JP2024002561A - Ethylene-vinyl alcohol copolymer resin composition having weather resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: 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

COPYRIGHT: (C)2024,JPO&INPIT

Description

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

In general, ethylene-vinyl alcohol copolymers (hereinafter sometimes abbreviated as "EVOH") have excellent transparency, gas barrier properties, fragrance retention, solvent resistance, oil resistance, etc. It is used by being formed into films and sheets for food packaging materials, pharmaceutical packaging materials, industrial chemical packaging materials, agricultural chemical packaging materials, containers such as bottles, etc. It is also widely used in industrial films and pipes due to its barrier properties, heat retention properties, and stain resistance. However, in applications such as industrial films and pipes, they are often exposed to UV rays (sunlight) or chemicals such as pesticides for long periods of time, and the physical properties of EVOH (mechanical strength, gas barrier properties, There is a concern that the anti-fog properties, etc.) may decrease. In order to suppress such deterioration of physical properties, for example, Patent Document 1 describes that EVOH is blended with a hindered amine compound and a hindered phenol compound having a specific structure.

International Publication No. 2018/052014

In recent years, there has been a demand for EVOH resin compositions with higher weather resistance, and when using a resin composition in which EVOH is blended with a hindered amine compound and a hindered phenol compound having a specific structure, as in the conventional technology described above, In some cases, the weather resistance was also insufficient. In particular, when used outdoors for a long period of time, it is important to be able to maintain mechanical properties such as impact strength after long-term outdoor use, but with the above conventional technology, maintaining impact strength after long-term outdoor use is insufficient. There were cases where it happened. In addition, when many additives are used to increase weather resistance to maintain impact strength, coloration of the film becomes a problem, and it has been found that it is difficult to maintain both impact strength and suppress film coloration. Ta. Furthermore, for example, when a roll of film is stored outdoors, deterioration of the film inside the roll can be more effectively suppressed by keeping the transmittance of ultraviolet light (for example, 300 nm) low. It has been found that the light transmittance of ultraviolet light increases after being used outdoors for a period of time.

The present invention has been made to solve the above problems, and has developed an EVOH that has weather resistance that can maintain impact strength and light transmittance even after long-term outdoor use, and that can suppress discoloration of the resulting film. The object of the present invention is to provide a resin composition, a laminate, an industrial film, a pipe, a method for producing the resin composition, and a masterbatch used in the production method.

According to the present invention, the above objects are [1] an ethylene-vinyl alcohol copolymer (A) having an ethylene unit content of 20 to 60 mol% (hereinafter sometimes abbreviated as "EVOH (A)"), 2,2 , 6,6-tetraalkylpiperidine ring structure, and a hindered amine compound (B) having an alkoxy group bonded to the nitrogen atom in the structure (hereinafter simply referred to as "hindered amine compound (B)") ), and a benzotriazole compound (C), and 0.2 to 5 parts by mass of the hindered amine compound (B) and the benzotriazole compound (C), based on 100 parts by mass of the EVOH (A). ); a resin composition containing 0.1 to 5 parts by mass;
[2] The resin composition of [1], wherein the mass ratio (C)/(B) of the benzotriazole compound (C) and the hindered amine compound (B) is 0.2 to 3.5;
[3] The resin composition of [1] or [2], wherein the hindered amine compound (B) has a molecular weight of 1000 or more;
[4] The benzotriazole compound (C) has a structure in which a hydroxyl group is bonded to an aromatic ring, and the aromatic ring is bonded to a nitrogen atom constituting the benzotriazole ring, [1] to [3] ] Any resin composition;
[5] The resin composition of [4], wherein the aromatic ring to which the hydroxyl group is bonded has two or more substituents in addition to the benzotriazole ring and the hydroxyl group;
[6] The resin composition according to any one of [1] to [5], which has a halogen group on the benzotriazole ring of the benzotriazole compound (C);
[7] The resin composition according to any one of [1] to [6], further comprising 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 any one of [1] to [7], further containing a boron compound in an amount of 50 to 400 ppm in terms of boron element;
[9] A film with a thickness of 100 μm made of the resin composition according to any one of [1] to [8] has a light transmittance of 50% or less at a wavelength of 300 nm measured in accordance with JIS K 7361-1:1997. The resin composition according to any one of [1] to [8];
[11] For a 100 μm thick film made of the resin composition of any 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, Difference in light transmittance before and after a weather resistance test in which light is irradiated for 50 hours at an irradiation intensity of 1000 W/ ^m2 under 50% RH (transmittance after weather resistance test (%)) - (transmittance before weather resistance test (%) )) is 4.0% or less, the resin composition according to any one of [1] to [9];
[11] A laminate comprising a layer made of the resin composition according to any one of [1] to [8];
[12] An industrial film comprising the laminate of any one of [9] to [11];
[13] A pipe containing the laminate of any one of [9] to [11];
[14] A masterbatch for producing the resin composition according to any one of [1] to [8], comprising EVOH (A), a hindered amine compound (B), and a benzotriazole compound ( C), a masterbatch containing 2 to 20 parts by mass of the EVOH (B) and 1 to 15 parts by mass of the benzotriazole compound (C) based on 100 parts by mass of the EVOH (A);
[15] A step of melt-kneading 100 parts by mass of EVOH (A), 2 to 20 parts by mass of hindered amine compound (B), and 1 to 15 parts by mass of benzotriazole compound (C) to obtain a masterbatch; The obtained masterbatch and EVOH (A) are melt-kneaded, and to 100 parts by mass of the EVOH (A), 0.2 to 5 parts by mass of the hindered amine compound (B) and the benzotriazole compound (C ) A method for producing a resin composition, the method comprising: obtaining a resin composition containing 0.1 to 5 parts by mass
This is achieved by providing.

According to the present invention, there is provided a resin composition, a laminate, and an industrial-use resin composition containing EVOH, which has weather resistance that can maintain impact strength and light transmittance even after long-term outdoor use, and which can suppress discoloration of the obtained film. It is possible to provide a film, a pipe, a method for producing the resin composition, and a masterbatch used in the method.

The resin composition of the present invention is a resin composition containing EVOH (A), a hindered amine compound (B), and a benzotriazole compound (C), wherein the hindered amine compound It contains 0.2 to 5 parts by weight of the compound (B) and 0.1 to 5 parts by weight of the benzotriazole compound (C). When the resin composition of the present invention contains the hindered amine compound (B), it tends to suppress deterioration of the hue of the film after long-term outdoor use, but the light transmittance at 300 nm increases significantly after long-term outdoor use. There is a tendency to In addition, when the benzotriazole compound (C) is included, 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. The hue tends to deteriorate. Furthermore, because the resin composition of the present invention contains specific amounts of the hindered amine compound (B) and the benzotriazole compound (C), surprisingly, the hue of the film after long-term outdoor use does not deteriorate. The increase in light transmittance at 300 nm after long-term outdoor use can be significantly suppressed, and furthermore, the decrease in impact strength after long-term outdoor use can be suppressed. The reason why the decrease in impact strength can be suppressed is not clear, but when specific amounts of hindered amine compounds (B) and benzotriazole compounds (C) are included, the decrease in the molecular weight of EVOH (A) after the weather resistance test is However, when only one of the hindered amine compound (B) or the benzotriazole compound (C) is included, molecular weight reduction cannot be suppressed very much. It is presumed that the synergistic effect of compound (C) suppresses the decrease in molecular weight and suppresses the decrease in impact strength. In addition, the resin composition of the present invention can also suppress the deterioration of barrier properties after long-term outdoor use, so even if it is used for the purpose of suppressing migration of agricultural chemicals, etc., it can maintain its function for a long period of time. . The barrier property can be indirectly evaluated by oxygen permeability measured in accordance with JIS K 7126:2006 (isobaric method).

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

[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 vinyl ester using an alkali catalyst or the like. Typical vinyl esters include 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.

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 deteriorate. On the other hand, if the ethylene unit content exceeds the above 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 determined by ¹ H-NMR measurement.

The lower limit of the degree of saponification of EVOH (A) is preferably 90 mol%, more preferably 95 mol%, and even more preferably 99 mol%. When the degree of saponification of EVOH (A) is at least the above-mentioned lower limit, the gas barrier properties of the resulting laminate and the like are improved. The degree of saponification 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). Moreover, the upper limit of the degree of saponification may be 99.99 mol%. The degree of saponification of EVOH (A) is determined by ¹ H-NMR measurement.

EVOH (A) may contain monomer units other than ethylene, vinyl ester, and vinyl alcohol, as long as they do not impede the effects of the present invention. In particular, by introducing a modifying group containing a primary hydroxyl group having a specific structure, it may be possible to achieve both high levels of 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 not contained. 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-1-hexene, 1, Ester group-containing alkenes such as 3-diacetoxy-2-methylenepropane or saponified products thereof; Unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, or their anhydrides, salts, mono- or dialkyl esters, etc.; acrylonitrile Nitriles such as , methacrylonitrile; amides such as acrylamide and methacrylamide; olefin sulfonic acids or salts thereof such as vinylsulfonic acid, allylsulfonic acid, and methalylsulfonic acid; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(β Vinyl silane compounds such as -methoxy-ethoxy)silane and γ-methacryloxypropylmethoxysilane; examples include alkyl vinyl ethers, vinyl ketones, N-vinylpyrrolidone, vinyl chloride, and vinylidene chloride.

EVOH (A) may be modified by urethanation, acetalization, cyanoethylation, oxyalkylenation, etc., as necessary. Oxyalkylenation can be carried out using epoxy compounds, for example, 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, 1,2-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 epoxycycloalkanes, various epoxycycloalkenes, and the like. Among these, 1,2-epoxybutane, 2,3-epoxybutane, epoxypropane, epoxyethane or glycidol are preferred, and epoxypropane or glycidol is more preferred.

The melt flow rate (MFR) of EVOH (A) (190°C, under a load of 2160 g) is preferably 0.1 to 30 g/10 minutes, more preferably 0.3 g to 25 g/10 minutes, and It is preferably 0.5g to 20g/10 minutes. However, if the melting point is around 190°C or above 190°C, measure it under a load of 2160g at multiple temperatures above the melting point, and plot the reciprocal of the absolute temperature on the horizontal axis and the logarithm of the MFR on the vertical axis in a semilogarithmic graph. Expressed as a value extrapolated to 190°C.

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

[Hindered amine compound (B)]
The resin composition of the present invention contains 0.2 to 5 parts by weight of the hindered amine compound (B) based on 100 parts by weight of EVOH (A). When the resin composition of the present invention contains the hindered amine compound (B), it tends to be able to suppress deterioration of the hue after the weather resistance test, and when used in combination with the benzotriazole compound (C) described below, the weather resistance is significantly improved. Becomes good. The hindered amine compound (B) has a 2,2,6,6-tetraalkylpiperidine ring structure and an alkoxy group bonded to the 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., the following general formula (IV), molecular weight: 2800-4000), Hostavin NOW (manufactured by Clariant, chemical formula : General formula (I) below, molecular weight: about 2000), FLAMESTAB NOR 116 (manufactured by BASF Japan Co., Ltd., chemical formula: general formula (II) below, molecular weight: 2261), Chimassorb 2020 (manufactured by BASF Japan Co., 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 product s with N-butyl- 1-butanamine and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, molecular weight: 2600 to 3400), and TINUVIN NOR 371 is particularly preferred. Further, these hindered amine compounds (B) may be used alone or in combination of two or more types.

(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.)

(R ₂ in the above general formula (II) is a substituent shown in the following general formula (III), and the bonding site is on the triazine ring)

(R ₃ to R ₇ in the above general formula (IV) are arbitrary substituents, and whether they are different substituents or the same substituent, only some of the substituents are the same. good)

The molecular weight of the hindered amine compound (B) is preferably 1000 or more. When the molecular weight is 1000 or more, bleed-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. Furthermore, 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) will adhere to the mold of the molding machine. This may cause poor appearance on the surface of the molded product, and therefore, the molecular weight of the hindered amine compound (B) is preferably 1000 or more from the viewpoint of suppressing poor appearance. The molecular weight of the hindered amine compound (B) is more preferably 1,400 or more, even more preferably 1,700 or more, and particularly preferably 1,900 or more. The molecular weight of the hindered amine compound (B) may be 5000 or less.

The content of the hindered amine compound (B) in the resin composition of the present invention is 0.2 to 5 parts by weight based on 100 parts by weight 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. Furthermore, if the content is more than 5 parts by mass, the viscosity of the resin may 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.

[Benzotriazole compound (C)]
The resin composition of the present invention contains 0.1 to 5 parts by mass of a benzotriazole compound (C) per 100 parts by mass of EVOH (A). By containing the benzotriazole compound (C), the resin composition of the present invention tends to be able to suppress the increase in light transmittance (300 nm) after the weather resistance test, and by using it in combination with the hindered amine compound (B), The properties are markedly improved. The benzotriazole compound is not particularly limited as long as it has a benzotriazole skeleton, and any known compound can be used. From the viewpoint of further improving weather resistance, the benzotriazole compound (C) preferably has a structure in which a hydroxyl group is bonded to an aromatic ring, and such aromatic ring is bonded to a nitrogen atom constituting the benzotriazole ring. . Further, 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. Further, the aromatic ring to which the hydroxyl group is bonded preferably has two or more substituents in addition to the hydroxyl group and the benzotriazole ring. Further, the benzotriazole compound (C) preferably has a halogen group on the benzotriazole ring.

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

The content of the benzotriazole compound (C) in the resin composition of the present invention is 0.1 to 5 parts by weight based on 100 parts by weight 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. On the other hand, if the content of the benzotriazole compound (C) is more than 5 parts by mass, the film will be significantly colored after the 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.

The benzotriazole compound (C) may be used alone or in combination of two or more.

[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, 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. Moreover, when the mass ratio (C)/(B) is 3.5 or less, coloring of the film tends to be more suppressed. The mass ratio (C)/(B) is more preferably 3.0 or less, further preferably 2.0 or less, even more preferably 1.5 or less, and particularly preferably 1.0 or less.

The resin composition of the present invention includes boron compounds, carboxylic acids, phosphorus compounds, metal ions, antioxidants, It may also contain other components such as ultraviolet absorbers, plasticizers, antistatic agents, lubricants, colorants, fillers, heat stabilizers, and 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% by mass, and sometimes preferably 0.5% by mass.

The resin composition of the present invention preferably contains a boron compound as another component. This makes it possible to suppress torque fluctuations during heating and melting. The boron compound is not particularly limited, and includes boric acids, boric acid esters, borates, boron hydrides, and the like. Specifically, boric acids include orthoboric acid, metaboric acid, tetraboric acid, etc., boric acid esters include triethyl borate, trimethyl borate, etc., and borates include the various borates listed above. Examples include alkali metal salts of acids, alkaline earth metal salts, borax, and the like. 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. When the content of the boron compound is 50 ppm or more, melt moldability tends to be stable, and the content is more preferably 70 ppm or more, and even more preferably 100 ppm or more. On the other hand, when the boron compound content is 400 ppm or less, deterioration of moldability tends to be suppressed, and it is more preferably 350 ppm or less, and may be 300 ppm or less.

Carboxylic acids prevent coloring of the resin composition and thus the molded article, and also suppress gelation during melt molding. Examples of carboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, lactic acid, and salts thereof. As the carboxylic acids, carboxylic acids having 4 or less carbon atoms or saturated carboxylic acids are preferable, and acetic acids are more preferable. The acetic acids include acetic acid and acetate. As acetic acids, it is preferable to use acetic acid and acetate together, and it is more preferable to use acetic acid and sodium acetate together. When the resin composition of the present invention contains carboxylic acids, the lower limit of the content of carboxylic acids is preferably 50 ppm, more preferably 80 ppm, and even more preferably 120 ppm. Further, the upper limit of the content of carboxylic acids is preferably 1,000 ppm, more preferably 500 ppm, and even more preferably 400 ppm. By setting the content of carboxylic acids to the above lower limit or more, a sufficient effect of suppressing coloring can be obtained, and occurrence of yellowing can be sufficiently suppressed. On the other hand, by controlling the content of carboxylic acids to be less than or equal to the above upper limit, gelation is less likely to occur during melt molding, particularly during melt molding over a long period of time, and the appearance of the molded product etc. becomes good.

The phosphorus compound suppresses the occurrence of defects such as streaks and fish eyes, as well as coloring, and improves long-run performance. Examples of the phosphorus compound include phosphates such as phosphoric acid and phosphorous acid. The above-mentioned phosphate may be in the form of primary phosphate, secondary phosphate, or tertiary phosphate. The cation type of the phosphate is not particularly limited, but alkali metal salts and alkaline earth metal salts are preferred, and among these, sodium dihydrogen phosphate, potassium dihydrogen phosphate, dihydrogen phosphate, Compounds containing phosphate ions such as sodium 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 phosphate ion content 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 more than the above lower limit or less than the above upper limit, thermal stability is improved and gel-like lumps and discoloration are less likely to occur during long-term melt molding. .

Examples of metal ions include monovalent metal ions, divalent metal ions, and other transition metal ions, and these may be composed of one or more types. Among these, monovalent metal ions and divalent metal ions are preferred. As the monovalent metal ion, an alkali metal ion is preferable, such as lithium, sodium, potassium, rubidium, and cesium ions, and sodium or potassium ions are preferable from the viewpoint of industrial availability. Furthermore, examples of alkali metal salts that provide alkali metal ions include aliphatic carboxylates, aromatic carboxylates, carbonates, hydrochlorides, nitrates, sulfates, phosphates, and metal complexes. Among these, aliphatic carboxylates and phosphates are preferred because they are easily available, and specifically, sodium acetate, potassium acetate, sodium phosphate, and potassium phosphate are preferred. In some cases, it is preferable to include a divalent metal ion as the metal ion. If the metal ion contains a divalent metal ion, thermal deterioration of EVOH when the trim is collected and reused may be suppressed, and generation of gels and lumps in the resulting molded product 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, with carboxylates being preferred. The carboxylic acid constituting the carboxylic acid salt is preferably a carboxylic acid having 1 to 30 carbon atoms, and specific examples include acetic acid, propionic acid, butyric acid, stearic acid, lauric acid, montanic acid, behenic acid, octylic acid, and sebacic acid. Acids include ricinoleic acid, myristic acid, palmitic acid, etc., and among them, 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 alkali metal ion content 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 alkali metal ions is preferably 400 ppm, more preferably 350 ppm. When the content of alkali metal ions is at least the above lower limit, the resulting multilayer structure tends to have good interlayer adhesion. On the other hand, when the content of metal ions is below the above upper limit, coloring resistance tends to be good.

Examples of antioxidants 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, and the like. Examples of ultraviolet absorbers 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-oxytoxybenzophenone, etc. .

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

Examples of the lubricant include ethylene bisstearamide and butyl stearate. Examples of the coloring agent include carbon black, phthalocyanine, quinacridone, indoline, azo pigment, and red iron. 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.

Examples of resins other than EVOH (A) include polyamide, polyolefin, and the like.

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, and 98% by mass or more. is more preferable, and 99% by mass or more is particularly preferable. The resin composition of the present invention may be substantially composed only of EVOH (A), a hindered amine compound (B), and a benzotriazole compound (C), and the resin composition of the present invention may consist of only EVOH (A), a hindered amine compound (B), and a benzotriazole compound (C). , a hindered amine compound (B) and a benzotriazole compound (C). In this specification, the expression "substantially consists only of" means that the inclusion of optional components is permitted within the range that does not affect the effects of the present invention, and in this specification, the expression "consist only of..." means excluding arbitrary components other than impurities that are inevitably included.

The resin composition of ^the present invention has a weight average molecular weight ( It is preferable that the retention rate of Mw) is 90% or more. Here, the maintenance rate of weight average molecular weight (Mw) is the maintenance 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 / weather resistance Mw×100) before the test. The weight average molecular weight (Mw) retention rate is more preferably 93% or more, and even more preferably 95% or more. Further, the weight average molecular weight (Mw) retention rate after the weather resistance test may be 99.9% or less. When the Mw maintenance 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 maintenance rate can be measured by the methods described in Examples.

The resin composition of ^the present invention has a number average molecular weight ( It is preferable that the retention rate of Mn) is 80% or more. Here, the maintenance rate of number average molecular weight (Mn) is the maintenance rate (%) calculated by dividing Mn after the weather resistance test by Mn before the weather resistance test (Mn before the weather resistance test/weather resistance Mn×100) before the test. The retention rate of number average molecular weight (Mn) is more preferably 85% or more, and even more preferably 87% or more. Further, the retention rate of number average molecular weight (Mn) 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 weathering test tends to be good. The weather resistance test and the Mn retention rate can be measured by the methods described in Examples.

When the molecular weight retention rate of Mw and Mn is within the above range, the mechanical properties such as impact strength of the laminate are maintained high.

The resin composition of the present invention 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. , is preferable from the viewpoint of improving the weather resistance of the entire roll when the roll of the laminate is stored outdoors. The light transmittance (300 nm) is more preferably 30% or less, further preferably 10% or less, particularly preferably 5% or less. In addition, the light transmittance (300 nm) after a weather resistance test of 50 hours of light irradiation at 63° C. and 50% RH with an irradiation intensity of 1000 W/m ² is preferably 50% or less, more preferably 30% or less, and 10% or less. It is more preferably at most 8%, particularly preferably at most 8%. Difference in light transmittance before and after a weather resistance test in which light is irradiated for 50 hours at 63°C and 50% RH at an irradiation intensity of 1000 W/ ^m2 (transmittance after weather resistance test (%)) - (transmission before weather resistance test) The ratio (%) 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.

The resin composition of the present invention preferably has an impact strength of 17.5 kgf/cm or more, more preferably 19.0 kgf/cm or more, and 19.8 kgf/cm or more of the impact strength of a 100 μm thick film made of the resin composition of the present invention. More preferred. Further, the impact strength may be 25.0 kgf·cm or less. In addition, the impact strength after a weathering test of 50 hours of light irradiation at 63° C. and 50% RH with an irradiation intensity of 1000 W/m ² is preferably 17.5 kgf・cm or more, more preferably 18.0 kgf・cm or more, 18 .5 kgf·cm or more is more preferable, and 19.5 kgf·cm or more is particularly preferable. Impact strength can be measured by the method described in Examples.

Although the method for producing the resin composition of the present invention is not particularly limited, for example, various additives such as EVOH (A), a hindered amine compound (B), a benzotriazole compound (C), and the above-mentioned other components as necessary are added. It can be manufactured by mixing and melting and kneading. Specifically, it can be carried out using a known mixing device or kneading device such as a kneader router, an extruder, a mixing roll, a Banbury mixer, or the like. 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 of pre-containing EVOH (A) is not particularly limited, and for example, EVOH (A) pellets are immersed in a solution containing various additives and dried to pre-contain various additives in EVOH (A). be able to.

Further, the resin composition of the present invention can be manufactured by a manufacturing method including a step of passing through a masterbatch. A manufacturing method including a masterbatch process involves melting 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) in advance. A manufacturing method including a step of kneading to obtain a masterbatch and a step of melt-kneading the obtained masterbatch and EVOH (A) is preferred. By providing a step to obtain a masterbatch in advance, the hindered amine compound (B) and benzotriazole compound (C) are better dispersed in EVOH (A) than other mixing methods, and tend to have better weather resistance. . Note that 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 method for producing a resin composition of the present invention preferably includes a step of passing through a masterbatch from the viewpoint of further increasing the weather resistance of the resulting resin composition.

[Master Badge]
The masterbatch used in the method for producing a resin composition including the step of passing through the 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 a high concentration, and is used after being diluted with EVOH (A) to a specified ratio. It is used 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 2 to 3 parts of the hindered amine compound (B) is added to 100 parts by mass of EVOH (A). 20 parts by mass, and 1 to 15 parts by mass of benzotriazole compound (C). When the content of the hindered amine compound (B) and the benzotriazole compound (C) is within the above range, the masterbatch can be stably produced.

The method of incorporating the hindered amine compound (B) and the benzotriazole compound (C) into the masterbatch of the present invention is not particularly limited. For example, EVOH (A), the hindered amine compound (B), and the benzotriazole compound (C) ) are dry blended and then melt-kneaded in an extruder, EVOH (A) is immersed in a solution in which the hindered amine compound (B) and benzotriazole compound (C) are dissolved, and EVOH (A) is melted. A method of mixing a hindered amine compound (B) and a benzotriazole compound (C), a method of melt blending EVOH (A), a hindered amine compound (B), and a benzotriazole compound (C) in an extruder, etc. can be mentioned. Among these, a method in which EVOH (A), hindered amine compound (B), and benzotriazole compound (C) are dry blended and further melt-kneaded in an extruder is preferred.

[Laminated body]
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. A 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 in the laminate may be two layers or three layers. The upper limit of the number of layers in the laminate may be 1000 layers, 100 layers, or 10 layers. Furthermore, the laminate of the present invention may further include a layer formed from components other than resin, such as a layer formed from paper, a metal layer, and the like.

Examples of the layer 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 the layer consisting of the resin composition of the present invention is E, the layer obtained from the adhesive resin is Ad, and the layer obtained from the thermoplastic resin is T. For example, T/E/T, E/Ad/T, T/Ad/E/Ad/T, E/Ad/T/Ad/E, E/Ad/T/Ad. Examples include structures such as /E/Ad/T/Ad/E. Each of these layers may be a single layer or a multilayer. Note that layers other than those described above may be included as long as the effects of the present invention are not impaired. Examples of other layers include collection layers. In particular, the collected composition containing the recovered laminate of the present invention may be reused as part or all of the collected layer.

Examples of thermoplastic resins 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 (carbon Copolymers of 4 to 20 α-olefins; mono or copolymers of olefins such as polybutene and polypentene; polyesters such as polyethylene terephthalate; polyester elastomers; polyamides such as nylon-6 and nylon-66; polystyrene; Examples include vinyl chloride, polyvinylidene chloride, acrylic resin, vinyl ester resin, polyurethane elastomer, polycarbonate, chlorinated polyethylene, and chlorinated polypropylene. 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.

The adhesive resin is not particularly limited as long as it has adhesive properties with the gas barrier layer and layers made of other components, but adhesive resins containing carboxylic acid-modified polyolefin are preferred. The carboxylic acid-modified polyolefin is preferably a modified olefin-based polymer containing a carboxyl group in which an ethylenically unsaturated carboxylic acid, its ester, or its anhydride is chemically bonded to the olefin-based polymer, and maleic anhydride-modified olefins are preferred. type polymers are 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 these, 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.

The method for producing the laminate of the present invention is not particularly limited, and examples include a method of melt-extruding other components into a molded article (film, sheet, etc.) made of the resin composition of the present invention, and a method of melt-extruding the resin composition of the present invention and other components. a method of co-injection molding the resin composition of the present invention and other components; a method of co-injection molding the resin composition of the present invention and a layer of other components; , a method of laminating using a known adhesive such as a polyester compound, and the like.

The method for coextruding the resin composition of the present invention and other components is not particularly limited, and examples thereof include a multi-manifold confluence T-die method, a feedblock confluence T-die method, an inflation method, and the like.

[Application]
The resin composition of the present invention has very good weather resistance and excellent manufacturing stability, and is suitable for use in industrial films and pipes that have a gas barrier layer made of such a resin composition. It is. 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 provides agricultural films (preferably soil fumigation films, silage films, or greenhouse films), grain storage bags, geomembranes, pipes (preferably hot water circulation films) having gas barrier layers made of the resin composition of the present invention. pipes for fuel use or fuel pipes).

The resin composition of the present invention can be used as a soil fumigation film used to prevent transpiration of chloropicrin, methyl bromide, etc. used as soil fumigants, and as a silage film for wrapping silage that becomes acidic due to fermentation. This is especially useful when Under these conditions, the resin composition of the present invention will be exposed to acidic conditions due to the agent or silage. If the film is used outdoors for a long period of time under acidic conditions, the deterioration of the film will be accelerated, but even under such conditions, the soil fumigation film and silage film made of the resin composition of the present invention have excellent weather resistance. In good condition.

The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto. The methods of measurement, calculation, and evaluation were as follows.

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

[Evaluation method]
(1) Measurement of phosphate ion, alkali metal ion, and boron element content 0.5 g of the resin composition pellets obtained in the Examples and Comparative Examples were placed in a Teflon (registered trademark) pressure vessel, and 5 mL of concentrated nitric acid was placed therein. was added and allowed to decompose at room temperature for 30 minutes. After 30 minutes, the lid was closed and decomposition was performed by heating at 150°C for 10 minutes and then at 180°C for 5 minutes using a wet decomposition device (manufactured by Actac Co., Ltd.: "speedwave 4"), and then cooled to room temperature. This treated solution was transferred to a 50 mL volumetric flask (manufactured by TPX) and diluted with pure water. This solution was analyzed for metal content using an ICP emission spectrometer (PerkinElmer's "Avio500"), and the contents of phosphate ions, sodium metal ions, and boron elements were measured.

(2) Quantification of acetic acid 20 g of the resin composition pellets obtained in Examples and Comparative Examples were put into 100 ml of ion-exchanged water, and extracted by heating at 95° C. for 6 hours. Using phenolphthalein as an indicator, the extract was neutralized and titrated with 1/50 normal NaOH to quantify the acetic acid content.

(3) Weather resistance test The single-layer films obtained in Examples and Comparative Examples were tested using an eye super UV tester "SUV-W15" manufactured by Iwasaki Electric Co., Ltd. at an irradiance of 1000 W/m ² and a black panel temperature of 63°C. An accelerated weathering test was conducted for 50 hours at a relative humidity of 50%, and the following (4) molecular weight retention rate, (5) light transmittance, (6) impact strength, and (7) film coloration were evaluated before and after the test. did.

(4) Molecular weight maintenance rate The weight average molecular weight (Mw) and number average molecular weight (Mn) of the single layer film before and after the weather resistance test were measured by gel permeation chromatography (GPC). Note that the measurement conditions are as follows.
Equipment: Gel permeation chromatography “HLC-8320” manufactured by Tosoh Corporation
Column: 2 “GMHHR-H(S)” manufactured by Tosoh Corporation Column temperature: 40°C
Mobile phase: hexafluoroisopropanol + 20mM CF ₃ COONa, flow rate: 0.2mL/min Detector: RI, sample concentration: 0.1% by weight (hexafluoroisopropanol solution)
Based on the measurement results, calculate the Mw maintenance rate (%) by dividing the difference in Mw before and after the weather resistance test ((Mw before the weather resistance test) - (Mw after the weather resistance test)) by the Mw before the weather resistance test. (((Mw before weathering test)-(Mw after weathering test))/(Mw before weathering test)×100) was calculated. Similarly, the Mn retention rate (%) (( (Mn before weather resistance test) - (Mn after weather resistance test))/(Mn before weather resistance test) x 100) was calculated.

(5) Light transmittance The light transmittance at a wavelength of 300 nm was measured for the single-layer films obtained in Examples and Comparative Examples using an ultraviolet-visible spectrophotometer "UV-2450" 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.

(6) Impact strength The single-layer films obtained in Examples and Comparative Examples were conditioned for 24 hours at 23°C and 50% RH, and then the impact strength was measured using a film impact tester under the same conditions. . The measurement was performed five times at different locations, and the average value was used as the measurement result.

(7) Coloring The monolayer films obtained in Examples and Comparative Examples were visually observed and the degree of yellowing was evaluated using the following criteria. Among the following criteria, A, B, and C were determined to be at a usable level.
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.

Example 1
Water-containing EVOH pellets with an ethylene unit content of 38 mol% and a saponification degree of 99.9 mol% were immersed in an aqueous solution containing acetic acid, phosphoric acid, sodium acetate, and boric acid with stirring at 25°C for 6 hours, and then desorbed. After draining and drying in a hot air dryer (Yamato Scientific Co., Ltd. "DN6101") at 80°C for 4 hours, drying at 120°C for 40 hours, dry EVOH pellets (EVOH-1, moisture content 0.25%, MFR (190°C, under 2160g load) 1.7g/10 minutes) was obtained. The concentrations of acetic acid, phosphoric acid, sodium acetate, and boric acid in the resin composition obtained in this example are as follows: acetic acid content is 100 ppm, phosphate ion content is 40 ppm, and sodium ion content is 150 ppm. , the boron element was adjusted appropriately so that it was 180 ppm.

For 100 parts by mass of the obtained dry EVOH pellets, 0.4 parts by mass of Tinuvin NOR 371 (B-1) (manufactured by BASF Japan Co., Ltd.), 0 parts by mass of ADEKA STAB LA-36 (C-1) (manufactured by ADEKA Co., Ltd.) 3 parts by mass were dry blended, melted and kneaded under the following conditions using a 25 mm extruder "2D30W2" manufactured by Toyo Seiki Seisakusho Co., Ltd., and then pelletized to obtain resin composition pellets. Regarding the obtained resin composition pellets, the phosphate ion, alkali metal ion, and boron element contents were measured by the method described in the evaluation method (1) above, and the phosphate ion content was 40 ppm and the sodium ion content was 40 ppm. was 150 ppm, and boron element was 180 ppm.
Set temperature C1/C2/C3/C4/C5/Die=180/210/210/210/210/210℃
Screw rotation speed: 100rpm
Discharge amount: 6.0kg/hour

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

Examples 2 to 12, Comparative Examples 1 to 10
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. Resin composition pellets and single-layer films were produced and evaluated in the same manner. The results are shown in Table 1.

The single-layer films obtained in Example 1 and Comparative Example 1 were subjected to a weather resistance test according to the method described in evaluation method (3) above, and then subjected to oxygen permeation test according to JIS K 7126:2006 (isobaric method). The degree of The single-layer film obtained in Example 1 had a lower (superior) oxygen permeability than the single-layer film obtained in Comparative Example 1 after the weather resistance test. Example 1 contains specific amounts of the hindered amine compound (B) and benzotriazole compound (C), so compared to Comparative Example 1 which does not contain the hindered amine compound (B) and benzotriazole compound (C). It is presumed that it has excellent weather resistance and was able to maintain sufficient oxygen permeability even after the weather resistance test.

Example 13
In Example 1, dry EVOH pellets (EVOH-2 ), resin composition pellets and monolayer films were produced and evaluated. The results are shown in Table 1.

Example 14
To 93.5 parts by mass of the dry EVOH pellets obtained in Example 1, 3.7 parts by mass of Tinuvin NOR 371 (B-1, manufactured by BASF Japan Co., Ltd.), Adekastab LA-36 (C-1, manufactured by BASF Japan Co., Ltd.) (manufactured by ADEKA) were dry blended, melted and kneaded under the following conditions using a 25 mm extruder "2D30W2" manufactured by Toyo Seiki Seisakusho Co., Ltd., and then pelletized to obtain masterbatch pellets.
Set temperature: C1/C2/C3/C4/C5/Die=180/210/210/210/210/210℃
Screw rotation speed: 100rpm
Discharge amount: 6.0kg/hour

Furthermore, after dry blending 90 parts by mass of the dry EVOH pellets obtained in Example 1 and 10 parts by mass of masterbatch pellets, a single-layer film was formed in the same manner as in Example 1 and evaluated. The results are shown in Table 1.

Regarding the dried EVOH obtained in Example 1 and the masterbatch pellets obtained above, the phosphate ion, alkali metal ion, boron element, and acetic acid contents were evaluated by the methods described in evaluation methods (1) and (2) above. As a result of measurement, the contents contained in the dried EVOH pellets and masterbatch pellets were as follows: 40 ppm of phosphate ion content, 150 ppm of sodium ion content, 180 ppm of boron element, and 100 ppm of acetic acid content. From the above results, it was determined that the dry blend product also contained the same amounts of phosphate ions, sodium ions, elemental boron, and acetic acid as described above.

Example 15
The intermediate layer was made of the resin composition pellets of Example 1, the thermoplastic resin layer was made of polyethylene "Novatec (trademark) PE LF128" (PE) made by Japan Polyethylene Co., Ltd., and the adhesive layer was made of adhesive polyolefin "Admer (trademark) made by Mitsui Chemicals Co., Ltd. ) NF518'' (Ad), a laminate of 3 types and 5 layers (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 was an extruder having a film-forming die, followed by a take-up roll whose temperature could be controlled, and the obtained multilayer structure was wound up with the winder.
<Film forming conditions>
Extruder for resin composition pellets: Single screw extruder (Labo machine ME type CO-EXT, manufactured by Toyo Seiki Co., Ltd.)
Diameter 20mmφ, L/D=20, screw full flight type Supply section/compression section/measuring section/die=180/210/210/210℃
Extruder for PE: Single screw extruder (GT-32-A, manufactured by Plastic Engineering Research Institute Co., Ltd.)
Diameter 32mmφ, L/D=28, screw full flight type Supply section/compression section/measuring section/die=180/220/220/220℃
Extruder for Ad: Single screw extruder (SZW20GT-20MG-STD, manufactured by Technovel Co., Ltd.)
Diameter 20mmφ, L/D=20, screw full flight type Supply section/compression section/measuring section/die=180/220/220/220℃
Die: 300mm width coat hanger die (manufactured by Plastic Engineering Research Institute)
Take-up roll temperature: 60℃

The obtained multilayer structure had excellent weather resistance and exhibited satisfactory performance even when stored outdoors for a long period of time.

Claims (15)

Ethylene-vinyl alcohol copolymer (A) with an ethylene unit content of 20 to 60 mol%,
a hindered amine compound (B) having a 2,2,6,6-tetraalkylpiperidine ring structure and an alkoxy group bonded to the nitrogen atom in the structure;
and a benzotriazole compound (C),
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) per 100 parts by mass of the ethylene-vinyl alcohol copolymer (A). resin composition. The resin composition according to claim 1, wherein the mass ratio (C)/(B) of the benzotriazole compound (C) and the hindered amine compound (B) is 0.2 to 3.5. The resin composition according to claim 1 or 2, wherein the hindered amine compound (B) has a molecular weight of 1000 or more. Any one of claims 1 to 3, wherein the benzotriazole compound (C) has a structure in which a hydroxyl group is bonded to an aromatic ring, and the aromatic ring is bonded to a nitrogen atom constituting the benzotriazole ring. The resin composition described in . The resin composition according to claim 4, wherein the aromatic ring to which the hydroxyl group is bonded has two or more substituents in addition to the benzotriazole ring and the hydroxyl group. The resin composition according to any one of claims 1 to 5, wherein the benzotriazole compound (C) has a halogen group on the benzotriazole ring. The resin composition according to any one of claims 1 to 6, further comprising 5 ppm to 200 ppm of phosphate ions and 10 ppm to 400 ppm of alkali metal ions. The resin composition according to any one of claims 1 to 7, further comprising 50 to 400 ppm of a boron compound in terms of boron element. A film having a thickness of 100 μm made of the resin composition according to any one of claims 1 to 8 has a light transmittance of 50% or less at a wavelength of 300 nm measured in accordance with JIS K 7361-1:1997. , the resin composition according to any one of claims 1 to 8. Regarding a film having a thickness of 100 μm made of the resin composition according to any one of claims 1 to 9, the light transmittance at a wavelength of 300 nm measured in accordance with JIS K 7361-1:1997 was determined at 63° C. and 50 μm. Difference in light transmittance before and after a weather resistance test of 50 hours of light irradiation at an irradiation intensity of 1000 W/ ^m2 under %RH (transmittance after weather resistance test (%)) - (transmittance before weather resistance test (%)) ) is 4.0% or less, the resin composition according to any one of claims 1 to 9. A laminate comprising a layer made of the resin composition according to any one of claims 1 to 10. An industrial film comprising the laminate according to claim 11. A pipe comprising the laminate according to claim 11. A masterbatch for producing the resin composition according to any one of claims 1 to 10,
Ethylene-vinyl alcohol copolymer (A) having an ethylene unit content of 20 to 60 mol%, an alkoxy compound having a 2,2,6,6-tetraalkylpiperidine ring structure and bonded to the nitrogen atom in the structure containing a hindered amine compound (B) having a group 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) based on 100 parts by mass of the ethylene-vinyl alcohol copolymer (A). . 100 parts by mass of an ethylene-vinyl alcohol copolymer (A) having an ethylene unit content of 20 to 60 mol%, having a 2,2,6,6-tetraalkylpiperidine ring structure, and a nitrogen atom in the structure Obtaining a masterbatch by melt-kneading 2 to 20 parts by mass of a hindered amine compound (B) having a bonding alkoxy group and 1 to 15 parts by mass of a benzotriazole compound (C);
The obtained masterbatch and the ethylene-vinyl alcohol copolymer (A) are melt-kneaded, and 0.0% of the hindered amine compound (B) is added to 100 parts by mass of the ethylene-vinyl alcohol copolymer (A). 2 to 5 parts by mass of the benzotriazole compound (C), and obtaining a resin composition containing 0.1 to 5 parts by mass of the benzotriazole compound (C).