It stopped. After opening the reaction vessel and deethyleneing, nitrogen gas was bubbled to completely deethylene. The polymerization solution was then removed from the container and diluted with 20 L of MeOH. This liquid is fed from the top of the column-shaped container, MeOH vapor is fed from the bottom of the column, and the unreacted monomer remaining in the polymerization solution is removed together with the MeOH vapor to remove an ethylene-vinyl acetate copolymer (hereinafter referred to as hereafter). A MeOH solution of (sometimes referred to as EVAc) was obtained.
Next, 150 kg of a 20 mass% MeOH solution of EVAc was charged into a 300 L reaction vessel equipped with a jacket, a stirrer, a nitrogen inlet, a reflux condenser and a solution addition port. The temperature was raised to 60 ° C. while blowing nitrogen gas into this solution, and a MeOH solution having a sodium hydroxide concentration of 2 was added at a rate of 450 mL / min for 2 hours. After the addition of the sodium hydroxide MeOH solution is completed, the temperature inside the system is kept at 60 ° C., and the saponification reaction is carried out by stirring for 2 hours while flowing out the MeOH and methyl acetate produced by the saponification reaction to the outside of the reaction vessel. I made it progress. Then, 8.7 kg of acetic acid was added to stop the saponification reaction.
Then, while heating and stirring at 80 ° C., 120 L of ion-exchanged water was added to allow MeOH to flow out of the reaction vessel to precipitate EVOH. EVOH precipitated by decantation was collected and crushed with a crusher. The obtained EVOH powder was put into a 1 g / L acetic acid aqueous solution (bath ratio 20: ratio of 20 L of aqueous solution to 1 kg of powder) and washed by stirring for 2 hours. This was deflated, further added to a 1 g / L acetic acid aqueous solution (bath ratio 20), and stirred and washed for 2 hours. The deflated product was put into ion-exchanged water (bath ratio 20), stirred and washed for 2 hours, and the operation of deflating the liquid was repeated 3 times for purification. The electrical conductivity of the cleaning liquid was 3 μS / cm (measured with “CM-30ET” of Toa Denpa Kogyo Co., Ltd.). Next, the crude EVOH was obtained by stirring and immersing it in 250 L of an aqueous solution containing 0.5 g / L of acetic acid and 0.1 g / L of sodium acetate for 4 hours, then removing the liquid, and drying this at 60 ° C. for 16 hours. 16.1 kg was obtained. The above operation was repeated to obtain 15.9 kg of a crude product of EVOH, whereby a total of 32.0 kg of a crude product of EVOH (EVOH-A) was obtained.

<Preparation of resin composition>
[Reference Examples 1 to 6 and Reference Comparative Examples 1 to 3]
In a 60 L stirring tank equipped with a jacket, a stirrer and a reflux condenser, 2 kg of a crude dried product of EVOH (EVOH-A) obtained in Synthesis Example 1, 0.8 kg of water and 2.2 kg of MeOH were charged, and the mixture was charged at 60 ° C. for 5 hours. It was stirred and completely dissolved. Aluminum acetate was added to the obtained solution, and the mixture was further stirred for 1 hour to completely dissolve the aluminum acetate to obtain a resin composition solution. In Reference Comparative Example 3, a resin composition solution was obtained without adding aluminum acetate. This solution is extruded into a mixed solution of water / MeOH = 90/10 cooled to -5 ° C through a gold plate having a diameter of 4 mm to precipitate in the form of strands, and the strands are cut into pellets with a strand cutter to obtain EVOH. Moisture-containing pellets were obtained. The water content of the obtained EVOH water-containing pellets was measured with a halogen moisture meter "HR73" manufactured by METTLER CORPORATION and found to be 52% by mass. The obtained water-containing pellets of EVOH were put into a 1 g / L acetic acid aqueous solution (bath ratio 20) and washed with stirring for 2 hours. This was deflated, further added to a 1 g / L acetic acid aqueous solution (bath ratio 20), and stirred and washed for 2 hours. After the liquid was removed, the acetic acid aqueous solution was updated and the same operation was performed. After washing with an aqueous acetic acid solution, the liquid was drained, put into ion-exchanged water (bath ratio 20), stirred and washed for 2 hours, and the operation of draining was repeated 3 times, and the electrical conductivity of the washing liquid was 3 μS /. Purification was carried out to cm (measured with "CM-30ET" of Toa Denpa Kogyo Co., Ltd.) to obtain a water-containing pellet of EVOH from which the catalyst residue during the saponification reaction was removed.
The hydrous pellet is put into an aqueous solution (bath ratio 20) having a sodium acetate concentration of 0.510 g / L, an acetic acid concentration of 0.8 g / L, and a phosphoric acid concentration of 0.04 g / L, and is periodically stirred for 4 hours. It was soaked and chemically treated. The pellets are deflated and dried at 80 ° C. for 3 hours and 105 ° C. for 16 hours under a nitrogen stream having an oxygen concentration of 1% by volume or less to obtain EVOH-A, acetic acid, sodium ion (sodium salt), phosphoric acid and the like. A columnar dry resin composition pellet having an average diameter of 2.8 mm and an average length of 3.2 mm containing aluminum ions (aluminum salt) was obtained. The aluminum ion content in each reference example and reference comparative example was adjusted so as to be as shown in Table 3 by adjusting the addition amount of aluminum acetate. The ethylene content of EVOH-A, the degree of saponification, the terminal lactone ring unit content, the terminal carboxylic acid unit content, the total content of the terminal carboxylic acid unit and the terminal lactone ring unit, in the obtained dry resin composition pellets, The lactone ring unit ratio, MFR, and boric acid content were quantified using the above quantification method using a dry resin composition pellet having an aluminum ion content of 0.3 ppm as a sample (hereinafter, the same applies). Table 2 shows the ethylene content, saponification degree, terminal lactone ring unit content, terminal carboxylic acid unit content, total content of terminal carboxylic acid units and terminal lactone ring unit, lactone ring unit ratio, MFR and boric acid content. Shown in. In each of the dried resin composition pellets, the sodium ion content was 90 to 110 ppm, the phosphoric acid content was 35 to 45 ppm in terms of phosphoric acid root, and the acetic acid content was 190 to 210 ppm. Further, FIG. 1 shows a ¹ H-NMR spectrum of EVOH-A measured under the conditions of the solvent DMSO-d ₆ and the measurement temperature of 25 ° C. FIG. 2 shows a ¹ H-NMR spectrum of EVOH-A measured under the conditions of the solvent DMSO-d ₆ and the measurement temperature of 80 ° C. FIG. 3 shows a ¹ H-NMR spectrum of EVOH-A measured under the conditions of solvent D ₂ O + MeOD and measurement temperature: 80 ° C.

<Synthesis Examples 2 to 11>
The amount of raw material added for the polymerization of EVOH, the polymerization conditions, the amount charged in the saponification treatment, and the addition rate of the specified sodium hydroxide MeOH solution were as shown in Table 1, and the synthesis was performed only once. In the same manner as in Example 1, 10.1 to 11.5 kg of a crude dried product of each EVOH (EVOH-B to EVOH-K) was obtained.

<Preparation of resin composition>
[Reference Examples 7 to 27, 34 and Reference Comparative Examples 4 to 23]
Reference examples except that the crude dried products of each EVOH (EVOH-B to EVOH-K) obtained in the above synthesis examples 2 to 11 were used and the components contained in the aqueous solution in the chemical treatment were as shown in Table 1. Each dry resin composition pellet was obtained in the same manner as in 1. Further, similarly to Reference Example 1 and the like, the aluminum ion content was adjusted as shown in Tables 3 to 12 and 14 by adjusting the addition amount of aluminum acetate. Various measurements were also quantified using the above quantification method in the same manner as in Reference Example 1. Table 2 shows the ethylene content, saponification degree, terminal lactone ring unit content, terminal carboxylic acid unit content, total content of terminal carboxylic acid units and terminal lactone ring unit, lactone ring unit ratio, MFR and boric acid content. Shown in. The sodium ion content of each of the dried resin composition pellets was 90 to 110 ppm, the phosphoric acid content was 35 to 45 ppm in terms of phosphoric acid root, and the acetic acid content was 190 to 210 ppm.

<Preparation of resin composition>
[Reference Examples 28 to 33 and Reference Comparative Example 24]
2 kg of a crude dried product of EVOH (EVOH-A) obtained in Synthesis Example 1, 0.8 kg of water and 2.2 kg of MeOH were charged and stirred at 60 ° C. for 5 hours to completely dissolve them. Aluminum acetate, sorbic acid or cinnamic acid was added to the obtained solution, and the mixture was further stirred for 1 hour to completely dissolve the aluminum acetate and sorbic acid or cinnamic acid to obtain a resin composition solution. In Reference Comparative Example 24, aluminum acetate was not added and only sorbic acid was added to obtain a resin composition solution. The subsequent treatment was the same as in Reference Example 1 to obtain pellets of each dry resin composition. By adjusting the addition amount of aluminum acetate for aluminum ions and adjusting the addition amount of sorbic acid or cinnamic acid, dry resin composition pellets are obtained as shown in Table 13. rice field. Various measurements were also quantified using the above quantification method in the same manner as in the reference example. The sodium ion content of each of the dried resin composition pellets was 90 to 110 ppm, the phosphoric acid content was 35 to 45 ppm in terms of phosphoric acid root, and the acetic acid content was 190 to 210 ppm.

In Tables 3 to 14 and the like, the total content (mol%) of the terminal carboxylic acid units and the lactone ring unit with respect to the total amount of ethylene unit, vinyl alcohol unit and vinyl acetate unit in EVOH is converted into 1 g of EVOH. The total content (μmol / g) of the terminal carboxylic acid units and the terminal lactone ring unit per unit is also shown. In addition, the aluminum ion content (ppm) in the resin composition and the converted aluminum ion content (μmol / g) per 1 g of EVOH are also shown. Further, the ratio ((i + ii) / b) of the total content (i + ii: μmol / g) of the terminal carboxylic acid unit and the terminal lactone ring unit per 1 g of EVOH and the content of aluminum ions (b: μmol / g) per 1 g of EVOH. ) Is also shown.

<Preparation of Antioxidant (G) Blend Resin Composition>
[Examples 1 and 2 and Comparative Examples 1 and 2]
N, N'-(hexane-1,6--), which are antioxidants, are applied to the resin compositions containing EVOH-A and EVOH-D obtained in Reference Examples 2 and 14 and Reference Comparative Examples 1 and 2, respectively. Diyl) bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionamide] (BASF Japan, Inc. "Irganox1098", molecular weight: 637) was dry-blended at the blending amounts shown in Table 15. , A resin composition pellet was obtained by extruding in a nitrogen atmosphere at an extrusion temperature of 220 ° C. using a 30 mmφ isodirectional twin-screw extruder (“TEX-30N” manufactured by Japan Steel Works, Ltd.).

<Preparation of Blend Resin Composition of Antioxidant (G) and Thermoplastic Elastomer (F)>
The thermoplastic elastomer (F) used is as follows.
F-5: Toughmer (registered trademark) MH7020 (manufactured by Mitsui Chemicals, Inc., maleic anhydride-modified ethylene-butene copolymer)

[Example 3]
After dry-blending 90 parts by mass of the resin composition containing EVOH-D obtained in Reference Example 14, 10 parts by mass of the thermoplastic elastomer (F-5), and 0.5 parts by mass of the above-mentioned antioxidant (Irganox1098). Resin composition pellets were obtained by extruding under the following conditions.
Extrusion condition device: 30 mmφ twin-screw extruder L / D: 45.5
Screw: Same-direction perfect mesh extrusion temperature (° C): 220 ° C
Rotation speed: 200 rpm
Discharge rate: 20 kg / hr

<Evaluation>
<Conditions for producing a single-layer film>
The resin composition pellets obtained in Reference Examples 1 to 34, Reference Comparative Examples 1 to 24, Examples 1 to 3 and Comparative Examples 1 and 2 were formed under the following conditions to obtain a single-layer film having a thickness of 20 μm. rice field.
・ Equipment: 20 mmφ single-screw extruder (D2020, manufactured by Toyo Seiki Seisakusho Co., Ltd.)
・ L / D: 20
・ Screw: Full flight ・ Dice width: 30 cm
-Take-up roll temperature: 80 ° C
・ Screw rotation speed: 40 rpm
・ Take-up roll speed: 3.0 to 3.5 m / min ・ Set temperature: C1 / C2 / C3 / D = 180 ° C / 210 ° C / 210 ° C / 210 ° C

<Suppression of the occurrence of stuff (things)>
The number of gel-like lumps (150 μm or more that can be visually confirmed) of the single-layer film produced 50 hours after the start of operation was counted and converted to about 1.0 m ² . Judgment was made as follows based on the number of lumps per 1.0 m ² . The evaluation results are shown in Tables 3-14 and 16.
A: Less than 20 B: 20 or more and less than 40 C: 40 or more and less than 100 D: 100 or more When the evaluation results are A to B, the occurrence of lumps is sufficiently suppressed and no problem occurs. It is a level. Even when the evaluation result is C, the occurrence of lumps is suppressed, and lumps may become a problem depending on the application, but it is a usable level. When the evaluation result is D, it is a level that cannot be used due to a large amount of lumps.

<Heat and light resistance test>
The obtained single-layer film is cut into a size of 150 mm in the TD direction and 70 mm in the MD direction, attached to a PTFE sheet of the same size and a thickness of 0.3 mm, and set in a sample holder having an opening of 135 mm in width and 55 mm in height. did. Using the Super Xenon Weather Meter SX75 manufactured by Suga Test Instruments Co., Ltd., ultraviolet rays were continuously irradiated for 48 hours under the conditions of irradiance of 150 W / m ² , black panel temperature of 83 ° C., and humidity in the tank of 50% RH. After irradiation, the unirradiated portion around the film was cut off to obtain a film sample of a heat resistance and light resistance test having a width of 135 mm and a height of 55 mm.

<Elongation at break>
The obtained single-layer film was cut into a film sample having a size of 150 mm in the TD direction and 70 mm in the MD direction, and cuts at intervals of 15 mm were made in advance with a razor blade, and the film sample was irradiated with ultraviolet rays in the same manner as in the above heat resistance and light resistance test. The sample after irradiation with ultraviolet rays was cut into a width of 15 mm and a length of 50 mm to prepare a sample for a tensile test, and the sample was conditioned for 5 days at a temperature of 23 ° C. and a humidity of 50% RH. The sample after humidity control is subjected to a tensile test in the MD direction at a tensile tester (“AUTOGRAPH AGS-H” manufactured by Shimadzu Corporation) with a chuck distance of 30 mm and a tensile speed of 500 mm / min at N = 5, and the elongation at break is determined. Measured (evaluation after heat resistance and light resistance test). In addition, the elongation at break was measured in the same manner for the film sample that was not irradiated with ultraviolet rays (evaluation before the heat resistance and light resistance test). The reduction rate (%) of the elongation at break after the heat resistance test was calculated with respect to the elongation at break before the heat resistance test. The evaluation results are shown in Tables 3-14 and 16. It was judged that the lower the rate of decrease in elongation at break, the better the heat resistance and light resistance.

<Mass loss: Accelerated microplasticization test>
Four film samples after the heat resistance and light resistance test treatment were prepared, vacuum dried at 60 ° C. for 24 hours, and then the total dry mass (W1) of the four film samples before the pulverization treatment described later was measured. Four film samples after the heat resistance and light resistance test, 500 g of zirconia balls having a diameter of 3 mm, and 100 mL of deionized water were put into a ceramic pot mill made of alumina having a capacity of 300 mL. A closed pot mill was installed on a tabletop pot mill stand "PM-001" manufactured by AS ONE Corporation, operated at a rotation speed of 200 rpm, and crushed at room temperature for 4 hours. The contents of the crushed pot mill were taken out together with water, and the work of adding deionized water, stirring and decanting was repeated to separate the zirconia balls from the crushed material and water. The contents from which the zirconia balls had been removed were filtered under reduced pressure with a nylon mesh having an opening of 46 μm, and the filtrate was vacuum dried at 60 ° C. The mass (W2) of the crushed material of 46 μm or more remaining after being filtered with a nylon mesh was measured, and the mass loss (M) was calculated according to the following formula (i) (evaluation after the heat resistance and light resistance test).
M (%) = (W1-W2) / W1 × 100 ... (i)
In addition, the mass loss of the film sample that was not subjected to the ultraviolet irradiation test was measured in the same manner (evaluation before the heat resistance and light resistance test). The evaluation results are shown in Tables 3-14 and 16.
The value of mass loss in the evaluation after the heat resistance and light resistance test is used as an index for microplasticization, and the smaller the value, the more the microplasticization can be suppressed.

<Pipe evaluation test>
[Manufacturing of multi-layer pipe]
100 parts by mass of high-density polyethylene ("Yukaron Hard BX-50" manufactured by Mitsubishi Yuka Co., Ltd., density 0.952 g / cc, MFR 0.5 g / 10 minutes), 2 parts by mass of vinyltrimethoxysilane dissolved in acetone, and dicumyl. 0.2 parts by mass of the peroxide was mixed. The mixture was extruded into a strand at 230 ° C. using a uniaxial screw to obtain pellets of modified polyethylene to which 1.5% by mass of vinylsilane was added. Next, Examples 1 to 3 and a mixture of 100 parts by mass of the pellets and 5 parts by mass of the above-mentioned high-density polyethylene in which dibutyltin laurate was mixed in a ratio of 2% by mass were used in the first extruder. Each resin composition pellet obtained in Comparative Examples 1 and 2 was put into a second extruder, and "Admer NF408E" manufactured by Mitsui Chemicals Co., Ltd. was put into a third extruder as an adhesive resin. A multi-layer pipe having an outer diameter of 20 mm was extruded using a circular die of the layer, and immediately after that, it was cooled and solidified through a cooling water tank adjusted to 40 ° C. The layer structure of the multilayer pipe was such that the resin composition layer was the outermost layer, and the resin composition layer / adhesive resin layer / high-density polyethylene layer = 100 μm / 100 μm / 2000 μm. The obtained multi-layer pipe is cut to 1 m, placed in a hot air dryer at 140 ° C for 10 minutes, heated, and then bent 90 ° along a stainless steel pipe with an outer diameter of 150 mm near the center and fixed for 5 minutes for bending. Was done.

<OTR (oxygen permeability)>
By sealing one end of the manufactured multi-layer pipe with a silicon rubber stopper and an adhesive, and connecting the other end to an oxygen permeation measuring device (OX-TRAN-10 / 50A manufactured by Modern Control Co., Ltd.), the temperature is 20 ° C./65. Oxygen permeability before heat treatment was measured under the condition of% RH. The results obtained are shown in Table 16.

Next, the multilayer pipe was placed in a hot air dryer at 100 ° C. and heat-treated for 216 hours. The oxygen permeability after the heat treatment was measured by the above method using the multi-layer pipe after the heat treatment. The results obtained are shown in Table 16.

[Evaluation of oxidative deterioration resistance]
For each of the single-layer films of Examples 1 to 3 and Comparative Examples 1 and 2 obtained above, by measuring a plurality of samples having different heat treatment times under the following evaluation conditions, the tensile strength and elongation with time. The change was evaluated. The time required for the elongation at break to become 1/4 of that of the sample not subjected to heat treatment was determined and used as an index of oxidation deterioration resistance. The evaluation results are shown in Table 16.
Evaluation conditions:
After processing in a hot air dryer set at 140 ° C. for a predetermined time, it was taken out. Then, it was immersed in water at 20 ° C. for 5 days, the surface water was wiped off, and the mixture was allowed to stand in a room at 20 ° C.-65% RH for 2 weeks, and then the tensile strength and elongation were measured under the following conditions.
Measurement conditions Sample width 15 mm
Chuck spacing 30 mm
Tensile speed 50 mm / min Measurement atmosphere 20 ° C-65% RH

In the above evaluation, when the elongation at break becomes 1/4 or less, the deterioration of the gas barrier property of the EVOH layer due to the generation of cracks due to oxidative deterioration becomes remarkable. Therefore, the time during which the elongation at break becomes 1/4 is set as EVOH. It can be considered as one of the indexes of life due to oxidative deterioration at high temperature. The time when the elongation at break becomes 1/4 shows the temperature dependence of the Arrhenius type, and when the time (life) at which the elongation at break becomes 1/4 at 80 ° C is to be 100 years or more, the elongation at break at 140 ° C. It is necessary to set the time for the degree to be 1/4 to 210 hours or more.

<Discussion>
As shown in Table 3, the resin composition of Reference Comparative Example 3 which does not contain aluminum ions has an insufficient effect of suppressing the generation of lumps, and has heat resistance and light resistance (rate of decrease in elongation at break) and microplastic. Chemical resistance (mass loss in evaluation after heat resistance and light resistance test) was also relatively large. On the other hand, the resin composition of Reference Comparative Example 1 containing a small amount of aluminum ions tended to be improved as compared with the resin composition of Reference Comparative Example 3, but the improvement effect was low. .. In addition, the resin composition of Reference Comparative Example 2 containing a large amount of aluminum ions did not improve the effect of suppressing the generation of lumps. On the other hand, the resin compositions of Reference Examples 1 to 6 in which the content (b) of aluminum ion (B) per 1 g of EVOH (A) is in the range of 0.002 μmol / g or more and 0.17 μmol / g or less. It can be seen that, as compared with the resin composition of Reference Comparative Example 1 containing a small amount of aluminum ions, the effect of suppressing lumps, heat resistance and light resistance, and resistance to microplasticization were further improved.

Tables 4 to 10 show the results using other EVOH. From these as well, similar to the results in Table 3, when the content (b) of aluminum ion (B) per 1 g of EVOH (A) is within the range of 0.002 μmol / g or more and 0.17 μmol / g or less. It can be seen that the effect of suppressing lumps, heat resistance and light resistance, and resistance to microplasticization are improved.

As shown in Table 3, when the content of aluminum ions was low (0.02 ppm, 0.001 μmol / g), the improvement effect was insufficient, so aluminum was also used in Tables 4 to 10. Based on the reference comparative example with an ion content of 0.02 ppm (0.001 μmol / g), those improved from this are evaluated as “+” and those not improved are evaluated as “-”, and these are evaluated as “-”. Shown in the table.

On the other hand, as shown in Table 11, when the total content (i + ii) of the terminal carboxylic acid unit and the terminal lactone ring unit is too small, even if the aluminum ion content is adjusted, in the evaluation after the heat resistance test. The mass loss was 14.0% by mass or more, and it did not have sufficient resistance to microplasticization. Further, as shown in Table 12, when the total content (i + ii) of the terminal carboxylic acid unit and the terminal lactone ring unit is too large, even if the content of the aluminum ion is adjusted, the evaluation of the lump is D. , The occurrence of lumps could not be sufficiently suppressed.

From the above results, when the total content (i + ii) of the terminal carboxylic acid unit and the terminal lactone ring unit per 1 g of EVOH (A) is within the range of 14 μmol / g or more and 78 μmol / g or less, per 1 g of EVOH (A). By setting the content (b) of the aluminum ion (B) in the range of 0.002 μmol / g or more and 0.17 μmol / g or less, the generation of lumps during melt molding is suppressed and sufficient heat resistance and light resistance are obtained. It can be seen that it is a resin composition that can be obtained as a molded product that has and is difficult to be microplasticized after disposal, and that a resin composition in which each of the above characteristics is sufficiently improved as compared with the one using the same EVOH can be obtained. ..

Further, as shown in Table 13, in addition to aluminum ions, at least one compound selected from the group consisting of cinnamon acids and conjugated polyene compounds having a molecular weight of 1,000 or less is further contained to achieve heat resistance and light resistance and microplastics. It can be seen that the resistance to cinnamon is further improved.

As shown in Table 14, when comparing Reference Example 8 in which EVOH using almost the same EVOH except for the lactone ring unit ratio is used with Reference Example 34, Reference Example 8 in which EVOH-B having a high lactone ring unit ratio is used is It can be seen that the heat resistance and light resistance and the resistance to microplasticization are high.

Further, as shown in Tables 15 and 16, the total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) per 1 g of EVOH (A) is 14 μmol / g or more and 78 μmol / g or less. , The content (b) of aluminum ion (B) per 1 g of EVOH (A) is within the range of 0.002 μmol / g or more and 0.17 μmol / g or less, and the antioxidant (G) is contained in a predetermined amount. When contained in an amount, in addition to the effect of suppressing lumps, heat resistance and light resistance, and resistance to microplasticization, gas barrier properties (OTR), especially gas barrier properties after heat treatment, and oxidation deterioration resistance are also improved. Good results.

In Table 16, the effect of suppressing lumps, heat resistance and light resistance, and resistance to microplasticization are based on Comparative Example 1 in Table 16, and those improved from this are indicated by "+", and those not improved are indicated by "+". It was evaluated as "-" and these are shown in Table 16. However, by adjusting the content (b) of the aluminum ion (B) from the comparison between Comparative Examples 1 and 2 in Table 16 and Example 1, the content (b) of the aluminum ion (B) is adjusted to compare with the one using the same type of EVOH. It can also be confirmed that the resin composition of each example has an improved effect of suppressing lumps, heat resistance and light resistance, and resistance to microplasticization.

Further, from the comparison between Reference Example 2 and Example 1, it can be seen that the heat resistance and light resistance and the resistance to microplasticization are further enhanced by containing a predetermined amount of the antioxidant (G).

Further, in addition to the resin compositions of Examples 1 to 3, the resin composition of the present invention can be prepared, for example, by mixing a predetermined amount of the antioxidant (G) with the resin compositions of Reference Examples 1 to 34. From the results of Reference Examples 1 to 34, such a resin composition also suppresses the generation of lumps during melt molding, has sufficient heat and light resistance, and is difficult to be microplasticized after disposal. It is clear that the resin composition obtained by the body is sufficiently improved in each of the above-mentioned properties as compared with the one using the same EVOH. Therefore, even in the case of a resin composition having a composition containing EVOH (A), aluminum ion (B) and an antioxidant (G) other than the resin compositions of Examples 1 to 3, the carboxylic acid units per gram (I). ) And EVOH (A) having a total content (i + ii) of 14 μmol / g or more and 78 μmol / g or less of the lactone ring unit (II), and the content of aluminum ion (B) per 1 g of EVOH (A) (b). ) Is adjusted within the range of 0.002 μmol / g or more and 0.17 μmol / g or less, and the content of the antioxidant (G) is also within the predetermined range. It is considered that it is sufficiently shown from the results of Reference Examples 1 to 34 that the chemical resistance is improved and the oxidation deterioration resistance is also improved.

The resin composition of the present invention is useful as a molding material for various molded bodies, laminates, pipes and the like.

Claims (13)

A resin composition containing an ethylene-vinyl alcohol copolymer (A), aluminum ions (B) and an antioxidant (G).
At least a part of the ethylene-vinyl alcohol copolymer (A) has at least one of a carboxylic acid unit (I) and a lactone ring unit (II) located at the terminal of the polymer.
The total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) per 1 g of the ethylene-vinyl alcohol copolymer (A) is 14 μmol / g or more and 78 μmol / g or less.
The content (b) of aluminum ions (B) per 1 g of the ethylene-vinyl alcohol copolymer (A) is 0.002 μmol / g or more and 0.17 μmol / g or less.
A resin composition in which the content (g) of the antioxidant (G) with respect to the ethylene-vinyl alcohol copolymer (A) is 0.01% by mass or more and 5% by mass or less. The ratio ((i + ii) / b) of the total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) to the content (b) of the aluminum ion (B) is 180 or more and 20,000 or less. The resin composition according to claim 1. The resin composition according to claim 1 or 2, wherein the aluminum ion (B) is derived from a fatty acid aluminum salt having 5 or less carbon atoms. Further containing at least one compound (C) selected from the group consisting of cinnamon acids and conjugated polyene compounds having a molecular weight of 1,000 or less.
The resin composition according to any one of claims 1 to 3, wherein the content (c) of the compound (C) with respect to the ethylene-vinyl alcohol copolymer (A) is 1 ppm or more and 1,000 ppm or less. Claimed that the ratio (ii / (i + ii)) of the content (ii) of the lactone ring unit (II) to the total content (i + ii) of the carboxylic acid unit (I) and the lactone ring unit (II) is 40 mol% or more. Item 2. The resin composition according to any one of Items 1 to 4. Further containing the thermoplastic elastomer (F),
The one according to any one of claims 1 to 5, wherein the mass ratio (F / A) of the thermoplastic elastomer (F) to the ethylene-vinyl alcohol copolymer (A) is 5/95 or more and 35/65 or less. Resin composition. The resin composition according to claim 6, wherein the thermoplastic elastomer (F) is at least one selected from the group consisting of a polyester-based thermoplastic elastomer, a polystyrene-based thermoplastic elastomer, and a polyolefin-based thermoplastic elastomer. A molded product molded from the resin composition according to any one of claims 1 to 7. A laminate having a layer made of the resin composition according to any one of claims 1 to 7 and at least one other layer. A pipe having a layer made of the resin composition according to any one of claims 1 to 7. A hot water circulation pipe comprising the pipe according to claim 10. The heat insulating multi-layer pipe comprising the pipe according to claim 10, further comprising a heat insulating foam layer. A fuel pipe comprising the pipe according to claim 10.

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