JP7149842B2 - Resin composition, molding, multi-layer structure, agricultural film and geomembrane - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition, a molded article and a multilayer structure.

In general, ethylene-vinyl alcohol copolymers are excellent in transparency, gas barrier properties, aroma retention properties, solvent resistance, oil resistance, etc., and are used in various applications such as foods, pharmaceuticals, industrial chemicals, and agricultural chemicals. It is used for films and sheets such as packaging materials, and containers such as bottles. Ethylene-vinyl alcohol copolymers are also used for applications such as agricultural films and geomembranes, taking advantage of their barrier properties, heat retention, and stain resistance.

Ethylene-vinyl alcohol copolymers have lower thermal stability than other resins, and may be colored depending on the production conditions. In addition, when exposed to light, heat, etc. due to outdoor use, coloring may occur and mechanical strength may decrease. Regarding a resin composition containing an ethylene-vinyl alcohol copolymer, Patent Document 1 discloses an ethylene-vinyl ester copolymer saponified product (A) and a cinnamic acid ester (B), and a cinnamic acid ester (B ) is 0.01 to 10 ppm relative to the saponified ethylene-vinyl ester copolymer (A). This resin composition absorbs wavelengths in a specific ultraviolet region (for example, UV-B and UV-C with a wavelength of less than 320 nm) while maintaining excellent transparency, and can form a film that does not cause odor problems. It is said that Further, Patent Document 2 discloses an ethylene-vinyl ester copolymer saponified product (A), cinnamic acids (B), and at least one (C) of an alkali metal salt (C1) and an alkaline earth metal salt (C2). (wherein component (C) excludes cinnamate). It is said that this resin composition absorbs wavelengths in a specific ultraviolet region and can form a molded article that suppresses deterioration of the ultraviolet absorption effect and generation of odor due to contents containing an alcohol component.

WO2016/199827 WO2017/104673

It has been found that even with the resin composition containing the above-mentioned ethylene-vinyl alcohol copolymer, there is still room for improvement in terms of problems such as occurrence of coloring and reduction in mechanical strength associated with outdoor use. On the other hand, during the melt molding of the ethylene-vinyl alcohol copolymer, it is desirable that no odor or gel-like lumps are generated. Note that gel-like lumps not only impair the appearance of the molded product but also cause performance deterioration, so it is necessary to suppress the occurrence of these.

The present invention has been made based on the above circumstances, and its purpose is to suppress the occurrence of odor and lumps during melt molding, etc., and to improve the coloration and mechanical strength associated with outdoor use. It is an object of the present invention to provide a resin composition capable of obtaining a molded article with little decrease in , and a molded article, a multilayer structure, etc. using the resin composition.

According to the present invention the above objects are:
[1] Ethylene-vinyl alcohol copolymer (A), cinnamic acids (B), and aluminum salt (C) of fatty acid having 5 or less carbon atoms (hereinafter sometimes simply referred to as "aluminum salt (C)") , the content of cinnamic acids (B) with respect to the ethylene-vinyl alcohol copolymer (A) is 1 to 100 ppm, and the content of the aluminum salt (C) with respect to the ethylene-vinyl alcohol copolymer (A) is aluminum A resin composition that is 0.08 to 6 ppm in terms of conversion;
[2] The resin composition of [1], wherein the aluminum salt (C) is aluminum acetate and/or aluminum propionate;
[3] The resin composition of [1] or [2], wherein the molar ratio of cinnamic acids (B) to aluminum in the aluminum salt (C) (cinnamic acids (B)/aluminum) is 0.7 to 60;
[4] Molded article molded from the resin composition of any one of [1] to [3];
[5] A multilayer structure having a layer made of the resin composition of any one of [1] to [3];
[6] Agricultural film having a layer made of the resin composition of any one of [1] to [3];
[7] The multilayer structure of [5] used in large silo films, soil fumigation films, grain storage bags or silage films;
[8] A geomembrane having a layer made of the resin composition of any one of [1] to [3];
This is achieved by providing

INDUSTRIAL APPLICABILITY According to the present invention, a resin composition that suppresses the generation of odors and lumps during melt molding and the like, and can obtain a molded article that is less likely to be colored or reduced in mechanical strength due to outdoor use, and Molded articles and multi-layer structures using the resin composition, particularly agricultural films, large silo films, soil fumigation films, grain storage bags, silage films and geomembrane can be provided.

<Resin composition>
The resin composition of the present invention contains an ethylene-vinyl alcohol copolymer (A) (hereinafter sometimes referred to as "EVOH (A)"), cinnamic acids (B), and an aluminum salt (C), and EVOH The content of cinnamic acids (B) relative to (A) is 1 to 100 ppm, and the content of aluminum salt (C) is 0.08 to 6 ppm in terms of aluminum. In addition, in this specification, "ppm" is a content rate based on mass.

(EVOH (A))
EVOH (A) is a copolymer having ethylene units and vinyl alcohol units. EVOH (A) is usually obtained by saponifying an ethylene-vinyl ester copolymer. Production and saponification of the ethylene-vinyl ester copolymer can be carried out by known methods. Vinyl esters are typically vinyl acetate, but other vinyl fatty acids such as vinyl formate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl pivalate and vinyl versatate. It may be an ester.

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 50 mol%, and even more preferably 45 mol%. When the ethylene unit content is 10 mol % or more, the thermal stability tends to be further improved. Moreover, when the ethylene unit content is 60 mol % or less, the oxygen barrier property and the melt tension tend to be improved.

The degree of saponification of EVOH (A) is preferably 90 mol% or more, more preferably 95 mol% or more, even more preferably 99 mol% or more. When the degree of saponification of EVOH (A) is 90 mol % or more, the gas barrier properties, thermal stability, and moisture resistance of the obtained molded article tend to be good. The degree of saponification may be 100 mol % or less, 99.97 mol % or less, or 99.94 mol % or less.

EVOH (A) may have units derived from monomers other than ethylene, vinyl esters and saponified products thereof as long as the effects of the present invention are not impaired. The content of units derived from other monomers (units other than ethylene units, vinyl ester units and vinyl alcohol units) relative to the total structural units of EVOH (A) is preferably 30 mol% or less, more preferably 20 mol% or less. , is more preferably 10 mol % or less, even more preferably 5 mol % or less, and particularly preferably 1 mol % or less. When EVOH (A) has units derived from the other monomers, 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 their anhydrides, salts, or mono- or dialkyl esters; nitriles such as acrylonitrile and methacrylonitrile; acrylamide and methacryl; Amides such as amides; Olefinsulfonic acids such as vinylsulfonic acid, allylsulfonic acid, methallylsulfonic acid and salts thereof; Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(β-methoxy-ethoxy)silane, γ-methacryloxy vinylsilane compounds such as propylmethoxysilane; alkyl vinyl ethers, vinyl ketones, N-vinylpyrrolidone, vinyl chloride, vinylidene chloride and the like.

In addition, units derived from other monomers are represented by structural unit (I) represented by formula (I) below, structural unit (II) represented by formula (II) below, and formula (III) below. may be at least one of the structural units (III).

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 each independently a hydrogen atom having 1 to 10 carbon atoms. 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. Pairs of R ¹ , R ² and R ³ , R ⁴ and R ⁵ , R ⁶ and R ⁷ may be linked. In addition, part 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 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 each independently represent a hydrogen atom, a formyl group or an alkanoyl group having 2 to 10 carbon atoms.

When EVOH (A) has the structural unit (I), (II) or (III), the flexibility and processability of the resin composition are improved, and the stretchability and thermoformability of the resulting molded article or multilayer structure are improved. etc. tend to be good.

In the structural unit (I), (II) or (III), examples of aliphatic hydrocarbon groups having 1 to 10 carbon atoms include alkyl groups and alkenyl groups. Examples of alicyclic hydrocarbon groups having 3 to 10 carbon atoms include cycloalkyl groups and cycloalkenyl groups. Examples of aromatic hydrocarbon groups having 6 to 10 carbon atoms include phenyl groups.

In structural unit (I), R ¹ , R ² and R ³ are each independently preferably a hydrogen atom, a methyl group, an ethyl group, a hydroxyl group, a hydroxymethyl group and a hydroxyethyl group. From the viewpoint of further improving the stretchability and thermoformability of the structure and the like, it is more preferable that they are each independently a hydrogen atom, a methyl group, a hydroxyl group and a hydroxymethyl group.

The method for incorporating the structural unit (I) into the EVOH (A) is not particularly limited. For example, in the polymerization of ethylene and vinyl ester, a method of copolymerizing a monomer derived from the structural unit (I) can be used. is mentioned. Examples of monomers derived from the structural unit (I) include alkenes such as propylene, butylene, pentene, and hexene; 3-hydroxy-1-propene, 3-acyloxy-1-propene, 3-acyloxy-1-butene; , 3-hydroxy-1-butene, 4-hydroxy-1-butene, 4-acyloxy-1-butene, 3,4-diacyloxy-1-butene, 3-acyloxy-4-hydroxy-1-butene, 4-acyloxy -3-hydroxy-1-butene, 3-acyloxy-4-methyl-1-butene, 4-acyloxy-2-methyl-1-butene, 4-acyloxy-3-methyl-1-butene, 3,4-diacyloxy -2-methyl-1-butene, 4-hydroxy-1-pentene, 5-hydroxy-1-pentene, 4,5-dihydroxy-1-pentene, 4-acyloxy-1-pentene, 5-acyloxy-1-pentene , 4,5-diacyloxy-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 -acyloxy-1-hexene, 5,6-diacyloxy-1-hexene and other alkenes having a hydroxyl group or an ester group. Among them, propylene, 3-acyloxy-1-propene, 3-acyloxy-1-butene and 4-acyloxy-1 -butene, 3,4-diacyloxy-1-butene are preferred. Incidentally, "acyloxy" is preferably acetoxy, specifically 3-acetoxy-1-propene, 3-acetoxy-1-butene, 4-acetoxy-1-butene and 3,4-diacetoxy-1-butene is preferred. In the case of alkenes having esters, they are derived into the structural unit (I) during the saponification reaction.

^In structural unit (II), both ^R4 and R5 are preferably hydrogen atoms. More preferably, both R ⁴ and R ⁵ are hydrogen atoms, one of R ⁶ and R ⁷ is a C 1-10 aliphatic hydrocarbon group, and the other is a hydrogen atom. Alkyl groups and alkenyl groups are preferred as aliphatic hydrocarbon groups. From the viewpoint of placing particular importance on the gas barrier properties of the resulting 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. 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. Incidentally, h is preferably an integer of 1 to 4, more preferably 1 or 2, and even more preferably 1.

The method of incorporating the structural unit (II) into EVOH (A) is not particularly limited, and a method of reacting EVOH (A) 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 are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms (alkyl group, alkenyl group, etc.), ~10 alicyclic hydrocarbon group (cycloalkyl group, cycloalkenyl group, etc.) or C6-10 aliphatic hydrocarbon group (phenyl group, etc.). i, j, k, p and q each independently represents an integer of 1 to 8; However, when R ¹⁷ is a hydrogen atom, R ¹⁸ has a substituent other than a hydrogen atom.

Examples of monovalent epoxy compounds represented by formula (IV) include epoxyethane (ethylene oxide), epoxypropane, 1,2-epoxybutane, 2,3-epoxybutane, and 3-methyl-1,2-epoxybutane. , 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-epoxyheptane, 4-methyl-1,2-epoxyheptane, 1,2-epoxyoctane, 2,3-epoxyoctane, 1,2-epoxynonane, 2,3-epoxynonane , 1,2-epoxydecane, 1,2-epoxydodecane, epoxyethylbenzene, 1-phenyl-1,2-epoxypropane, 3-phenyl-1,2-epoxypropane and the like. Examples of the monovalent epoxy compound represented by formula (V) include various alkyl glycidyl ethers. Examples of monovalent epoxy compounds represented by formula (VI) include various alkylene glycol monoglycidyl ethers. The monovalent epoxy compounds represented by formula (VII) include various alkenyl glycidyl ethers. Monovalent epoxy compounds represented by formula (VIII) include various epoxyalkanols such as glycidol. The monovalent epoxy compound represented by formula (IX) includes various epoxycycloalkanes. The monovalent epoxy compound represented by formula (X) includes various epoxycycloalkenes.

Among monovalent epoxy compounds, epoxy compounds having 2 to 8 carbon atoms are preferred. In particular, from the viewpoint of ease of handling and reactivity, the number of carbon atoms in the monovalent epoxy compound is more preferably 2-6, more preferably 2-4. Further, the monovalent epoxy compound is particularly preferably a compound represented by Formula (IV) or Formula (V). Specifically, 1,2-epoxybutane, 2,3-epoxybutane, epoxy Propane, epoxyethane or glycidol are preferred, with epoxypropane or glycidol being more preferred.

In structural unit (III), 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, such as methyl group, ethyl group, n-propyl group, Isopropyl, n-butyl, isobutyl, tert-butyl or n-pentyl groups are preferred.

The method for incorporating the structural unit (III) into EVOH (A) is not particularly limited, and examples thereof include the method described in JP-A-2014-034647.

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 is preferably 80% by mass, more preferably 90% by mass, still more preferably 95% by mass, and more preferably 97% by mass, 98% by mass, or 99% by mass. In some cases, it is even more preferable. On the other hand, the upper limit of the content of EVOH (A) may be, for example, 99.9% by mass. The content of EVOH (A) refers to the content (content ratio) in the resin composition in a dry state. The same applies to the content based on the resin composition hereinafter.

(Cinnamic acids (B))
Cinnamic acids (B) include cinnamic acid (cis-cinnamic acid, trans-cinnamic acid, or mixtures thereof) and cinnamic acid derivatives such as cinnamic acid esters and cinnamic acid salts. A cinnamic acid derivative refers to a compound or the like obtained by reacting cinnamic acid. Examples of cinnamic acid esters include methyl cinnamate and ethyl cinnamate. Cinnamates include sodium cinnamate, magnesium cinnamate, calcium cinnamate and the like. Among them, it is preferable to use cinnamic acid as the cinnamic acid (B), particularly trans-cinnamic acid from the viewpoint of stability and cost. In addition, when cinnamic acid is used, part or all of the cinnamic acid may be a cinnamate by coexisting with the aluminum salt (C).

The lower limit of the content of cinnamic acids (B) in the resin composition of the present invention is 1 ppm, preferably 3 ppm, more preferably 6 ppm, relative to EVOH (A). If the content of cinnamic acids (B) is less than 1 ppm, sufficient heat resistance and light resistance cannot be obtained, and the effects of the present invention cannot be sufficiently exhibited. On the other hand, the upper limit of the content of cinnamic acids (B) is 100 ppm relative to EVOH (A), preferably 70 ppm, more preferably 40 ppm. If the content of the cinnamic acids (B) is more than 100 ppm, problems such as the occurrence of odor and lumps may occur, and the heat resistance and light resistance may be lowered.

(Aluminum salt (C))
The aluminum salt (C) is an aluminum salt of a fatty acid having 5 or less carbon atoms, such as aluminum formate (aluminum triformate, etc.), aluminum acetate, aluminum propionate (aluminum tripropionate, etc.), aluminum butyrate (aluminum tributyrate, etc.). is mentioned. Among them, it is preferable to use aluminum acetate and/or aluminum tripropionate. Here, aluminum acetate is a general term for those having a structure of an aluminum salt of acetic acid represented by basic aluminum acetate, aluminum triacetate and the like. From the viewpoint of solubility in solvents, etc., any one or more of these may be appropriately used. Since aluminum salts of fatty acids having more than 5 carbon atoms are sparingly soluble in water, they precipitate when added during the manufacturing process, causing the generation of foreign substances.

The lower limit of the content of the aluminum salt (C) in the resin composition of the present invention is 0.08 ppm, preferably 0.2 ppm, more preferably 0.5 ppm, and 1 ppm in terms of aluminum relative to EVOH (A). It may be even more preferable. On the other hand, the upper limit of the content of aluminum salt (C) is 6 ppm, preferably 4 ppm, more preferably 3 ppm relative to EVOH (A). In the resin composition of the present invention, by containing the aluminum salt (C) together with the cinnamic acids (B), the generation of odors and lumps during melt molding is suppressed, and the resulting molded article can be used outdoors. Suppresses the occurrence of coloring and deterioration of mechanical strength during use. Although the details of why the above effect is produced by containing the aluminum salt (C) are unknown, it is presumed that it interacts with the cinnamic acids (B) and contributes to the effect of improving the heat resistance and light resistance of the cinnamic acids (B). there is If the content of the aluminum salt (C) is less than 0.08 ppm, the effect of interaction with the cinnamic acids (B) cannot be sufficiently exhibited, and excellent heat resistance and light resistance cannot be obtained. On the other hand, when the content of the aluminum salt (C) is more than 6 ppm, there is a tendency that the generation of pimples caused by aluminum and the increase in coloration become problems.

The lower limit of the molar ratio of cinnamic acids (B) to aluminum in the aluminum salt (C) (cinnamic acids (B)/aluminum) is preferably 0.7, more preferably 1, and even more preferably 2. On the other hand, the upper limit of the molar ratio (cinnamic acids (B)/aluminum) is preferably 60, more preferably 40, even more preferably 20, and even more preferably 10. The aluminum salt (C) is usually coordinated with three fatty acids having 5 or less carbon atoms centered on aluminum, and interacts with the cinnamic acids (B) having a similar structure to stabilize the cinnamic acids (B). presumed to contribute to When the molar ratio (cinnamic acids (B)/aluminum) is 0.7 or more, the relative excess of the aluminum salt (C) is suppressed, and the generation of foreign substances and the increase in coloration caused by aluminum are further suppressed. can do. On the other hand, when the molar ratio (cinnamic acids (B)/aluminum) is 60 or less, the presence of the aluminum salt (C) is relatively sufficient, so that the interaction with the cinnamic acids (B) occurs more sufficiently, It tends to have higher heat resistance and light resistance.

(other ingredients)
The resin composition of the present invention contains a resin other than EVOH (A), a metal salt other than aluminum salt (C), an acid (excluding cinnamic acid), a boron compound, and an antioxidant as long as the effects of the present invention are not impaired. , plasticizers, fillers, antiblocking agents, lubricants, stabilizers, surfactants, colorants, UV absorbers, antistatic agents, desiccants, cross-linking agents, reinforcing materials, etc., may have other components . Among them, from the viewpoint of thermal stability and adhesiveness with other resins, it is preferable to contain metal salts and/or acids (excluding cinnamic acid) other than the aluminum salt (C).

As the metal salt other than the aluminum salt (C), an alkali metal salt is preferred from the viewpoint of further enhancing interlayer adhesion, and an alkaline earth metal salt is preferred from the viewpoint of thermal stability. When the resin composition of the present invention contains such a metal salt, the content is preferably 1 ppm or more, more preferably 5 ppm or more, more preferably 10 ppm or more, further preferably 20 ppm or more in terms of metal atoms of the metal salt relative to the resin composition. Especially preferred. The content of the metal salt other than the aluminum salt (C) is preferably 10000 ppm or less, more preferably 5000 ppm or less, still more preferably 1000 ppm or less, and particularly preferably 500 ppm or less in terms of metal atoms of the metal salt relative to the resin composition. When the content of the metal salt other than the aluminum salt (C) is within the above range, the thermal stability during recycling tends to be improved while maintaining good interlayer adhesion.

As the acid (excluding cinnamic acid), carboxylic acid or phosphoric acid is preferable from the viewpoint of enhancing thermal stability during melt molding. 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, and even more preferably 50 ppm or more, relative to the resin composition. The carboxylic acid content is preferably 10000 ppm or less, more preferably 1000 ppm or less, and even more preferably 500 ppm or less. When the resin composition of the present invention contains phosphoric acid, the phosphoric acid content in the resin composition is preferably 1 ppm or more, more preferably 10 ppm or more, and even more preferably 30 ppm or more. On the other hand, the content of the phosphoric acid compound is preferably 10000 ppm or less, more preferably 1000 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 improved.

When the resin composition of the present invention contains a boron compound, its content is preferably 1 ppm or more, more preferably 10 ppm or more, and even more preferably 50 ppm or more, relative to the resin composition. Moreover, the content of the boron compound is preferably 2000 ppm or more, more preferably 1000 ppm or more, and even more preferably 500 ppm or more. When the content of the boron compound is within the above range, the thermal stability during melt molding tends to be improved.

It is preferable that the resin composition of the present invention further contains an antioxidant from the viewpoint of further reducing coloring and deterioration in strength during outdoor use. Although the type of antioxidant is not particularly limited, a compound having a hindered phenol group and a compound having a hindered amine group are preferable, and commercial products that are industrially produced and available can be used as appropriate. The content of the antioxidant is preferably 0.01 parts by mass or more and 5 parts by mass or less, more preferably 0.1 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass of EVOH (A).

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

EVOH (A) in the resin composition of the present invention, cinnamic acids (B), aluminum salt (C), metal salts other than aluminum salt (C), acids (excluding cinnamic acid), boron compounds and antioxidants other than The upper limit of the content of the component is preferably 10% by mass, and may be 1% by mass, 0.1% by mass, 0.01% by mass, or 0.001% by mass.

(Method for producing resin composition)
As a method for producing the resin composition of the present invention, for example, 1) a porous precipitate of EVOH (A) having a water content of 20 to 80% by mass is dispersed in water containing cinnamic acids (B) and aluminum salt (C). A method of bringing EVOH (A) into contact with a liquid to contain cinnamic acids (B) and aluminum salt (C) and then drying; A method of incorporating acids (B) and aluminum salt (C), extruding into a coagulating solution in the form of strands, then cutting the resulting strands into pellets and further drying; 3) EVOH (A). 4) EVOH (A), cinnamic acids (B) and aluminum salt (C) are collectively dry blended, and then 5) A method of adding cinnamic acids (B) and an aluminum salt (C) after obtaining an ethylene-vinyl acetate copolymer in the production of EVOH (A). can be done. In order to obtain the effects of the present invention more remarkably, the methods 1), 2) and 5) are preferable because they are excellent in the dispersibility of the cinnamic acids (B) and the aluminum salt (C).

In the method for preparing the resin composition obtained by the methods 1) and 2), after the cinnamic acids (B) and the aluminum salt (C) are added, and in the method 5), ethylene vinyl acetate After the copolymer is obtained, it is usually dried after passing through a saponification step and a washing step. Various drying methods can be employed as such a drying method. For example, fluidized drying in which a substantially pellet-shaped resin composition is stirred and dispersed mechanically or by hot air, or dynamic action such as stirring and dispersion of a substantially pellet-shaped resin composition. Stationary drying performed without giving is mentioned. Dryers for fluidized drying include cylindrical/groove stirring dryers, circular tube dryers, rotary dryers, fluidized bed dryers, vibrating fluidized bed dryers, conical rotary dryers, and the like. Dryers for stationary drying include batch type box dryers as materials stationary type, and band dryers, tunnel dryers, vertical dryers and the like as material transfer types. Fluidized drying and stationary drying may be combined.

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

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

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 relative to the total solid content of the resin composition of the present invention may be preferably 1% by mass, and more preferably 0.1% by mass or 0.01% by mass. When the resin composition of the present invention is in a dry state, it can exhibit good melt moldability and the like.

<Molded body>
The resin composition of the present invention can be formed into molded articles such as films, sheets, tubes, bags, containers, etc. by melt molding or the like. That is, the molded article of the present invention is a molded article molded from the resin composition of the present invention. The molded article of the present invention may be formed only from the resin composition of the present invention, or may have portions formed from other materials. For example, a multilayer structure to be described later is also one form of the molded body.

Methods for melt-molding the resin composition of the present invention include, for example, extrusion molding, cast molding, inflation extrusion molding, blow molding, melt spinning, injection molding, and injection blow molding. 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 moldings can be pulverized and molded again for the purpose of reuse. It is also possible to uniaxially or biaxially stretch films, sheets and the like.

A film, sheet, or the like, which is an example of the molded article of the present invention, can be produced by the method for producing the molded article described above. Among them, a cast molding step of melt extruding the resin composition of the present invention on a casting roll, and a step of stretching an unstretched film obtained from the resin composition (uniaxial stretching step, sequential biaxial step, simultaneous biaxial stretching step , inflation molding step) is preferred.

The average thickness of the monolayer film or sheet 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.

<Multilayer structure>
The multilayer structure of the present invention has at least one layer made of the resin composition of the present invention. The multilayer structure of the present invention usually has a layer comprising the resin composition of the present invention and a layer comprising other components. The lower limit of the number of layers in the multilayer structure of the present invention is, for example, 2, may be 3, or 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 other components include thermoplastic resins other than EVOH (A), paper, woven fabric, nonwoven fabric, metallic cotton strips, woody surfaces, and layers composed of thermoplastic resins. is preferred. The layer structure of the multilayer structure of the present invention is not particularly limited, and when a layer made of the resin composition of the present invention is represented by E, an adhesive layer by Ad, and a layer obtained from another thermoplastic resin by T, T/E Structures such as /T, E/Ad/T, T/Ad/E/Ad/T, and T/Ad/E/Ad/T can be mentioned. Each of these layers may be a single layer or multiple layers.

The method for producing the multilayer structure of the present invention is not particularly limited. A method of co-extrusion with another thermoplastic resin, a method of co-injecting the resin composition of the present invention and another thermoplastic resin, a barrier layer obtained from the resin composition of the present invention and another thermoplastic resin layer and a method of laminating them using a known adhesive such as an isocyanate compound or a polyester compound.

Other thermoplastic resins mentioned above include linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, polypropylene, propylene-α- Olefin (α-olefin having 4 to 20 carbon atoms) copolymer, polybutene, polypentene and other olefin homopolymers or their copolymers; polyester polyester elastomers such as polyethylene terephthalate, polyamides 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. Among them, 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 is preferably an adhesive resin containing a carboxylic acid-modified polyolefin. As the carboxylic acid-modified polyolefin, a modified olefin-based polymer containing a carboxyl group obtained by chemically bonding an ethylenically unsaturated carboxylic acid, its ester, or its anhydride to an olefin-based polymer can be preferably used. can. Here, the olefinic polymer means polyolefins such as polyethylene, linear low-density polyethylene, polypropylene and polybutene, and copolymers of olefins and other monomers. Among them, linear low-density polyethylene, ethylene-vinyl acetate copolymer and ethylene-ethyl acrylate copolymer are preferable, and linear low-density polyethylene and ethylene-vinyl acetate copolymer are particularly preferable.

When the multilayer structure 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 molded article and multilayer structure of the present invention are inhibited from generating odors and lumps during melt molding and the like, and are less likely to cause coloration and reduction in mechanical strength associated with outdoor use. Therefore, it is suitable for daily necessities used outdoors, packaging materials, machine parts, and the like. Examples of applications in which the features of the above molded products are particularly effective include packaging materials for food and drink, packing materials for containers, agricultural films, geomembrane, bag materials for medical infusions, high-pressure tank materials, and gasoline tanks. materials, fuel containers, tube materials for tires, cushion materials for shoes, inner bag materials for bag-in-boxes, tank materials for storing organic liquids, pipe materials for transporting organic liquids, hot water pipe materials for heating (hot water pipe materials for floor heating, etc.) ), resin wallpaper, and the like. In particular, the molded article and multilayer structure of the present invention can be suitably used as agricultural films and geomembranes, which are used outdoors and easily deteriorated by heat and light.

<Agricultural film>
The agricultural film of the present invention has at least one layer comprising the resin composition of the present invention. The agricultural film of the present invention may be a single layer film or a multilayer film. The specific structure and the like of the agricultural film of the present invention are the same as those of the film and multilayer structure as examples of the molded article described above. The average thickness of the agricultural film of the present invention is not particularly limited, and may be the same as the values exemplified as the average thickness of the single-layer or multi-layer film or sheet described above.

The agricultural film of the present invention and the multilayer structure of the present invention can be applied to various films used in the field of agriculture, such as large silo films, soil fumigation films, grain storage bags, silage films, films for vinyl houses, and mulch films. can be used. Each application will be described below.

<Large silo film>
Large silo film is a film for wrapping and preserving grain. By wrapping and storing grain in large silo film, grain can be protected from moisture, mold, insects, etc. A large silo film according to an embodiment of the present invention has at least one layer comprising the resin composition of the present invention, and has excellent gas barrier properties. The large silo film may be a single layer film or a multilayer film. The length of one side of the large silo film is, for example, 1 m or longer, and may be 2 m, 3 m, 5 m or 10 m or longer. Also, the large silo film may be processed into a bag shape or the like.

<Film for soil fumigation>
A film for soil fumigation is a film used for preventing transpiration of a soil fumigant when fumigating soil in a field or the like. A film for soil fumigation according to one embodiment of the present invention has at least one layer comprising the resin composition of the present invention, and has excellent barrier properties against soil fumigants. The soil fumigation film may be a single layer film or a multilayer film.

<Grain storage bag>
A grain storage bag is a bag for storing grain in order to protect the grain from moisture, mold, insects, etc., and is also called a Hermetic bag. A grain storage bag according to one embodiment of the present invention is obtained by forming a single-layer film or a multi-layer film having at least one layer of the resin composition of the present invention into a bag shape, bag shape, or other container shape. The average thickness of the film that constitutes the grain storage bag is not particularly limited, and may be the same value as the average thickness of the single-layer or multi-layer film or sheet described above. When the grain storage bag is, for example, a square bag, the length of one side thereof is, for example, 0.5 to 2 m.

<Silage film>
A silage film is a film used for production, packaging, etc. of silage. Silage obtained by fermenting pasture grass under anaerobic conditions is used as feed for livestock. The form of the silo using the silage film is not particularly limited, and includes various forms such as bunker silo, underground (or semi-underground) silo, bag silo, tube silo, stack silo, and wrap silo.

A silage film according to an embodiment of the present invention has at least one layer comprising the resin composition of the present invention, and has excellent gas barrier properties. The silage film may be a monolayer film or a multilayer film.

For example, when making a lap silo, grass is first formed into a desired volume (for example, 0.1 to 50 m ³ , preferably 1 to 30 m ³ ). For example, in the case of a cylindrical roll bale silo, its size is usually 0.5 to 3 m in diameter, preferably 1 to 2 m, and its height is usually 0.5 to 3 m, preferably 1 to 2 m. The silage film is then wrapped around the formed grass using a conventional wrapper to seal the grass.

<Geo-membrane>
A geomembrane is a product of a membranous structure with extremely low or impermeable water permeability, and is used as a water impermeable work, for example, in a waste treatment plant. The geomembrane of the present invention has at least one layer comprising the resin composition of the present invention and has excellent organic solvent barrier properties. The geomembrane can be a monolayer film or a multilayer film. The specific structure of the geomembrane is the same as the film and multilayer structure as examples of the molded article described above.

EXAMPLES The present invention will be specifically described below with reference to Examples, etc., but the present invention is not limited to these Examples. In addition, the methods of measurement, calculation and evaluation were in accordance with the following methods.

<Measurement of trans-cinnamic acid content>
After freezing and pulverizing the dry resin composition pellets, 22 g of pulverized material obtained by removing coarse particles with a sieve having a nominal size of 0.150 mm (100 mesh) (JIS standard Z8801-1 to 3) was filled in a Soxhlet extractor. , and 100 mL of acetone for 16 hours. The amount of trans-cinnamic acid in the resulting acetone extract was quantitatively analyzed by high performance liquid chromatography to quantify the amount of trans-cinnamic acid in the resin composition. For quantification, a calibration curve prepared using a standard of trans-cinnamic acid was used.

<Measurement of sorbic acid content>
After freezing and pulverizing the dry resin composition pellets, 22 g of pulverized material obtained by removing coarse particles with a sieve having a nominal size of 0.150 mm (100 mesh) (JIS standard Z8801-1 to 3) was filled in a Soxhlet extractor. , and 100 mL of chloroform for 16 hours. The amount of sorbic acid in the resulting chloroform extract was quantitatively analyzed by high performance liquid chromatography to quantify the amount of sorbic acid in the resin composition. For quantification, a calibration curve prepared using a standard of sorbic acid was used.

<Measurement of aluminum content>
15 g of dry resin composition pellets were weighed into a platinum crucible and subjected to dry decomposition using nitric acid and sulfuric acid. About 2 mL of hydrochloric acid was added to the incinerated sample, the volume was constant in a 50 mL volumetric flask made of polytetrafluoroethylene (PTFE), and filtered through a PTFE filter with a pore size of 0.45 μm to prepare a sample solution. Using the solution, the aluminum content (ppm) in the resin composition was obtained by high-frequency plasma emission spectrometry (ICP emission spectrometer "IRIS AP" manufactured by Jarrel Ash).

<Synthesis of EVOH (A)>
[Synthesis Example 1]
An ethylene-vinyl acetate copolymer was polymerized under the following conditions using a 250 L pressurized reactor.
Vinyl acetate 83kg
Methanol 26.6 kg
2,2′-Azobisisobutylnitrile supply amount 1119.5 mL/hr
Polymerization temperature 60°C
Polymerization tank ethylene pressure 3.8 MPa
Polymerization time 5 hours

The polymerization conversion rate of vinyl acetate in the obtained copolymerization reaction solution was about 40%. A methanol solution of trans-cinnamic acid was added to this copolymerization reaction solution so that the amount of trans-cinnamic acid was 130 ppm with respect to the charged vinyl acetate. After that, the copolymerization reaction liquid is supplied to a stripping column, and unreacted vinyl acetate is removed from the top of the column by introducing methanol vapor from the bottom of the column to obtain an ethylene-vinyl acetate copolymer having an ethylene content of 32 mol %. to obtain a 41% by mass methanol solution. This ethylene-vinyl acetate copolymer methanol solution was charged into a saponification reactor, and a sodium hydroxide/methanol solution (80 g/L) was added so as to have an equivalent weight of 0.4 with respect to the vinyl ester unit in the copolymer. After adjusting the copolymer concentration to 20% by mass by adding methanol, the temperature was raised to 60° C., and the saponification reaction was performed for about 4 hours while nitrogen gas was blown into the reactor. . The obtained saponification reaction liquid is extruded into water through a metal plate having a circular opening to precipitate, cut into pellets, deliquoring in a centrifuge, and then add a large amount of water to deliquoring. After repeated washing, pellets having a diameter of about 3 m and a length of about 5 mm were obtained. A part of the obtained pellets was frozen in a freezer at -80 ° C., freeze-dried with a vacuum dryer to obtain freeze-dried pellets, and YI (yellowness, yellow index) was measured according to JIS-K-7103. By the way, YI was 11.

[Synthesis Example 2]
After the polymerization, instead of the methanol solution of trans-cinnamic acid, a methanol solution of trans-cinnamic acid and basic aluminum acetate was charged so that trans-cinnamic acid was 130 ppm and basic aluminum acetate was 8 ppm relative to vinyl acetate. Polymerization, saponification, pelletization and washing were carried out in the same manner as in Synthesis Example 1 except for the addition to obtain pellets. After freezing a part of the obtained pellets in a freezer at -80 ° C., the YI of the freeze-dried pellets obtained by freeze-drying with a vacuum dryer was measured according to JIS-K-7103. Met.

[Synthesis Example 3]
After the polymerization, instead of the methanol solution of trans-cinnamic acid, a methanol solution of sorbic acid and basic aluminum acetate was added so that 100 ppm of sorbic acid and 8 ppm of basic aluminum acetate relative to vinyl acetate were added. Polymerization, saponification, pelletization and washing were carried out in the same manner as in Synthesis Example 1 to obtain pellets. After freezing a part of the obtained pellets in a freezer at -80 ° C., the YI of the freeze-dried pellets obtained by freeze-drying with a vacuum dryer was measured according to JIS-K-7103. YI was 12. Met.

[Synthesis Example 4]
Synthesis Example 1 was repeated except that the ethylene pressure in the polymerization tank was 3.2 MPa and the polymerization time was 4 hours and 40 minutes. A copolymerization reaction liquid containing a copolymer was obtained. Instead of the methanol solution of trans-cinnamic acid, a methanol solution of trans-cinnamic acid and basic aluminum acetate was added to this copolymerization reaction solution, and trans-cinnamic acid was 130 ppm and basic aluminum acetate was 8 ppm relative to vinyl acetate. After that, saponification, pelletization and washing were performed in the same manner as in Synthesis Example 1 to obtain pellets. After freezing a part of the obtained pellets in a freezer at -80 ° C., the YI of the freeze-dried pellets obtained by freeze-drying with a vacuum dryer was measured according to JIS-K-7103. YI was 8. rice field.

[Synthesis Example 5]
Synthesis Example 1 was repeated except that the ethylene pressure in the polymerization tank was 5.2 MPa and the polymerization time was 6 hours. A copolymerization reaction solution containing coalescence was obtained. Instead of the methanol solution of trans-cinnamic acid, a methanol solution of trans-cinnamic acid and basic aluminum acetate was added to this copolymerization reaction solution, and trans-cinnamic acid was 130 ppm and basic aluminum acetate was 8 ppm relative to vinyl acetate. Polymerization, saponification, pelletization and washing were carried out in the same manner as in Synthesis Example 1, except that the amount was added to obtain pellets. After freezing a part of the obtained pellets in a freezer at -80 ° C., the YI of the freeze-dried pellets obtained by freeze-drying with a vacuum dryer was measured according to JIS-K-7103. YI was 6. rice field.

<Preparation of resin composition>
[Examples 1 to 12 and Comparative Examples 2 to 4]
20 kg of the pellets obtained by deliquoring in Synthesis Example 2 were placed in 180 kg of a mixed solvent of water/methanol=40/60 (mass ratio) and stirred at 60° C. for 6 hours to completely dissolve. Trans-cinnamic acid and aluminum triacetate were added to the resulting solution, and the mixture was further stirred for 1 hour to completely dissolve the trans-cinnamic acid and aluminum triacetate to obtain a resin composition solution. This resin composition solution is continuously extruded from a nozzle with a diameter of 4 mm into a coagulation bath of water/methanol=90/10 (mass ratio) adjusted to 0° C. to coagulate into strands, and then introduced into a pelletizer. A resin composition chip was obtained. After washing the obtained resin composition chips with an acetic acid aqueous solution and ion-exchanged water, they were immersed in an aqueous solution containing acetic acid, sodium acetate, potassium dihydrogen phosphate and boric acid. After the resin composition chips were deliquored, they were dried at 80° C. for 4 hours using a hot air dryer and then at 100° C. for 16 hours to obtain a resin composition (dry resin composition pellets). The content of each component in the obtained resin composition was quantified using the above quantification method. By adjusting the amount of trans-cinnamic acid and aluminum triacetate added and the concentration of each component in the aqueous solution for immersion treatment, the resin composition was prepared so that the content of each component was as shown in Table 1. prepared. The content of each component in Table 1 is based on the amount of EVOH. In addition, "-" in Table 1 indicates that the corresponding component is not contained.

[Example 13]
A resin composition (dry resin composition pellets) was obtained under the same conditions as in Example 1, except that the pellets obtained by deliquoring in Synthesis Example 4 were used. Table 1 shows the quantitative results of the content of each component in the obtained resin composition.

[Example 14]
A resin composition (dry resin composition pellets) was obtained under the same conditions as in Example 1, except that the pellets obtained by deliquoring in Synthesis Example 5 were used. Table 1 shows the quantitative results of the content of each component in the obtained resin composition.

[Comparative Example 1]
The pellets obtained by deliquoring in Synthesis Example 1 were washed with an acetic acid aqueous solution and deionized water, and then immersed in an aqueous solution containing acetic acid, sodium acetate, potassium dihydrogen phosphate and boric acid. After the resin composition chips were deliquored, they were dried at 80° C. for 4 hours using a hot air dryer and then at 100° C. for 16 hours to obtain a resin composition (dry resin composition pellets). Table 1 shows the quantitative results of the content of each component in the obtained resin composition.

[Comparative Example 5]
20 kg of the pellets obtained by deliquoring in Synthesis Example 3 were placed in 180 kg of a mixed solvent of water/methanol=40/60 (mass ratio) and stirred at 60° C. for 6 hours to completely dissolve. Sorbic acid and aluminum triacetate were added to the resulting solution, and the mixture was further stirred for 1 hour to completely dissolve the sorbic acid and aluminum triacetate to obtain a resin composition solution. This resin composition solution is continuously extruded from a nozzle with a diameter of 4 mm into a coagulation bath of water/methanol=90/10 (mass ratio) adjusted to 0° C. to coagulate into strands, and then introduced into a pelletizer. A resin composition chip was obtained. After washing the obtained resin composition chips with an acetic acid aqueous solution and ion-exchanged water, they were immersed in an aqueous solution containing acetic acid, sodium acetate, potassium dihydrogen phosphate and boric acid. After the resin composition chips were deliquored, they were dried at 80° C. for 4 hours using a hot air dryer and then at 100° C. for 16 hours to obtain a resin composition (dry resin composition pellets). The content of each component in the obtained resin composition was quantified using the above quantification method. By adjusting the amount of sorbic acid and aluminum triacetate added and the concentration of each component in the aqueous solution for immersion treatment, a resin composition was prepared so that the content of each component was as shown in Table 1.

Each resin composition obtained in the above examples and comparative examples was formed into a film under the following conditions to obtain a single layer film having a thickness of 20 μm.
・Extruder: Single-screw extruder (Laboplastomill, manufactured by Toyo Seiki Seisakusho), 20 mmφ
・Set temperature: C1/C2/C3/D = 180°C/210°C/210°C/210°C

<Odor evaluation>
The presence or absence of odor was checked during film molding and after standing in an atmosphere of 150° C. for 5 hours. The evaluation was carried out on 5 subjects, and the results were evaluated according to the following 3-grade evaluation, and the average value was obtained.
1: No odor in any case 2: Slight odor in any case 3: Definite odor in any case The determined average value was evaluated by the following A to C. Table 1 shows the evaluation results.
A: less than 1.5 B: 1.5 or more and less than 2.5 C: 2.5 or more

<Evaluation of pimples>
Gel-like spots (those with a size of 150 μm or more that can be seen with the naked eye) on the resulting film were counted and converted to per 1.0 m ² . The number of lumps per 1.0 m ² was judged as follows. Table 1 shows the evaluation results.
A: Less than 20 B: 20 or more and less than 40 C: 40 or more

<Heat resistance/light resistance test>
The resulting film was tested for accelerated heat resistance for 8 hours using an eye super UV tester (SUV W-151, manufactured by Iwasaki Electric) under the conditions of an irradiance of 1000 W/m ² , a black panel temperature of 63°C, and a relative humidity of 50%. - A light fastness test was performed. It was evaluated by obtaining the breaking elongation before and after the test, the YI change amount before and after the test, and the breaking elongation reduction rate before and after the test. The elongation at break represents the difficulty of breaking against tension. Therefore, the rate of decrease in elongation at break was used as an index indicating that the decrease in mechanical strength is small. YI measurement and tensile test were performed by the following methods. Table 1 shows the evaluation test results.

<YI measurement>
A color difference meter (NF-902, manufactured by Nippon Denshoku Industries) was used. When the YI of the film before the accelerated heat resistance/light resistance test was YI ₀ and the YI of the film after the test was YI ₁ , ΔYI was determined by the following formula. When ΔYI became a negative value, ΔYI was set to 0.
ΔYI=YI ₁ -YI ₀

<Tensile test>
The elongation at break was evaluated using an autograph (AGS-H, manufactured by Shimadzu Corporation) under the conditions of a temperature of 23° C., a relative humidity of 50% RH, and a tensile speed of 500 mm/min. A test piece cut into a size of 50 mm long and 15 mm wide was used.

As shown in Table 1, in Examples 1 to 14, the odor evaluation was A or B, and the particle generation evaluation was A or B, indicating that the odor and the generation of pores were suppressed. In Examples 1 to 14, the amount of change in YI (ΔYI) before and after the heat resistance/light resistance test was 0.5 or less, and the rate of decrease in breaking elongation was 35% or less. It can be seen that a molded article with less occurrence of coloring and less decrease in mechanical strength is obtained.

[Example 15]
100 parts by mass of the resin composition of Example 4 and 1 part by mass of TINUVIN NOR 371 (manufactured by BASF Japan Ltd.: hindered amine compound) having an N-alkoxy-2,2,6,6-tetraalkylpiperidine structure as an antioxidant. After dry blending, they were melt-kneaded to prepare resin composition pellets.

[Example 16] Preparation of silage film Using the resin composition pellets prepared in Example 15 and the following resin composition, a film was formed under the following conditions, and the trim was cut to form a silage film having a width of 500 mm and a total thickness of 25.5 µm. was made.
・Apparatus: 7 types of 7-layer blown film forming machine (manufactured by Brampton)
・Layer structure and thickness of each layer:
Outer layer 1/outer layer 2/adhesive resin layer 1/resin composition layer/adhesive resin layer 2/outer layer 3/outer layer 4
Outer layers 1 and 4: Melt-kneaded product of 97% by mass of linear low-density polyethylene (TUFLIN HS-7028 NT7 (MFR 1.0 g/10 min) manufactured by Dow Chemical Co., Ltd.) and 3% by mass of polyisobutene (PB32, manufactured by Soltex) 6 μm each
Outer layers 2 and 3: Melt-kneaded product of 90% by mass of linear low-density polyethylene (TUFLIN HS-7028 NT7 (MFR 1.0 g/10 min) manufactured by Dow Chemical Co.) and 10% by mass of polyisobutene (PB32 manufactured by Soltex) 4 μm each
Adhesive resin layers 1 and 2: Maleic anhydride-modified linear low-density polyethylene (Admer NF498, manufactured by Mitsui Chemicals, Inc.) 2 μm each
・Resin composition layer: 1.5 μm
[Film forming conditions]
Extruder/Extruder 1: 45 mmφ single screw extruder (L/D = 24) ... outer layer 1
・ Extruder 2: 30 mmφ single screw extruder (L / D = 24) ... outer layer 2
・ Extruder 3: 30 mmφ single screw extruder (L / D = 24) ... outer layer 3
・ Extruder 4: 45 mmφ single screw extruder (L / D = 24) ... outer layer 4
・ Extruder 5: 30 mmφ single screw extruder (L / D = 24) ... adhesive resin layer 1
・ Extruder 6: 30 mmφ single screw extruder (L / D = 24) ... adhesive resin layer 2
- Extruder 7: 30 mmφ single screw extruder (L/D = 20) ... Resin composition layer set temperature and rotation speed:
- Extruders 1 and 4: C1/C2/C3/A = 180°C/190°C/205°C/205°C, 27 rpm
- Extruders 2 and 3: C1/C2/C3/A = 180°C/190°C/205°C/205°C, 69 rpm
- Extruders 5 and 6: C1/C2/C3/A = 190°C/225°C/215°C/220°C, 26 rpm
- Extruder 7: C1/C2/C3/A = 180°C/210°C/215°C/220°C, 19 rpm
・Die: 150mm, set temperature 220℃
・Stretching ratio (Blow up rate): 3.09

<Lapping test>
Using the obtained silage film and a remote control wrapping machine WM1600R (manufactured by Takakita Co., Ltd.), pasture grass shaped to a size of φ120 cm×120 cm was wrapped. The resulting silage film was able to wrap pasture grass well and was confirmed to be suitable as a silage film.

[Example 17] Preparation of soil fumigation film Using the resin composition pellets prepared in Example 15 and the following resin composition, extruders 1 and 2 extruded the resin composition constituting outer layer A into extruder 3, 4, the resin composition forming the outer layer D, the resin composition forming the adhesive resin layers B and C using the extruders 5 and 6, and the resin composition forming the resin composition layer using the extruder 7. A soil fumigation film having a width of 1,400 mm and a total thickness of 35 μm was prepared by cutting the trim under the same conditions as the silage film production conditions of Example 16, except that the silage films were extruded.
・Layer structure and thickness of each layer:
Outer layer A/adhesive resin layer B/resin composition layer/adhesive resin layer C/outer layer D
(resin used)
LLDPE: SCLAIR FP120-A (manufactured by NOVA Chemicals)
mLLDPE: ELITE5401G (manufactured by Dow Chemical)
Black MB: Ampacet 190580 (manufactured by Ampacet)
White MB: Ampacet 112122 (manufactured by Ampacet)
UVI MB: Ampacet 100840 (manufactured by Ampacet)
Slip MBAmpacet 10090 (manufactured by Ampacet)
Outer layer A: LLDPE/mLLDPE/black MB/UVI MB/Slip MB = 68/20/10/4/4 mass% melt-kneaded product Extruder 1: 10 µm, Extruder 2: 4.5 µm Total: 14.5 µm
Outer layer D: LLDPE/mLLDPE/white MB/UVI MB/Slip MB = 68/20/10/4/4 mass% melt-kneaded product Extruder 3: 10 µm, Extruder 4: 4.5 µm Total: 14.5 µm
・ Adhesive resin layers B and C: Admer AT2474A (manufactured by Mitsui Chemicals, Inc.) 2 μm each
・Resin composition layer: 2 μm

<Unwinding resistance test>
The soil fumigation film is stretched and unwound from a film roll to a field, and after use, is rewound on the film roll for repeated use. Film breakage was evaluated after unwinding and unwinding the soil fumigation film 100 times.

[Example 18] Preparation of grain storage bag Using the resin composition pellets prepared in Example 15 and the following resin, extruders 1 and 2 extruders 1 and 2 to form the outer layer A, extruders 3 and 4 to form the outer layer D , the adhesive resin layers B and C are extruded through extruders 5 and 6, and the resin composition layer is extruded through extruder 7, and the die is 75 mm and the stretching ratio is 1. A grain storage bag film having a width of 900 mm and a total thickness of 230 μm was produced by cutting the trim in the same manner as the silage film production conditions of Example 16, except that 5 was used. A bag of 400 mm×700 mm was made from the obtained film and used as a grain storage bag.
・Layer structure and thickness of each layer:
Outer layer A/adhesive resin layer B/resin composition layer/adhesive resin layer C/outer layer D
(resin used)
Outer layers A, D: LLDPE; SCLAIR FP120-A (manufactured by NOVA Chemicals) Extruders 1 and 3: 50 μm each, Extruders 2 and 4: 47 μm each Total: 97 μm each
・ Adhesive resin layers B and C: Admer NF498A (manufactured by Mitsui Chemicals, Inc.) 12 μm each
・Resin composition layer: 12 μm

<Germination test>
The resulting grain storage bag was filled with 50 kg of corn and stored outdoors for 180 days. After storage, the germination power of the corn was evaluated. The germinating power of the corn after storage was comparable to that of the corn before storage.

[Example 19] Preparation of geomembrane Using the resin composition pellets prepared in Example 15 and the following resins, extruders 1 and 2 were used to form the outer layer A, and extruders 3 and 4 were used to form the outer layer D. The grain storage of Example 18 except that the resins constituting the adhesive resin layers B and C were extruded by the extruders 5 and 6, and the resins constituting the resin composition layer were extruded by the extruder 7. A geomembrane having a width of 225 mm and a total thickness of 500 μm was produced by cutting the trim in the same manner as the bag manufacturing conditions.
・Layer structure and thickness of each layer:
Outer layer A/adhesive resin layer B/resin composition layer/adhesive resin layer C/outer layer D
(resin used)
Outer layers A, D: LLDPE; SCLAIR FP120-A (manufactured by NOVA Chemicals) Extruders 1 and 3: 110 μm each, Extruders 2 and 4: 110 μm each Total: 220 μm each
- Adhesive resin layers B and C: Admer AT2474A (manufactured by Mitsui Chemicals, Inc.) 20 μm each
・Resin composition layer: 20 μm

<Landfill test>
Two holes of 50 cm×50 cm wide and 30 cm deep were dug in the ground, covered with dust, one hole was covered with a 500 μm polyethylene film and the other hole was covered with the resulting geomembrane. After 30 days, the surrounding odor was evaluated. An odor was felt around the polyethylene film, but not around the geomembrane.

EFFECTS OF THE INVENTION The resin composition of the present invention suppresses the generation of odors and lumps during molding, and can provide molded articles with suppressed coloration and reduced strength even when used outdoors. Therefore, the resin composition of the present invention is useful as a molding material for various molded articles, multilayer structures, and the like.

Claims (7)

An ethylene-vinyl alcohol copolymer (A), a cinnamic acid (B), and an aluminum salt (C) of a fatty acid having 5 or less carbon atoms, wherein the cinnamic acid (B) is added to the ethylene-vinyl alcohol copolymer (A). The content is 1 to 100 ppm, the content of the aluminum salt of a fatty acid having 5 or less carbon atoms (C) with respect to the ethylene-vinyl alcohol copolymer (A) is 0.08 to 6 ppm in terms of aluminum, and the carbon A resin composition wherein the aluminum salt (C) of a fatty acid of number 5 or less is aluminum acetate and/or aluminum propionate . The resin according to claim 1, wherein the molar ratio of the cinnamic acids (B) to the aluminum in the aluminum salt (C) of a fatty acid having 5 or less carbon atoms (cinnamic acids (B)/aluminum) is 0.7 to 60. Composition. A molded article molded from the resin composition according to claim 1 or 2 . A multilayer structure comprising at least one layer comprising the resin composition according to claim 1 or 2 . An agricultural film comprising at least one layer comprising the resin composition according to claim 1 or 2 . 5. A multi-layer structure according to claim 4 for use in large silo films, soil fumigation films, grain storage bags or silage films. A geomembrane having at least one layer comprising the resin composition according to claim 1 or 2 .