Ethylene-vinyl alcohol copolymer resin composition having weather resistance

Abstract

To provide a resin composition containing EVOH which has such weather resistance as to maintain impact strength and light transmittance even after long-term outdoor use and can suppress coloring of an obtained film, a laminate, an industrial film, and a pipe, and a production method for the resin composition and a master batch used in the production method.SOLUTION: A resin composition contains EVOH (A) having an ethylene unit content of 20-60 mol%, a hindered amine-based compound (B) which has a 2,2,6,6-tetraalkylpiperidine ring structure and has an alkoxy group coupled to a nitrogen atom in the structure, and a benzotriazole-based compound (C), and contains, with respect to 100 pts.mass of the EVOH (A), 0.2-5 pts.mass of the hindered amine-based compound (B) and 0.1-5 pts.mass of the benzotriazole-based compound (C).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resin composition containing an ethylene-vinyl alcohol copolymer, a laminate, an industrial film, and a pipe, as well as a method for producing the resin composition and a masterbatch used in the production method. [Background technology]

[0002] In general, ethylene-vinyl alcohol copolymers (hereinafter sometimes abbreviated as "EVOH") are excellent in transparency, gas barrier properties, aroma retention, solvent resistance, oil resistance, etc., and are used by making use of such properties in films and sheets for food packaging materials, pharmaceutical packaging materials, industrial chemical packaging materials, pesticide packaging materials, etc., or containers such as bottles. In addition, by making use of its barrier properties, heat retention, and contamination resistance, it is also widely used in applications such as industrial films and pipes. However, in applications such as these industrial films and pipes, they are often exposed to ultraviolet rays (sunlight) or chemicals such as pesticides for long periods of time, and there is concern about the deterioration of the physical properties of EVOH (mechanical strength, gas barrier properties, anti-fogging properties, etc.) due to light and chemicals. In order to suppress such deterioration of physical properties, for example, Patent Document 1 describes blending a hindered amine compound and a hindered phenol compound having a specific structure with EVOH. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 052014 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for EVOH resin compositions with higher weather resistance, and even if a resin composition in which a hindered amine compound and a hindered phenol compound having a specific structure are blended with EVOH is used as in the above-mentioned conventional technology, the weather resistance may be insufficient. In particular, when used outdoors for a long period of time, it is important that mechanical properties such as impact strength can be maintained after long-term outdoor use, but the above-mentioned conventional technology may not be able to maintain the impact strength after long-term outdoor use. In addition, when a large amount of additives is used for the purpose of increasing weather resistance in order to maintain impact strength, coloring of the film becomes a problem, and it has been found that it is difficult to maintain impact strength and suppress coloring of the film at the same time. Furthermore, for example, when a roll of film is stored outdoors, deterioration of the film inside the roll can be more efficiently suppressed by keeping the light transmittance of ultraviolet light (e.g., 300 nm) low, but it has been found that the above-mentioned conventional technology increases the light transmittance of ultraviolet light after long-term outdoor use.

[0005] The present invention has been made to solve the above problems, and an object of the present invention is to provide a resin composition containing EVOH that has weather resistance sufficient to maintain impact strength and light transmittance even after long-term outdoor use and is capable of suppressing discoloration of the resulting film, a laminate, an industrial film, and a pipe, as well as a method for producing the resin composition and a masterbatch used in the production method. [Means for solving the problem]

[0006] According to the present invention, the above object is [1] A resin composition comprising an ethylene-vinyl alcohol copolymer (A) having an ethylene unit content of 20 to 60 mol% (hereinafter may be abbreviated as "EVOH (A)"), a hindered amine compound (B) having a 2,2,6,6-tetraalkylpiperidine ring structure and having an alkoxy group bonded to a nitrogen atom in the structure (hereinafter may be abbreviated simply as "hindered amine compound (B)"), and a benzotriazole compound (C), in which the resin composition contains 0.2 to 5 parts by mass of the hindered amine compound (B) and 0.1 to 5 parts by mass of the benzotriazole compound (C) relative to 100 parts by mass of the EVOH (A); [2] The resin composition according to [1], wherein the mass ratio (C) / (B) of the benzotriazole compound (C) to the hindered amine compound (B) is 0.2 to 3.5; [3] The resin composition according to [1] or [2], wherein the molecular weight of the hindered amine compound (B) is 1,000 or more; [4] The resin composition according to any one of [1] to [3], wherein the benzotriazole compound (C) has an aromatic ring having a hydroxyl group bonded thereto, and the aromatic ring has a structure bonded to a nitrogen atom constituting a benzotriazole ring; [5] The resin composition according to [4], wherein the aromatic ring to which the hydroxyl group is bonded has two or more substituents other than the benzotriazole ring and the hydroxyl group; [6] The resin composition according to any one of [1] to [5], wherein the benzotriazole compound (C) has a halogen group on the benzotriazole ring; [7] The resin composition according to any one of [1] to [6], further containing phosphate ions in an amount of 5 ppm or more and 200 ppm or less, and alkali metal ions in an amount of 10 ppm or more and 400 ppm or less; [8] The resin composition according to any one of [1] to [7], further containing a boron compound in an amount of 50 to 400 ppm in terms of elemental boron; [9] Any of the resin compositions of [1] to [8], wherein a film having a thickness of 100 μm made of the resin composition of any of [1] to [8] has a light transmittance at a wavelength of 300 nm, as measured in accordance with JIS K 7361-1:1997, of 50% or less;

[11] For a film having a thickness of 100 μm made of any one of the resin compositions of [1] to [9], the light transmittance at a wavelength of 300 nm measured in accordance with JIS K 7361-1:1997 is 63°C, 50% RH, and irradiation intensity of 1000 W / m 2 any of the resin compositions of [1] to [9], in which the difference in light transmittance before and after a weather resistance test in which the composition is irradiated with light at 400 K for 50 hours (the transmittance (%) after the weather resistance test) - (the transmittance (%) before the weather resistance test) is 4.0% or less;

[11] A laminate comprising a layer made of the resin composition according to any one of [1] to [8];

[12] Industrial films containing any one of the laminates [9] to

[11] ;

[13] [9]-

[11] containing any of the laminates;

[14] A masterbatch for producing the resin composition according to any one of the items [1] to [8], comprising EVOH (A), a hindered amine compound (B), and a benzotriazole compound (C), the masterbatch containing 2 to 20 parts by mass of the EVOH (B) and 1 to 15 parts by mass of the benzotriazole compound (C) per 100 parts by mass of the EVOH (A);

[15] A method for producing a resin composition, comprising: a step of melt-kneading 100 parts by mass of EVOH (A), 2 to 20 parts by mass of a hindered amine compound (B), and 1 to 15 parts by mass of a benzotriazole compound (C) to obtain a master batch; and a step of melt-kneading the obtained master batch with EVOH (A) to obtain a resin composition containing 0.2 to 5 parts by mass of the hindered amine compound (B) and 0.1 to 5 parts by mass of the benzotriazole compound (C) relative to 100 parts by mass of the EVOH (A); This is achieved by providing Effect of the Invention

[0007] Effects of the Invention The present invention provides a resin composition, laminate, industrial film, and pipe containing EVOH, which has weather resistance that enables impact strength and light transmittance to be maintained even after long-term outdoor use and can suppress discoloration of the resulting film, as well as a method for producing the resin composition and a masterbatch for use in the production method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The resin composition of the present invention is a resin composition containing EVOH (A), a hindered amine compound (B), and a benzotriazole compound (C), and contains 0.2 to 5 parts by mass of the hindered amine compound (B) and 0.1 to 5 parts by mass of the benzotriazole compound (C) relative to 100 parts by mass of EVOH (A). When the resin composition of the present invention contains the hindered amine compound (B), the film tends to be prevented from deteriorating in hue after long-term outdoor use, while the light transmittance at 300 nm after long-term outdoor use tends to increase significantly. In addition, when the resin composition contains the benzotriazole compound (C), the light transmittance at 300 nm can be reduced, and the increase in the light transmittance at 300 nm after long-term outdoor use can be suppressed, while the hue of the film tends to deteriorate after long-term outdoor use. Furthermore, by containing a specific amount of the hindered amine compound (B) and the benzotriazole compound (C) in the resin composition of the present invention, it is surprisingly possible to significantly suppress the increase in light transmittance at 300 nm after long-term outdoor use without deteriorating the hue of the film after long-term outdoor use, and furthermore, there is a tendency to suppress the decrease in impact strength after long-term outdoor use. The reason why the decrease in impact strength can be suppressed is unclear, but when the specific amount of the hindered amine compound (B) and the benzotriazole compound (C) is contained, the decrease in molecular weight of EVOH (A) after weather resistance test is significantly suppressed, and when only one of the hindered amine compound (B) or the benzotriazole compound (C) is contained, the decrease in molecular weight is not suppressed very much, so it is presumed that the synergistic effect of the hindered amine compound (B) and the benzotriazole compound (C) suppresses the decrease in molecular weight and suppresses the decrease in impact strength. In addition, since the resin composition of the present invention can also suppress the decrease in barrier property after long-term outdoor use, for example, even if it is used for the purpose of suppressing the migration of pesticides, etc., its function can be maintained for a long period of time. The barrier property can be indirectly evaluated by the oxygen permeability measured in accordance with JIS K 7126:2006 (isobaric method).

[0009] In this specification, since weather resistance tests are conducted to evaluate the physical properties after long-term outdoor use, "after long-term outdoor use" may be expressed as "after weather resistance test". Also, "light transmittance at 300 nm" may be expressed as "light transmittance (300 nm)". Also, the property of being able to suppress the increase in light transmittance (300 nm) and the decrease in impact strength after a weather resistance test may be expressed as weather resistance.

[0010] [EVOH(A)] The resin composition of the present invention contains EVOH (A) having an ethylene unit content of 20 to 60 mol %. EVOH (A) is a copolymer having ethylene units and vinyl alcohol units, and is obtained, for example, by saponifying a copolymer containing ethylene and a vinyl ester using an alkali catalyst or the like. A representative vinyl ester is vinyl acetate, but other fatty acid vinyl esters (vinyl formate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate, vinyl versatate, etc.) can also be used.

[0011] The lower limit of the ethylene unit content of EVOH (A) is 20 mol%, preferably 23 mol%, more preferably 25 mol%, and even more preferably 27 mol%. The upper limit of the ethylene unit content of EVOH (A) is 60 mol%, preferably 55 mol%, and more preferably 50 mol%. If the ethylene unit content is less than the lower limit, the melt moldability of the resin composition may be reduced. Conversely, if the ethylene unit content exceeds the upper limit, the gas barrier properties of the resulting industrial and agricultural films, pipes, etc. may be reduced. The ethylene unit content of EVOH (A) is: 1 It can be determined by H-NMR measurement.

[0012] The lower limit of the saponification degree of EVOH (A) is preferably 90 mol%, more preferably 95 mol%, and even more preferably 99 mol%. When the saponification degree of EVOH (A) is equal to or higher than the lower limit, the gas barrier properties of the resulting laminate or the like are improved. The saponification degree means the ratio of the number of vinyl alcohol units to the total number of vinyl alcohol units and vinyl ester units in EVOH (A). The upper limit of the saponification degree may be 99.99 mol%. The saponification degree of EVOH (A) is 1 It can be determined by H-NMR measurement.

[0013] EVOH (A) may contain other monomer units other than ethylene, vinyl ester and vinyl alcohol, so long as the effects of the present invention are not impaired. In particular, by introducing a modified group containing a primary hydroxyl group having a specific structure, it may be possible to achieve a high level of both gas barrier properties and moldability of EVOH (A). The content of other monomer units is preferably 10 mol% or less, more preferably 5 mol% or less, even more preferably 1 mol% or less, and particularly preferably substantially none. Examples of such other monomers include alkenes such as propylene, butylene, pentene, and hexene; 3-acyloxy-1-propene, 3-acyloxy-1-butene, 4-acyloxy-1-butene, 3,4-diacyloxy-1-butene, 3-acyloxy-4-methyl-1-butene, 4-acyloxy-1-butene, 3,4-diacyloxy-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-acyloxy-1-pentene, 5-acyloxy-1-pentene, 4,5-diacyloxy-1-pentene, 4-acyloxy-1-hexene, 5-acyloxy-1-hexene, 6-acyloxy-1-hexene, 5,6-diacyloxy ester group-containing alkenes or saponification products thereof, such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, or other unsaturated acids or their anhydrides, salts, or mono- or dialkyl esters; nitriles such as acrylonitrile and methacrylonitrile; amides such as acrylamide and methacrylamide; olefin sulfonic acids or salts thereof, such as vinyl sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid; vinyl silane compounds such as vinyl trimethoxy silane, vinyl triethoxy silane, vinyl tri(β-methoxy-ethoxy) silane, and γ-methacryloxypropyl methoxy silane; alkyl vinyl ethers, vinyl ketones, N-vinyl pyrrolidone, vinyl chloride, and vinylidene chloride.

[0014] EVOH (A) may be modified as necessary by urethanization, acetalization, cyanoethylation, oxyalkylenation, etc. Oxyalkylenation can be carried out using an epoxy compound, such as epoxyethane (ethylene oxide), epoxypropane, 1,2-epoxybutane, 2,3-epoxybutane, 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, Examples of such epoxy alkanols include 2-epoxyoctane, 2,3-epoxyoctane, 1,2-epoxynonane, 2,3-epoxynonane, 1,2-epoxydecane, 1,2-epoxydodecane, epoxyethylbenzene, 1-phenyl-1,2-propane, 3-phenyl-1,2-epoxypropane, various alkyl glycidyl ethers, various alkylene glycol monoglycidyl ethers, various alkenyl glycidyl ethers, various epoxy alkanols such as glycidol, various epoxy cycloalkanes, and various epoxy cycloalkenes. Among these, 1,2-epoxybutane, 2,3-epoxybutane, epoxypropane, epoxyethane, or glycidol is preferred, and epoxypropane or glycidol is more preferred.

[0015] The melt flow rate (MFR) of EVOH (A) (190°C, under a load of 2160 g) is preferably 0.1 to 30 g / 10 min, more preferably 0.3 to 25 g / 10 min, and even more preferably 0.5 to 20 g / 10 min. However, for those having a melting point near or exceeding 190°C, the MFR is measured under a load of 2160 g at multiple temperatures equal to or higher than the melting point, and is plotted on a semi-logarithmic graph with the reciprocal of absolute temperature on the horizontal axis and the logarithm of MFR on the vertical axis, and expressed as a value extrapolated to 190°C.

[0016] The EVOH (A) may be used alone or in combination of two or more kinds.

[0017] [Hindered amine compounds (B)] The resin composition of the present invention contains 0.2 to 5 parts by mass of a hindered amine compound (B) relative to 100 parts by mass of EVOH (A). By containing the hindered amine compound (B) in the resin composition of the present invention, the deterioration of color after a weather resistance test tends to be suppressed, and by using it in combination with a benzotriazole compound (C) described later, the weather resistance becomes significantly good. The hindered amine compound (B) has a 2,2,6,6-tetraalkylpiperidine ring structure and has an alkoxy group bonded to a nitrogen atom in the structure. As the hindered amine compound (B), commercially available products can be used, such as TINUVIN NOR 371 (manufactured by BASF Japan Ltd., general formula (IV) below, molecular weight: 2800 to 4000), Hostavin NOW (manufactured by Clariant, chemical formula: general formula (I) below, molecular weight: about 2000), FLAMESTAB NOR 116 (manufactured by BASF Japan Ltd., chemical formula: general formula (II) below, molecular weight: 2261), Chimassorb 2020 (manufactured by BASF Japan Ltd., 1,6-Hexanediamine, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-polymer with 2,4,6-trichloro-1,3,5-triazine, reaction products with N-butyl-1-butanamine and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, molecular weight: 2600 to 3400), and particularly preferred is TINUVIN NOR 371. These hindered amine compounds (B) may be used alone or in combination of two or more kinds.

[0018] [ka]

[0019] (In the above general formula (I), R 1 is an alkyl group having 1 to 24 carbon atoms or an alkenyl group having 2 to 24 carbon atoms.

[0020] [ka]

[0021] (R in the above general formula (II) 2 is a substituent represented by the following general formula (III), and the binding site is on the triazine ring.

[0022] [ka]

[0023] [ka]

[0024] (R in the above general formula (IV) 3 ~R 7 are optional substituents, and each may be different or the same, or only some of the substituents may be the same.

[0025] The molecular weight of the hindered amine compound (B) is preferably 1000 or more. When the molecular weight is 1000 or more, the bleeding out and volatilization of the hindered amine compound (B) after long-term outdoor use can be suppressed, and weather resistance tends to be maintained for a long time. In addition, when the resin composition of the present invention is melt-molded to form a molded product such as a film, if the hindered amine compound (B) bleeds out, the hindered amine compound (B) adheres to the mold of the molding machine, which may cause poor appearance of the molded product surface. Therefore, from the viewpoint of suppressing poor appearance, the molecular weight of the hindered amine compound (B) is preferably 1000 or more. The molecular weight of the hindered amine compound (B) is more preferably 1400 or more, further preferably 1700 or more, and particularly preferably 1900 or more. The molecular weight of the hindered amine compound (B) may be 5000 or less.

[0026] The content of the hindered amine compound (B) in the resin composition of the present invention is 0.2 to 5 parts by mass relative to 100 parts by mass of EVOH (A). The content of the hindered amine compound (B) is preferably 0.25 parts by mass or more, more preferably 0.3 parts by mass or more. If the content of the hindered amine compound (B) is less than 0.2 parts by mass, sufficient weather resistance cannot be obtained. On the other hand, if the content of the hindered amine compound (B) is more than 5 parts by mass, the film will be significantly colored after the weather resistance test. In addition, if the content is more than 5 parts by mass, the viscosity of the resin will decrease and stable production may not be possible. The content of the hindered amine compound (B) is preferably 4 parts by mass or less, more preferably 2.5 parts by mass or less, and even more preferably 2 parts by mass or less.

[0027] [Benzotriazole compounds (C)] The resin composition of the present invention contains 0.1 to 5 parts by mass of the benzotriazole compound (C) relative to 100 parts by mass of the EVOH (A). By containing the benzotriazole compound (C) in the resin composition of the present invention, the increase in light transmittance (300 nm) after a weather resistance test tends to be suppressed, and by using it in combination with the hindered amine compound (B), the weather resistance becomes significantly better. The benzotriazole compound is not particularly limited as long as it has a benzotriazole skeleton, and a known compound can be used. From the viewpoint of further improving the weather resistance, it is preferable that the benzotriazole compound (C) has an aromatic ring to which a hydroxyl group is bonded, and has a structure in which the aromatic ring is bonded to a nitrogen atom constituting the benzotriazole ring. Moreover, it is more preferable that the aromatic ring to which the hydroxyl group is bonded is bonded to the nitrogen at the 2-position of the benzotriazole ring. Furthermore, it is preferable that the aromatic ring to which the hydroxyl group is bonded has two or more substituents other than the hydroxyl group and the benzotriazole ring. Moreover, it is preferable that the benzotriazole compound (C) has a halogen group on the benzotriazole ring.

[0028] As the benzotriazole-based compound (C), commercially available products can be used, such as ADK STAB (registered trademark) LA-36 (manufactured by ADEKA CORPORATION, chemical formula: 2-(5-chloro-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol), molecular weight: 315), Tinuvin (registered trademark) 329 (manufactured by BASF Japan Ltd., chemical formula: 2Phenol, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl), molecular weight: 323), Tinuvin (registered trademark) 234 (manufactured by BASF Japan Ltd., chemical formula: Phenol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl), molecular weight: 448), Tinuvin (registered trademark) P (manufactured by BASF Japan Ltd., chemical formula: Phenol, 2-(2H-benzotriazol-2-yl)-4-methyl, molecular weight: 225), Tinuvin (registered trademark) 360 (manufactured by BASF Japan Ltd., chemical formula: Phenol, 2,2'-methylene-bis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)), molecular weight: 659), and the like are included, and Adeka STAB (registered trademark) LA-36 is particularly preferred.

[0029] The content of the benzotriazole compound (C) in the resin composition of the present invention is 0.1 to 5 parts by mass relative to 100 parts by mass of EVOH (A). The content of the benzotriazole compound (C) is preferably 0.2 parts by mass or more, more preferably 0.25 parts by mass or more. When the content of the benzotriazole compound (C) is less than 0.1 parts by mass, the impact strength decreases due to an increase in light transmittance after a weather resistance test and a decrease in molecular weight retention rate. On the other hand, when the content of the benzotriazole compound (C) is more than 5 parts by mass, the film is significantly colored after a weather resistance test. The content of the benzotriazole compound (C) is preferably 3 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1 part by mass or less.

[0030] The benzotriazole-based compound (C) may be used alone or in combination of two or more kinds.

[0031] [Resin composition] In the resin composition of the present invention, the mass ratio (C) / (B) of the benzotriazole compound (C) to the hindered amine compound (B) is preferably 0.2 to 3.5. When the mass ratio (C) / (B) is 0.2 or more, the coloring of the film after the weather resistance test tends to be more suppressed. The mass ratio (C) / (B) is more preferably 0.3 or more, and even more preferably 0.4 or more. When the mass ratio (C) / (B) is 3.5 or less, the coloring of the film tends to be more suppressed. The mass ratio (C) / (B) is more preferably 3.0 or less, even more preferably 2.0 or less, even more preferably 1.5 or less, and particularly preferably 1.0 or less.

[0032] The resin composition of the present invention may contain other optional components other than EVOH (A), hindered amine compound (B) and benzotriazole compound (C), such as boron compounds, carboxylic acids, phosphorus compounds, metal ions, antioxidants, ultraviolet absorbers, plasticizers, antistatic agents, lubricants, colorants, fillers, heat stabilizers, and other resins other than EVOH (A). The resin composition of the present invention may contain two or more of these components. When the resin composition of the present invention contains other optional components, the upper limit of the total content is preferably 1 mass%, and in some cases, 0.5 mass%.

[0033] The resin composition of the present invention preferably contains a boron compound as another component. This can suppress torque fluctuation during heating and melting. The boron compound is not particularly limited, and examples thereof include boric acids, boric acid esters, borate salts, boron hydrides, and the like. Specifically, examples of the boric acids include orthoboric acid, metaboric acid, tetraboric acid, and the like, examples of the borate esters include triethyl borate, trimethyl borate, and the like, and examples of the borates include alkali metal salts, alkaline earth metal salts, borax, and the like of the above-mentioned various boric acids. Among these compounds, orthoboric acid (hereinafter, sometimes simply referred to as boric acid) is preferred. The content of the boron compound is preferably 50 to 400 ppm or less in terms of boron element. If the content of the boron compound is 50 ppm or more, the melt moldability tends to be stable, and is more preferably 70 ppm or more, and even more preferably 100 ppm or more. On the other hand, if the content of the boron compound is 400 ppm or less, there is a tendency that deterioration of moldability can be suppressed, and it is more preferably 350 ppm or less, and may be 300 ppm or less.

[0034] The carboxylic acid prevents the resin composition and thus the molded body from being colored, and suppresses gelation during melt molding. Examples of the carboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, lactic acid, and salts thereof. The carboxylic acid is preferably a carboxylic acid having 4 or less carbon atoms or a saturated carboxylic acid, and more preferably an acetic acid. The acetic acid includes acetic acid and an acetate salt. As the acetic acid, it is preferable to use acetic acid and an acetate salt in combination, and it is more preferable to use acetic acid and sodium acetate in combination. When the resin composition of the present invention includes a carboxylic acid, the lower limit of the content of the carboxylic acid is preferably 50 ppm, more preferably 80 ppm, and even more preferably 120 ppm. In addition, the upper limit of the content of the carboxylic acid is preferably 1,000 ppm, more preferably 500 ppm, and even more preferably 400 ppm. By setting the content of the carboxylic acid to be equal to or more than the above lower limit, a sufficient coloring suppression effect can be obtained, and the occurrence of yellowing can be sufficiently suppressed. On the other hand, by setting the content of carboxylic acids to the above upper limit or less, gelation is less likely to occur during melt molding, particularly during long-term melt molding, and the appearance of the molded product and the like is improved.

[0035] The phosphorus compound suppresses the occurrence of defects such as streaks and fish eyes, and coloring, and improves long-run properties. Examples of the phosphorus compound include phosphates such as phosphoric acid and phosphorous acid. The phosphate may be in the form of primary phosphate, secondary phosphate, or tertiary phosphate. The cationic species of the phosphate is not particularly limited, but is preferably an alkali metal salt or an alkaline earth metal salt, and among these, compounds containing phosphate ions such as sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, and dipotassium hydrogen phosphate are more preferred, and sodium dihydrogen phosphate and dipotassium hydrogen phosphate are even more preferred. When the resin composition of the present invention contains a compound containing phosphate ions as a phosphorus compound, the lower limit of the content of the phosphate ions is preferably 5 ppm, more preferably 10 ppm, even more preferably 20 ppm, and particularly preferably 30 ppm. The upper limit of the content of the phosphorus compound relative to EVOH (A) is preferably 200 ppm, more preferably 150 ppm, and even more preferably 100 ppm. By setting the content of the phosphorus compound to be equal to or more than the above lower limit or equal to or less than the above upper limit, the thermal stability is improved, and the generation of gel-like particles, coloration, etc. during long-term melt molding is less likely to occur.

[0036] Examples of the metal ion include monovalent metal ions, divalent metal ions, and other transition metal ions, and these may be composed of one or more kinds. Among them, monovalent metal ions and divalent metal ions are preferred. As the monovalent metal ion, an alkali metal ion is preferred, for example, an ion of lithium, sodium, potassium, rubidium, and cesium, and from the viewpoint of industrial availability, an ion of sodium or potassium is preferred. In addition, examples of the alkali metal salt that gives the alkali metal ion include an aliphatic carboxylate, an aromatic carboxylate, a carbonate, a hydrochloride, a nitrate, a sulfate, a phosphate, and a metal complex. Among them, an aliphatic carboxylate and a phosphate are preferred from the viewpoint of availability, and specifically, sodium acetate, potassium acetate, sodium phosphate, and potassium phosphate are preferred. In some cases, it is preferred to include a divalent metal ion as the metal ion. When the metal ion includes a divalent metal ion, for example, thermal deterioration of EVOH when trim is recovered and reused may be suppressed, and the occurrence of gels and bumps in the obtained molded body may be suppressed. Examples of divalent metal ions include beryllium, magnesium, calcium, strontium, barium, and zinc ions, and magnesium, calcium, or zinc ions are preferred from the viewpoint of industrial availability. Examples of divalent metal salts that provide divalent metal ions include carboxylates, carbonates, hydrochlorides, nitrates, sulfates, phosphates, and metal complexes, and carboxylates are preferred. Examples of carboxylic acids that constitute carboxylates include carboxylic acids having 1 to 30 carbon atoms, and specifically include acetic acid, propionic acid, butyric acid, stearic acid, lauric acid, montanic acid, behenic acid, octanoic acid, sebacic acid, ricinoleic acid, myristic acid, palmitic acid, and the like, and among these, acetic acid and stearic acid are preferred. When the resin composition of the present invention contains an alkali metal ion, the lower limit of the content of the alkali metal ion is preferably 10 ppm, more preferably 100 ppm, and even more preferably 150 ppm. On the other hand, the upper limit of the content of the alkali metal ion is preferably 400 ppm, and more preferably 350 ppm. When the content of alkali metal ions is at least the above lower limit, the interlayer adhesion of the resulting multilayer structure tends to be good.On the other hand, when the content of metal ions is equal to or less than the upper limit, the coloring resistance tends to be good.

[0037] Examples of the antioxidant include 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, 4,4'-thiobis(6-t-butylphenol), 2,2'-methylene-bis(4-methyl-6-t-butylphenol), octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, etc. Examples of the ultraviolet absorber include ethylene-2-cyano-3,3'-diphenylacrylate, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-oxybenzophenone, etc.

[0038] Examples of the plasticizer include dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, phosphate ester, etc. Examples of the antistatic agent include pentaerythritol monostearate, sorbitan monopalmitate, sulfated polyolefins, polyethylene oxide, polyethylene glycol (trade name: Carbowax), etc.

[0039] Examples of the lubricant include ethylene bisstearamide and butyl stearate. Examples of the colorant include carbon black, phthalocyanine, quinacridone, indoline, azo pigments, and red iron oxide. Examples of the filler include glass fiber, wollastonite, calcium silicate, talc, and montmorillonite. Examples of the heat stabilizer include hindered phenol compounds and hindered amine compounds.

[0040] Examples of the resin other than EVOH (A) include polyamide and polyolefin.

[0041] In the resin composition of the present invention, the proportion of EVOH (A), hindered amine compound (B) and benzotriazole compound (C) is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and particularly preferably 99% by mass or more. The resin composition of the present invention may be substantially composed of only EVOH (A), hindered amine compound (B) and benzotriazole compound (C), and the resin composition of the present invention may be composed of only EVOH (A), hindered amine compound (B) and benzotriazole compound (C). In this specification, "consists essentially of" means that optional components can be contained within a range that does not affect the effects of the present invention, and "consists only of" means that optional components other than impurities that are inevitably contained are excluded.

[0042] The resin composition of the present invention is applied to a film having a thickness of 100 μm, which is formed from the resin composition of the present invention, at 63° C., 50% RH, and an irradiation intensity of 1000 W / m 2 It is preferable that the weight average molecular weight (Mw) retention rate after a weather resistance test in which the composition is irradiated with light at 300° C. for 50 hours is 90% or more. Here, the weight average molecular weight (Mw) retention rate means the retention rate (%) calculated by dividing the Mw after the weather resistance test by the Mw before the weather resistance test (Mw before the weather resistance test / Mw before the weather resistance test×100). The weight average molecular weight (Mw) retention rate is more preferably 93% or more, and even more preferably 95% or more. In addition, the weight average molecular weight (Mw) retention rate after the weather resistance test may be 99.9% or less. When the Mw retention rate is within the above range, the impact strength after the weather resistance test tends to be good. The weather resistance test and the Mw retention rate can be measured by the method described in the examples.

[0043] The resin composition of the present invention is applied to a film having a thickness of 100 μm, which is formed from the resin composition of the present invention, at 63° C., 50% RH, and an irradiation intensity of 1000 W / m 2It is preferable that the number average molecular weight (Mn) retention rate after a weather resistance test in which the composition is irradiated with light at 300° C. for 50 hours is 80% or more. Here, the number average molecular weight (Mn) retention rate means the retention rate (%) calculated by dividing Mn after the weather resistance test by Mn before the weather resistance test (Mn before the weather resistance test / Mn before the weather resistance test×100). The number average molecular weight (Mn) retention rate is more preferably 85% or more, and even more preferably 87% or more. In addition, the number average molecular weight (Mn) retention rate after the weather resistance test may be 99.9% or less. When the Mn retention rate is within the above range, the impact strength after the weather resistance test tends to be good. The weather resistance test and the Mn retention rate can be measured by the method described in the examples.

[0044] When the molecular weight retention rates of Mw and Mn are within the above ranges, the mechanical properties such as the impact strength of the laminate are maintained at a high level.

[0045] The resin composition of the present invention preferably has a light transmittance (300 nm) of 50% or less, as measured in accordance with JIS K 7361-1:1997 for a 100 μm thick film made of the resin composition of the present invention, from the viewpoint of improving the weather resistance of the entire roll when the laminate roll is stored outdoors. The light transmittance (300 nm) is more preferably 30% or less, even more preferably 10% or less, and particularly preferably 5% or less. In addition, when the film is stored at 63° C. and 50% RH, the irradiation intensity is 1000 W / m 2 The light transmittance (300 nm) after a weather resistance test in which the film is irradiated with light at 63° C. for 50 hours is preferably 50% or less, more preferably 30% or less, even more preferably 10% or less, and particularly preferably 8% or less. 2 The difference in light transmittance before and after a weather resistance test in which the film is irradiated with light at 30° C. for 50 hours (transmittance (%) after weather resistance test) - (transmittance (%) before weather resistance test) is preferably 4.0% or less, more preferably 3.0% or less, even more preferably 2.3% or less, and particularly preferably 2.0% or less.

[0046] The resin composition of the present invention has an impact strength of preferably 17.5 kgf cm or more, more preferably 19.0 kgf cm or more, and even more preferably 19.8 kgf cm or more, of a 100 μm thick film made of the resin composition of the present invention. The impact strength may be 25.0 kgf cm or less. The impact strength may also be 25.0 kgf cm or less. 2 The impact strength after a weather resistance test in which the material is irradiated with light at 35° C. for 50 hours is preferably 17.5 kgf cm or more, more preferably 18.0 kgf cm or more, even more preferably 18.5 kgf cm or more, and particularly preferably 19.5 kgf cm or more. The impact strength can be measured by the method described in the Examples.

[0047] The method for producing the resin composition of the present invention is not particularly limited, and for example, the resin composition can be produced by mixing and melt-kneading EVOH (A), a hindered amine compound (B), a benzotriazole compound (C), and various additives such as the above-mentioned other components as necessary. Specifically, the melt-kneading can be carried out using a known mixing or kneading device such as a kneader-ruder, an extruder, a mixing roll, or a Banbury mixer. The temperature during melt-kneading is usually 110 to 300°C. Various additives such as the above-mentioned other components may be contained in EVOH (A) in advance. The method for pre-containing the additives in EVOH (A) is not particularly limited, and for example, various additives can be pre-containing EVOH (A) by immersing EVOH (A) pellets in a solution containing various additives and drying them.

[0048] The resin composition of the present invention can also be produced by a production method including a step of going through a masterbatch. As the production method including a step of going through a masterbatch, a production method including a step of melt-kneading 100 parts by mass of EVOH (A), 2 to 20 parts by mass of a hindered amine compound (B), and 1 to 15 parts by mass of a benzotriazole compound (C) to obtain a masterbatch in advance, and a step of melt-kneading the obtained masterbatch with EVOH (A) is preferable. By providing a step of obtaining a masterbatch in advance, the hindered amine compound (B) and the benzotriazole compound (C) tend to be better dispersed in EVOH (A) than other mixing methods, and the weather resistance tends to be more excellent. The EVOH (A) contained in the masterbatch and the EVOH (A) used when further melt-kneading the masterbatch may be the same or different. The production method of the resin composition of the present invention preferably includes a step of going through a masterbatch from the viewpoint of further improving the weather resistance of the obtained resin composition.

[0049] [Master batch] A masterbatch used in a method for producing a resin composition including a process of the above-mentioned masterbatch is also an embodiment of the present invention. The masterbatch of the present invention contains EVOH (A), a hindered amine compound (B) and a benzotriazole compound (C) at high concentrations, and is used by diluting with EVOH (A) at a specified ratio when producing the resin composition of the present invention. The masterbatch of the present invention contains EVOH (A), a hindered amine compound (B) and a benzotriazole compound (C), and contains 2 to 20 parts by mass of the hindered amine compound (B) and 1 to 15 parts by mass of the benzotriazole compound (C) per 100 parts by mass of EVOH (A). When the contents of the hindered amine compound (B) and the benzotriazole compound (C) are within the above-mentioned ranges, the masterbatch can be stably produced.

[0050] The method of adding the hindered amine compound (B) and the benzotriazole compound (C) to the master batch of the present invention is not particularly limited, and examples thereof include a method of dry-blending EVOH (A), the hindered amine compound (B) and the benzotriazole compound (C) and further melt-kneading them in an extruder, a method of immersing EVOH (A) in a solution in which the hindered amine compound (B) and the benzotriazole compound (C) are dissolved, a method of melting EVOH (A) and mixing the hindered amine compound (B) and the benzotriazole compound (C), and a method of melt-blending EVOH (A), the hindered amine compound (B) and the benzotriazole compound (C) in an extruder, etc. Among them, a method of dry-blending EVOH (A), the hindered amine compound (B) and the benzotriazole compound (C) and further melt-kneading them in an extruder is preferred.

[0051] [Laminate] The laminate of the present invention has at least one layer made of the resin composition of the present invention and has layers made of other components. The laminate has advantages such as improved functionality compared to a molded body having a single layer structure. The lower limit of the number of layers of the laminate may be 2 layers or 3 layers. The upper limit of the number of layers of the laminate may be 1000 layers, 100 layers, or 10 layers. The laminate of the present invention may further have a layer formed from a component other than a resin, such as a layer formed from paper, a metal layer, etc.

[0052] Examples of layers made of other components include a thermoplastic resin layer formed from a thermoplastic resin and an adhesive resin layer formed from an adhesive resin. The layer structure of the laminate of the present invention is not particularly limited, and examples of structures include a layer made of the resin composition of the present invention, E, a layer obtained from an adhesive resin, and a layer obtained from a thermoplastic resin, and structures such as T / E / T, E / Ad / T, T / Ad / E / Ad / T, E / Ad / T / Ad / E, and E / Ad / T / Ad / E / Ad / T / Ad / E / Ad / E, when the layer is directly laminated with " / ". Each of these layers may be a single layer or multiple layers. In addition, other layers other than those described above may be included within a range that does not impair the effects of the present invention. Examples of other layers include a recovery layer. In particular, the recovery composition containing the recovered material of the laminate of the present invention may be reused as part or all of the recovery layer.

[0053] Examples of the thermoplastic resin 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 copolymers; polyesters such as polyethylene terephthalate; polyester elastomers; polyamides such as nylon-6 and nylon-66; polystyrene; polyvinyl chloride, polyvinylidene chloride, acrylic resins, vinyl ester resins, polyurethane elastomers, polycarbonate, chlorinated polyethylene, chlorinated polypropylene, etc. Among these, polypropylene, polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyamide, polystyrene, and polyester are preferably used, polypropylene and polyethylene are more preferred, and polyethylene is even more preferred.

[0054] The adhesive resin is not particularly limited as long as it has adhesiveness to the gas barrier layer and layers composed of other components, but an adhesive resin containing a carboxylic acid-modified polyolefin is preferred. As the carboxylic acid-modified polyolefin, a modified olefin polymer containing a carboxyl group in which an ethylenically unsaturated carboxylic acid, its ester, or its anhydride is chemically bonded to an olefin polymer is preferred, and a maleic anhydride-modified olefin polymer is more preferred. Here, the olefin polymer refers to 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 preferred, and linear low-density polyethylene and ethylene-vinyl acetate copolymer are particularly preferred.

[0055] The method for producing the laminate of the present invention is not particularly limited, and examples thereof include a method of melt-extruding other components onto a molded article (film, sheet, etc.) made of the resin composition of the present invention, a method of co-extruding the resin composition of the present invention and other components, a method of coinjection molding the resin composition of the present invention and other components, and a method of laminating a barrier layer made of the resin composition of the present invention and a layer made of other components using a known adhesive such as an organic titanium compound, an isocyanate compound, or a polyester-based compound.

[0056] The method for co-extrusion of the resin composition of the present invention and other components is not particularly limited, and examples thereof include a multi-manifold merging type T-die method, a feed block merging type T-die method, and an inflation method.

[0057] [Application] The resin composition of the present invention has very good weather resistance and excellent manufacturing stability, and is suitable for use as an industrial film or pipe having a gas barrier layer made of such a resin composition. More specifically, it is suitable for agricultural films such as soil fumigation films, silage films, and greenhouse films; grain storage bags; geomembranes; hot water circulation pipes, fuel pipes, and the like. The present invention also provides agricultural films (preferably soil fumigation films, silage films, or greenhouse films), grain storage bags, geomembranes, and pipes (preferably hot water circulation pipes or fuel pipes) having a gas barrier layer made of such a resin composition of the present invention.

[0058] The resin composition of the present invention is particularly useful when used as a soil fumigation film used to prevent the evaporation of chloropicrin, methyl bromide, and the like, which are used as soil fumigants, and as a silage film for wrapping silage that is acidic due to fermentation. Under these conditions, the resin composition of the present invention is exposed to acidic conditions by the chemicals or silage. When used outdoors for a long period of time under acidic conditions, the deterioration of the film is accelerated, but even under such conditions, the soil fumigation film and silage film made of the resin composition of the present invention have very good weather resistance. EXAMPLES

[0059] The present invention will be further described below with reference to examples, but the present invention is not limited to these. The measurement, calculation and evaluation methods were as follows.

[0060] [Materials used] <Hindered amine compound (B)> B-1: Tinuvin NOR 371 (BASF Japan Ltd., molecular weight 1000 or more) B-2: FLAMESTAB NOR 116 (BASF Japan Ltd., molecular weight 1000 or more) B-3: HOSTAVIN NOW (manufactured by Clariant, molecular weight 1000 or more) <Benzotriazole Compounds (C)> C-1: Adeka STAB LA-36 (ADEKA Corporation, 2-(5-chloro-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol) C-2: Tinuvin 329 (BASF Japan Ltd., 2Phenol, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)) C-3: Tinuvin 234 (BASF Japan Ltd., Phenol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)) <Additive (C') used in Comparative Examples> C'-1: Irganox 1098 (BASF Japan Ltd., N,N'-(1,6-Hexanediyl)bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide]) C'-2: Chimassorb 81 (BASF Japan Ltd., Methanone, 2-hydroxy-4-(octyloxy)-phenyl)

[0061] [Evaluation method] (1) Measurement of phosphate ion, alkali metal ion, and boron element content 0.5g of the resin composition pellets obtained in the examples and comparative examples were placed in a Teflon (registered trademark) pressure vessel, and 5mL of concentrated nitric acid was added thereto and decomposed at room temperature for 30 minutes. After 30 minutes, the vessel was closed and decomposed by heating at 150°C for 10 minutes and then at 180°C for 5 minutes using a wet decomposition device (Actac Corporation: "speedwave4"), and then cooled to room temperature. This treatment liquid was transferred to a 50mL measuring flask (TPX) and made up to 10mL with pure water. The metal content of this solution was analyzed using an ICP emission spectrometer (PerkinElmer's "Avio500") to measure the content of phosphate ions, sodium metal ions, and boron elements.

[0062] (2) Determination of acetic acid 20 g of the resin composition pellets obtained in the Examples and Comparative Examples were added to 100 ml of ion-exchanged water and extracted by heating at 95° C. for 6 hours. The extract was neutralized and titrated with 1 / 50 N NaOH using phenolphthalein as an indicator to quantify the acetic acid content.

[0063] (3) Weather resistance test Examples and Comparative Examples The obtained single-layer film was subjected to UV-ray irradiation at a radiation intensity of 1000 W / m using an Eye Super UV Tester "SUV-W15" manufactured by Iwasaki Electric Co., Ltd. 2 An accelerated weather resistance test was conducted for 50 hours under conditions of a black panel temperature of 63°C and a relative humidity of 50%, and the following parameters (4) molecular weight retention, (5) light transmittance, (6) impact strength, and (7) film coloration were evaluated before and after the test.

[0064] (4) Molecular weight maintenance rate The weight average molecular weight (Mw) and number average molecular weight (Mn) of the monolayer film before and after the weather resistance test were measured by gel permeation chromatography (GPC) under the following measurement conditions: Apparatus: Tosoh Corporation gel permeation chromatography "HLC-8320" Column: 2 "GMHHR-H(S)" columns manufactured by Tosoh Corporation Column temperature: 40℃ Mobile phase: Hexafluoroisopropanol + 20 mM CF 3 COONa, flow rate: 0.2mL / min Detector: RI, Sample concentration: 0.1% by weight (hexafluoroisopropanol solution) Based on the measurement results, the difference in Mw before and after the weather resistance test ((Mw before weather resistance test) - (Mw after weather resistance test)) was divided by the Mw before the weather resistance test to calculate the Mw retention rate (%) (((Mw before weather resistance test) - (Mw after weather resistance test)) / (Mw before weather resistance test) x 100). Similarly, the difference in Mn before and after the weather resistance test ((Mn before weather resistance test) - (Mn after weather resistance test)) was divided by the Mn before the weather resistance test to calculate the Mn retention rate (%) (((Mn before weather resistance test) - (Mn after weather resistance test)) / (Mn before weather resistance test) x 100).

[0065] (5)Light transmittance The light transmittance at a wavelength of 300 nm of the monolayer films obtained in the examples and comparative examples was measured using a UV-2450 ultraviolet-visible spectrophotometer manufactured by Shimadzu Corporation. In addition, the difference in light transmittance before and after the weather resistance test of the above evaluation method (2) was calculated.

[0066] (6) Impact strength The monolayer films obtained in the examples and comparative examples were conditioned at 23°C and 50% RH for 24 hours, and then the impact strength was measured using a film impact tester under the same conditions. The measurement was carried out five times at different locations, and the average value was used as the measurement result.

[0067] (7) Coloring The monolayer films obtained in the Examples and Comparative Examples were visually observed and the degree of yellowing was evaluated according to the following criteria, of which A, B, and C were determined to be usable levels. A: No yellowing was observed at all. B: Slight yellowing was observed. C: Slight yellowing was observed. D: Yellowing was observed. E: Significant yellowing was observed.

[0068] Example 1 A hydrous EVOH pellet having an ethylene unit content of 38 mol% and a saponification degree of 99.9 mol% was immersed in an aqueous solution containing acetic acid, phosphoric acid, sodium acetate, and boric acid at 25°C for 6 hours while stirring, then deliquored, dried at 80°C for 4 hours in a hot air dryer ("DN6101" manufactured by Yamato Scientific Co., Ltd.), and then dried at 120°C for 40 hours to obtain a dried EVOH pellet (EVOH-1, moisture content 0.25%, MFR (190°C, under a load of 2160g) 1.7g / 10min). The concentrations of acetic acid, phosphoric acid, sodium acetate, and boric acid were appropriately adjusted so that the contents in the resin composition obtained in this example were 100 ppm for acetic acid, 40 ppm for phosphate ion, 150 ppm for sodium ion, and 180 ppm for boron element.

[0069] 100 parts by mass of the obtained dried EVOH pellets were dry-blended with 0.4 parts by mass of Tinuvin NOR 371 (B-1) (manufactured by BASF Japan Ltd.) and 0.3 parts by mass of Adeka STAB LA-36 (C-1) (manufactured by ADEKA Corporation), and melt-kneaded under the following conditions using a 25 mm extruder "2D30W2" manufactured by Toyo Seiki Seisakusho Co., Ltd., and pelletized to obtain resin composition pellets. The obtained resin composition pellets were measured for the phosphate ion, alkali metal ion, and boron element contents by the method described in the above evaluation method (1), and the phosphate ion content was 40 ppm, the sodium ion content was 150 ppm, and the boron element content was 180 ppm. Set temperature C1 / C2 / C3 / C4 / C5 / die = 180 / 210 / 210 / 210 / 210 / 210℃ Screw rotation speed: 100 rpm Discharge amount: 6.0kg / hour

[0070] Using the obtained resin composition pellets, a monolayer film was formed under the following conditions using a 20 mm single screw extruder "D2020" (D (mm) = 20, L / D = 20, compression ratio = 3.5, screw: full flight) manufactured by Toyo Seiki Seisakusho Co., Ltd. The obtained monolayer film was evaluated for molecular weight retention, light transmittance, impact strength and coloration before and after the weather resistance test using the methods described in the above evaluation methods (2) to (6). The results are shown in Table 1. Setting temperature: C1 / C2 / C3 / die = 180 / 210 / 210 / 210℃ Screw rotation speed: 100 rpm Discharge amount: 3.0kg / hour Take-off roll temperature: 80℃ Take-off roll speed: 1.5m / min Film thickness: 100μm

[0071] Examples 2 to 12, Comparative Examples 1 to 10 Resin composition pellets and a single layer film were prepared and evaluated in the same manner as in Example 1, except that the type of EVOH (A), the type and content of the hindered amine compound (B), the type and content of the benzotriazole compound, and the content of the boron compound were changed as shown in Table 1. The results are shown in Table 1.

[0072] The monolayer films obtained in Example 1 and Comparative Example 1 were subjected to a weather resistance test according to the method described in the above evaluation method (3), and then the oxygen permeability was measured in accordance with JIS K 7126:2006 (isobaric method). The monolayer film obtained in Example 1 had a lower (superior) oxygen permeability after the weather resistance test than the monolayer film obtained in Comparative Example 1. Since Example 1 contains a specific amount of the hindered amine compound (B) and the benzotriazole compound (C), it is presumed that it has a superior weather resistance compared to Comparative Example 1, which does not contain the hindered amine compound (B) and the benzotriazole compound (C), and was able to maintain a sufficient oxygen permeability even after the weather resistance test.

[0073] Example 13 In Example 1, except that the hydrous EVOH pellets had an ethylene unit content of 44 mol% and a saponification degree of 99.9 mol% as the hydrous EVOH pellets, dried EVOH pellets (EVOH-2) were obtained, and resin composition pellets and a monolayer film were produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0074] Example 14 93.5 parts by mass of the dried EVOH pellets obtained in Example 1 were dry-blended with 3.7 parts by mass of Tinuvin NOR 371 (B-1, manufactured by BASF Japan Ltd.) and 2.8 parts by mass of Adeka STAB LA-36 (C-1, manufactured by ADEKA Corporation). The mixture was melt-kneaded under the following conditions using a 25 mm extruder "2D30W2" manufactured by Toyo Seiki Seisakusho Co., Ltd., and then pelletized to obtain master batch pellets. Setting temperature: C1 / C2 / C3 / C4 / C5 / die = 180 / 210 / 210 / 210 / 210 / 210℃ Screw rotation speed: 100 rpm Discharge amount: 6.0kg / hour

[0075] Furthermore, 90 parts by mass of the dried EVOH pellets obtained in Example 1 and 10 parts by mass of the master batch pellets were dry blended, and then a single layer film was formed and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0076] The dry EVOH obtained in Example 1 and the master batch pellets obtained above were measured for the contents of phosphate ion, alkali metal ion, boron element, and acetic acid by the methods described in the evaluation methods (1) and (2) above. The contents in the dry EVOH pellets and the master batch pellets were 40 ppm for phosphate ion, 150 ppm for sodium ion, 180 ppm for boron, and 100 ppm for acetic acid. From the above results, it was determined that the dry blend product also contained the same amounts of phosphate ion, sodium ion, boron element, and acetic acid as above.

[0077] [Table 1]

[0078] Example 15 Using the resin composition pellets of Example 1 as the intermediate layer, polyethylene "Novatec (trademark) PE LF128" (PE) manufactured by Japan Polyethylene Co., Ltd. as the thermoplastic resin layer, and adhesive polyolefin "Admer (trademark) NF518" (Ad) manufactured by Mitsui Chemicals, Inc. as the adhesive layer, a 3-kind 5-layer laminate (PE / Ad / resin composition layer / Ad / PE=40 μm / 10 μm / 20 μm / 10 μm / 40 μm) was obtained under the following conditions. The film-forming equipment had a temperature-controllable take-up roll after the extruder having a film-forming die, and the obtained multilayer structure was wound up by a winding machine. <Film forming conditions> Extruder for resin composition pellets: Single-screw extruder (lab machine ME type CO-EXT, manufactured by Toyo Seiki Co., Ltd.) Caliber 20mmφ, L / D=20, Screw full flight type Feeding section / compression section / metering section / die=180 / 210 / 210 / 210℃ PE extruder: Single screw extruder (GT-32-A, manufactured by Plastics Engineering Research Institute Co., Ltd.) Caliber 32mmφ, L / D=28, Screw full flight type Feeding section / compression section / metering section / die=180 / 220 / 220 / 220℃ Ad extruder: Single screw extruder (SZW20GT-20MG-STD, Technovel Co., Ltd.) Caliber 20mmφ, L / D=20, Screw full flight type Feeding section / compression section / metering section / die=180 / 220 / 220 / 220℃ Die: 300mm wide coat hanger die (manufactured by Plastics Engineering Research Institute) Take-off roll temperature: 60℃

[0079] The resulting multi-layer structure had excellent weather resistance and performed without any problems even when stored outdoors for a long period of time.

Claims

1. An ethylene-vinyl alcohol copolymer (A) having an ethylene unit content of 20 to 60 mol%, A hindered amine compound (B) having a 2,2,6,6-tetraalkylpiperidine ring structure and having an alkoxy group bonded to a nitrogen atom in the structure, And a benzotriazole compound (C) are contained, A resin composition containing 0.2 to 5 parts by mass of the hindered amine compound (B) and 0.1 to 5 parts by mass of the benzotriazole compound (C) with respect to 100 parts by mass of the ethylene-vinyl alcohol copolymer (A).

2. The resin composition according to claim 1, wherein the mass ratio (C) / (B) of the benzotriazole compound (C) to the hindered amine compound (B) is 0.2 to 3.

5.

3. The resin composition according to claim 1, wherein the molecular weight of the hindered amine compound (B) is 1000 or more.

4. The resin composition according to claim 1, wherein the benzotriazole compound (C) has an aromatic ring to which a hydroxyl group is bonded, and the aromatic ring is bonded to a nitrogen atom constituting the benzotriazole ring.

5. The resin composition according to claim 4, wherein the aromatic ring to which the hydroxyl group is bonded has two or more substituents other than the benzotriazole ring and the hydroxyl group.

6. The resin composition according to claim 1, wherein the benzotriazole compound (C) has a halogen group on the benzotriazole ring.

7. The resin composition according to claim 1, further containing 5 ppm or more and 200 ppm or less of phosphate ions and 10 ppm or more and 400 ppm or less of alkali metal ions.

8. The resin composition according to claim 1, further containing 50 to 400 ppm of a boron compound in terms of boron element.

9. Regarding a film having a thickness of 100 μm made of the resin composition according to claim 1, the light transmittance at a wavelength of 300 nm measured in accordance with JIS K 7361-1:1997 is 50% or less. The resin composition according to claim 1.

10. Regarding the film with a thickness of 100 μm made of the resin composition according to claim 1, in terms of the light transmittance at a wavelength of 300 nm measured in accordance with JIS K 7361-1:1997, under 63 °C and 50% RH, the irradiation intensity is 1000 W / m ２ The resin composition according to claim 1, wherein the difference in light transmittance before and after the weather resistance test of irradiating with light at 50 hours is (transmittance after the weather resistance test (%)) - (transmittance before the weather resistance test (%)) and is 4.0% or less.

11. A laminate including a layer made of the resin composition according to any one of claims 1 to 10.

12. An industrial film including the laminate according to claim 11.

13. A pipe including the laminate according to claim 11.

14. A masterbatch for producing the resin composition according to any one of claims 1 to 10, An ethylene-vinyl alcohol copolymer (A) having an ethylene unit content of 20 to 60 mol%, a hindered amine compound (B) having a 2,2,6,6-tetraalkylpiperidine ring structure and having an alkoxy group bonded to a nitrogen atom in the structure, and a benzotriazole compound (C), A masterbatch containing 2 to 20 parts by mass of the hindered amine compound (B) and 1 to 15 parts by mass of the benzotriazole compound (C) with respect to 100 parts by mass of the ethylene-vinyl alcohol copolymer (A).

15. A step of preliminarily melt-kneading 100 parts by mass of an ethylene-vinyl alcohol copolymer (A) having an ethylene unit content of 20 to 60 mol%, 2 to 20 parts by mass of a hindered amine compound (B) having a 2,2,6,6-tetraalkylpiperidine ring structure and having an alkoxy group bonded to a nitrogen atom in the structure, and 1 to 15 parts by mass of a benzotriazole compound (C) to obtain a masterbatch, A step of melt-kneading the obtained masterbatch and an ethylene-vinyl alcohol copolymer (A) to obtain a resin composition containing 0.2 to 5 parts by mass of the hindered amine compound (B) and 0.1 to 5 parts by mass of the benzotriazole compound (C) with respect to 100 parts by mass of the ethylene-vinyl alcohol copolymer (A). A method for producing a resin composition comprising the steps.

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