Resin compositions, single-layer films, and laminates

Abstract

To provide a resin composition that is a resin composition containing an ethylene-vinyl alcohol copolymer (EVOH) in which neck-in and die-buildup when forming a melt is suppressed.SOLUTION: A resin composition containing EVOH (A), inorganic particles (D) and crotonaldehyde (B1), and at least one selected from the group consisting of 2,4-hexadienal (B2) and 2,4,6-octatrienal (B3) and satisfying further the following formulas (1) and (2). In formulas (1) and (2), b1 is a content (ppm) of crotonaldehyde (B1) relative to EVOH (A), and b2 is a content (ppm) of 2,4-hexadienal (B2) relative to EVOH (A), and b3 is the content (ppm) of 2,4,6-octatrienal (B3) relative to EVOH (A). 2.0≤b1 / (b2+b3)<150.0 (1) b2+2b3≤0.65 (2)SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to resin compositions, single-layer films, and laminates. [Background technology]

[0002] Ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as "EVOH") is a polymer material with excellent gas barrier properties such as oxygen, oil resistance, antistatic properties, mechanical strength, and melt moldability. For this reason, EVOH resin compositions are widely used as molding materials for containers, sheets, films, etc. In addition, EVOH resin compositions containing inorganic particles may be used as molding materials for base films of inorganic vapor-deposited films. Melt molding is generally used for molding films, containers, etc. Therefore, resin compositions used for melt molding need to have excellent long-run performance, such as not developing defects like fisheyes or streaks even after prolonged melt molding.

[0003] However, because EVOH has relatively active hydroxyl groups within its molecule, oxidation and crosslinking reactions can proceed in a high-temperature molten state even inside an extrusion molding machine where there is almost no oxygen, potentially generating thermally degraded products. In particular, during long-term continuous operation, these thermally degraded products can accumulate inside the molding machine, generating gel-like particles that cause fish eyes, which can result in EVOH resin compositions having insufficient long-run performance.

[0004] In contrast, Patent Document 1 describes a resin composition containing EVOH and 0.01 to 100 ppm of unsaturated aldehydes that suppresses the occurrence of defects such as fish eyes, gels, and streaks, and exhibits excellent long-run performance. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2013 / 146961 [Overview of the project] [Problems that the invention aims to solve]

[0006] When using the EVOH resin composition described in Patent Document 1, it was found that neck-in, where the width of the extruded film is smaller than the effective width of the die, can occur during film molding with a T-die. Furthermore, it was found that EVOH resin compositions prone to such neck-in tend to have uneven thickness in the width direction of the formed layer, and as a result, films obtained using this EVOH resin composition tend to have non-uniform gas barrier properties in different parts. After diligent research by the inventors, it was surprisingly discovered that an EVOH resin composition containing specific types of unsaturated aldehydes in specific ratios can suppress such neck-in. However, when attempting to suppress neck-in by adjusting the content of the multiple types of unsaturated aldehydes, it was found that depending on the ratio of the multiple types of unsaturated aldehydes, a new problem arises: die build-up (deposits on the outer surface of the die lip) tends to adhere to the outer surface of the discharge port (die lip) of the molten resin composition.

[0007] On the other hand, in recent years, due to the diversification of layer configurations and the synergistic effect of improving barrier properties through lamination with inorganic vapor-deposited layers, there has been an increase in cases where multilayer structures are manufactured by co-extruding the EVOH layer as the outermost layer. The occurrence of die build-up described above can be a significant problem when the area in contact with the die lip of EVOH is large, when the EVOH layer is co-extruded as the outermost layer of a multilayer structure, and when it is a single-layer film consisting only of the EVOH layer. Furthermore, it has been found that single-layer films obtained using EVOH resin compositions that are prone to such die build-up are more susceptible to defects such as streaks caused by die build-up, which can lead to defects when inorganic vapor deposition is performed and a decrease in the adhesion of the inorganic vapor-deposited layer.

[0008] The present invention has been made based on such circumstances, and its object is to provide a resin composition containing EVOH, in which neck-in and die build-up during melt molding are suppressed, and a single-layer film and a laminate using the same.

Means for Solving the Problems

[0009] The above object is achieved by [1] A resin composition containing an ethylene-vinyl alcohol copolymer (A) (hereinafter sometimes abbreviated as "EVOH (A)") having an ethylene unit content of 20 mol% or more and 60 mol% or less, inorganic particles (D), and crotonaldehyde (B1), further containing at least one selected from the group consisting of 2,4-hexadienal (B2) and 2,4,6-octatrieneal (B3), wherein the content (d) of the inorganic particles (D) with respect to EVOH (A) is 50 ppm or more and 5,000 ppm or less, and satisfying the following formulas (1) and (2); 2.0 ≦ b1 / (b2 + b3) < 150.0 ···(1) b2 + 2b3 ≦ 0.65 ···(2) In the above formulas (1) and (2), b1 is the content (ppm) of crotonaldehyde (B1) with respect to EVOH (A), b2 is the content (ppm) of 2,4-hexadienal (B2) with respect to EVOH (A), and b3 is the content (ppm) of 2,4,6-octatrieneal (B3) with respect to EVOH (A). [2] The resin composition according to [1], wherein the total content (b1 + b2 + b3) of crotonaldehyde (B1), 2,4-hexadienal (B2), and 2,4,6-octatrieneal (B3) with respect to EVOH (A) is 0.01 ppm or more and 7.0 ppm or less; [3] The resin composition according to [1] or [2], wherein the content b1 of crotonaldehyde (B1) is 0.01 ppm or more and 4.0 ppm or less; [4] The resin composition according to any one of [1] to [3], wherein the content b2 of 2,4-hexadienal (B2) is 0.005 ppm or more and 0.65 ppm or less; [5] A resin composition of any of [1] to [4], wherein the content of 2,4,6-octatrienal (B3) is 0.325 ppm or less; [6] A resin composition according to any of [1] to [5], further comprising a conjugated polyene compound (C), wherein the content c of the conjugated polyene compound (C) relative to EVOH (A) is 1 ppm or more and less than 300 ppm; [7] A resin composition of [6] wherein the conjugated polyene compound (C) is sorbic acid; [8] A resin composition of any of [1] to [7] wherein EVOH(A) contains EVOH(Aa) and EVOH(Ab), the melting point difference between EVOH(Aa) and EVOH(Ab) (Aa-Ab) is 8°C or more, and the mass ratio of EVOH(Aa) to EVOH(Ab) (Aa / Ab) is 60 / 40 or more and 95 / 5 or less; [9] The resin composition of [8] wherein the ethylene unit content of EVOH(Aa) is 20 mol% or more and 50 mol% or less, the ethylene unit content of EVOH(Ab) is 30 mol% or more and 60 mol% or less, and the difference in ethylene unit content between EVOH(Ab) and EVOH(Aa) (Ab-Aa) is 4.5 mol% or more; A single-layer film made of any of the resin compositions

[10] [1] to [9];

[11] A biaxially oriented film, a single layer film of

[10] ; A laminate having a single-layer film of

[12]

[10] or

[11] and other layers;

[13] Laminate, in which the other layers are inorganic vapor-deposited layers;

[12] This is achieved by providing [the necessary services / services]. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a resin composition containing EVOH in which neck-in and die build-up during melt molding are suppressed, as well as a molded article and a multilayer structure using the same. [Modes for carrying out the invention]

[0011] <Resin composition> The resin composition of the present invention comprises EVOH (A), inorganic particles (D), and crotonaldehyde (B1), and further comprises at least one selected from the group consisting of 2,4-hexadienal (B2) and 2,4,6-octatrienal (B3), wherein the content (d) of inorganic particles (D) relative to EVOH (A) is 50 ppm or more and 5,000 ppm or less, and satisfies the following formulas (1) and (2). 2.0≦b1 / (b2+b3)<150.0 (1) b² + 2b³ ≤ 0.65 ···(2) In formulas (1) and (2) above, b1 is the content of crotonaldehyde (B1) relative to EVOH (A) (ppm), b2 is the content of 2,4-hexadienal (B2) relative to EVOH (A) (ppm), and b3 is the content of 2,4,6-octatrienal (B3) relative to EVOH (A) (ppm). In this specification, the content expressed in ppm is the content on a mass basis.

[0012] A b1 / (b2+b3) value of 2.0 or more and less than 150.0 results in good neck-in resistance, and the uniformity of gas barrier properties tends to improve, such as by reducing thickness variations in the resulting film or other layers. On the other hand, 2,4-hexadienal (B2) and 2,4,6-octatrienal (B3) affect die build-up, and 2,4,6-octatrienal (B3) has a particularly large effect on die build-up. Therefore, a b2+2b3 value of 0.65 ppm or less suppresses die build-up, and the adhesion between the inorganic vapor-deposited layer and the resulting film tends to improve. For this reason, the resin composition of the present invention can be suitably used as a melt molding material. In this specification, crotonaldehyde (B1), 2,4-hexadienal (B2), and 2,4,6-octatrienal (B3) may be collectively referred to as unsaturated aliphatic aldehyde (B). Furthermore, by including a predetermined amount of inorganic particles (D) in the resin composition of the present invention, the adhesion between the inorganic vapor-deposited layer and the resulting film, and the tear resistance of the resulting film can be improved.

[0013] (EVOH(A)) EVOH(A) is a copolymer having ethylene units and vinyl alcohol units, with an ethylene unit content of 20 mol% to 60 mol%. EVOH(A) is usually obtained by saponification of an ethylene-vinyl ester copolymer. The production and saponification of ethylene-vinyl ester copolymers can be carried out by known methods. Examples of vinyl esters include vinyl acetate, vinyl formate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl pivalate, vinyl versaticate, and other aliphatic carboxylic acid vinyl esters, with vinyl acetate being preferred.

[0014] The ethylene unit content of EVOH(A) is 20 mol% or more, preferably 25 mol% or more, and more preferably 27 mol% or more. The ethylene unit content of EVOH(A) is 60 mol% or less, preferably 55 mol% or less, and more preferably 50 mol% or less. If the ethylene unit content is less than 20 mol%, the thermal stability during melt extrusion decreases, gelation becomes more likely, and streaks, fish eyes, and other defects tend to occur. The occurrence of streaks, fish eyes, and other defects becomes particularly noticeable when operating at higher temperatures or speeds for longer periods than under general conditions. If the ethylene unit content exceeds 60 mol%, the gas barrier properties tend to decrease.

[0015] The degree of saponification of EVOH(A) is preferably 90 mol% or higher, more preferably 95 mol% or higher, and even more preferably 99 mol% or higher. When the degree of saponification of EVOH(A) is 90 mol% or higher, the gas barrier properties, thermal stability, moisture resistance, etc., tend to be good in the resin composition of the present invention and in various molded articles such as films obtained from the resin composition of the present invention. Furthermore, the degree of saponification may be 100 mol% or less, 99.97 mol% or less, or 99.94 mol% or less.

[0016] Furthermore, EVOH(A) may have other structural units other than ethylene units, vinyl alcohol units, and vinyl ester units, to the extent that the objectives of the present invention are not hindered. When EVOH(A) has the above-mentioned other structural units, the content of these other structural units relative to the total structural units of EVOH(A) is preferably 30 mol% or less, more preferably 20 mol% or less, even more preferably 10 mol% or less, even more preferably 5 mol% or less, and particularly preferably 1 mol% or less. Also, when EVOH(A) has the above-mentioned other structural units, their content may be 0.05 mol% or more, or 0.10 mol% or more. Other structural units mentioned above include, for example, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, and itaconic acid, or their anhydrides, salts, or mono- or dialkyl esters; nitriles such as acrylonitrile and methacrylonitrile; amides such as acrylamide and methacrylamide; olefin sulfonic acids such as vinyl sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid, or their salts; vinylsilane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(β-methoxy-ethoxy)silane, and γ-methacryloxypropylmethoxysilane; and structural units derived from alkyl vinyl ethers, vinyl ketones, N-vinylpyrrolidone, vinyl chloride, vinylidene chloride, etc.

[0017] The above-mentioned other structural units may be at least one of the following: structural unit (I) represented by formula (I), structural unit (II) represented by formula (II), and structural unit (III) represented by formula (III).

[0018] [ka]

[0019] In equations (I), (II), and (III), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R9 , R 10 and R 11 each independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or a hydroxyl group. Also, R 1 , R 2 and R 3 one pair of, R 4 and R 5 , R 6 and R 7 may combine to form part of a ring structure. Some or all of the hydrogen atoms of the above aliphatic hydrocarbon group having 1 to 10 carbon atoms, alicyclic hydrocarbon group having 3 to 10 carbon atoms, and aromatic hydrocarbon group having 6 to 10 carbon atoms may be substituted with a hydroxyl group, an alkoxy group, a carboxyl group, or a halogen atom. In formula (III), R 12 and R 13 each independently represents a hydrogen atom, a formyl group, or an alkanoyl group having 2 to 10 carbon atoms.

[0020] When EVOH (A) has the above structural unit (I), (II), or (III), the flexibility and processing characteristics of the resin composition are improved, and the stretchability and thermoformability, etc. in various molded articles such as films and laminates obtained tend to be good.

[0021] In the above structural unit (I), (II), or (III), examples of the aliphatic hydrocarbon group having 1 to 10 carbon atoms include an alkyl group, an alkenyl group, etc.; examples of the alicyclic hydrocarbon group having 3 to 10 carbon atoms include a cycloalkyl group, a cycloalkenyl group, etc.; and examples of the aromatic hydrocarbon group having 6 to 10 carbon atoms include a phenyl group, etc.

[0022] In the above structural unit (I), the above R 1 , R 2 and R 3Preferably, each of these groups is independently a hydrogen atom, a methyl group, an ethyl group, a hydroxyl group, a hydroxymethyl group, or a hydroxyethyl group. Among these, it is more preferable that each group is independently a hydrogen atom, a methyl group, a hydroxyl group, or a hydroxymethyl group, from the viewpoint of further improving the moldability of the resin composition and the stretchability and thermoformability of the resulting films, laminates, and other molded articles.

[0023] The method for incorporating the above structural unit (I) into EVOH(A) is not particularly limited, and examples include copolymerizing monomers induced to structural unit (I) in the polymerization of ethylene and vinyl ester. Monomers derived to structural unit (I) include alkenes such as propylene, butylene, pentene, and hexene; 3-hydroxy-1-propene, 3-acyloxy-1-propene, 3-acyloxy-1-butene, 4-acyloxy-1-butene, 3,4-diasiloxy-1-butene, 3-acyloxy-4-hydroxy-1-butene, 4-acyloxy-3-hydroxy-1-butene, 3-acyloxy-4-methyl-1-butene, 4-acyloxy-2-methyl-1-butene, 4-acyloxy-3-methyl-1-butene, 3,4-diasiloxy-2-methyl-1-butene, 4-hydroxy-1-pentene, 5-hydroxy-1-pentene, 4 Examples of alkenes having a hydroxyl group or ester group include 5-dihydroxy-1-pentene, 4-acyloxy-1-pentene, 5-acyloxy-1-pentene, 4,5-diasiloxy-1-pentene, 4-hydroxy-3-methyl-1-pentene, 5-hydroxy-3-methyl-1-pentene, 4,5-dihydroxy-3-methyl-1-pentene, 5,6-dihydroxy-1-hexene, 4-hydroxy-1-hexene, 5-hydroxy-1-hexene, 6-hydroxy-1-hexene, 4-acyloxy-1-hexene, 5-acyloxy-1-hexene, 6-acyloxy-1-hexene, and 5,6-diasiloxy-1-hexene. In particular, propylene, 3-acyloxy-1-propene, 3-acyloxy-1-butene, 4-acyloxy-1-butene, and 3,4-diasiloxy-1-butene are preferred from the viewpoint of copolymerization reactivity and the processability and gas barrier properties of the various molded articles obtained. Note that "acyloxy" is preferably acetoxy, specifically 3-acetoxy-1-propene, 3-acetoxy-1-butene, 4-acetoxy-1-butene, and 3,4-diacetoxy-1-butene. In the case of alkenes containing esters, they are converted to the above structural unit (I) during the saponification reaction.

[0024] In the above structural unit (II), R 4 and R 5It is preferable that both are hydrogen atoms. In particular, R 4 and R 5 Both are hydrogen atoms, and the above R 6 and R 7 It is more preferable that one of them is an aliphatic hydrocarbon group having 1 to 10 carbon atoms and the other is a hydrogen atom. The aliphatic hydrocarbon group is preferably an alkyl group or an alkenyl group. From the viewpoint of particularly emphasizing the gas barrier properties of the resulting multilayer structures and other molded articles, R 6 and R 7 It is more preferable that one of them is a methyl group or an ethyl group and the other is a hydrogen atom. Also, the above R 6 and R 7 One of them is (CH2) h It is even more preferable that the substituent is represented by OH (where h is an integer from 1 to 8), and the other atom is a hydrogen atom. (CH2) h In substituents represented by OH, h is preferably an integer from 1 to 4, more preferably 1 or 2, and even more preferably 1.

[0025] The method for incorporating the above structural unit (II) into EVOH(A) is not particularly limited. For example, a method of incorporating it by reacting EVOH(A) obtained by a saponification reaction with a monovalent epoxy compound can be used. As the monovalent epoxy compound, compounds represented by the following formulas (IV) to (X) are preferably used.

[0026] [ka]

[0027] In the above equations (IV) to (X), R 14 , R 15 , R 16 , R 17 and R 18Each of these independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms (alkyl groups, alkenyl groups, etc.), an alicyclic hydrocarbon group having 3 to 10 carbon atoms (cycloalkyl groups, cycloalkenyl groups, etc.), or an aliphatic hydrocarbon group having 6 to 10 carbon atoms (phenyl groups, etc.). Also, i, j, k, p, and q each independently represent an integer from 1 to 8. However, R 17 If R is a hydrogen atom, 18 It is a group other than a hydrogen atom.

[0028] Examples of monovalent epoxy compounds represented by formula (IV) above include 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-epoxypropane, 3-phenyl-1,2-epoxypropane, etc. Examples of monovalent epoxy compounds represented by formula (V) above include various alkylglycidyl ethers, etc. Examples of monovalent epoxy compounds represented by formula (VI) include various alkylene glycol monoglycidyl ethers. Examples of monovalent epoxy compounds represented by formula (VII) include various alkenyl glycidyl ethers. Examples of monovalent epoxy compounds represented by formula (VIII) include various epoxy alkanols such as glycidol. Examples of monovalent epoxy compounds represented by formula (IX) include various epoxycycloalkanes. Examples of monovalent epoxy compounds represented by formula (X) include various epoxycycloalkenes.

[0029] Among the monovalent epoxy compounds mentioned above, epoxy compounds having 2 to 8 carbon atoms are preferred. Particularly from the viewpoint of ease of handling and reactivity, monovalent epoxy compounds having 2 to 6 carbon atoms are more preferred, and 2 to 4 carbon atoms are even more preferred. Furthermore, it is especially preferred that the monovalent epoxy compound is a compound represented by formula (IV) or formula (V) above. Specifically, from the viewpoint of reactivity with EVOH(A), processability of the resin composition and various molded articles such as the resulting film, and gas barrier properties, 1,2-epoxybutane, 2,3-epoxybutane, epoxypropane, epoxyethane, or glycidol are preferred, with epoxypropane or glycidol being more preferred among them.

[0030] In the above structural unit (III), R 8 , R 9 , R 10 and R 11 The aliphatic hydrocarbon group is preferably a hydrogen atom or an aliphatic hydrocarbon group having 1 to 5 carbon atoms, and such aliphatic hydrocarbon group is preferably a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, or n-pentyl group.

[0031] The method for incorporating the above structural unit (III) into EVOH(A) is not particularly limited, and for example, the method described in Japanese Patent Application Publication No. 2014-034647 can be cited.

[0032] The lower limit of the melting point of EVOH(A) is preferably 140°C, more preferably 150°C, and even more preferably 160°C. On the other hand, the upper limit of the melting point is preferably 220°C, more preferably 210°C, and even more preferably 200°C. When the melting point of EVOH(A) is within the above range, melt moldability is improved, and neck-in and die build-up during melt molding tend to be further suppressed. The melting point of EVOH(A) can be the value measured by the method described in the examples.

[0033] EVOH(A) may be used alone or in combination of two or more types.

[0034] Preferably, EVOH(A) contains two types of EVOH(Aa) and EVOH(Ab) with different melting points. For example, when the melting point of the resin composition of the present invention is measured by the method described in the examples, peak temperatures corresponding to each EVOH may be observed. Furthermore, the resin composition may have a phase-separated structure in which one EVOH is dispersed in the other, or it may be in a form in which the two types of EVOH are completely miscible. EVOH(Aa) and EVOH(Ab) may be two types of EVOH with different ethylene unit contents.

[0035] The lower limit of the difference in melting points between EVOH(Aa) and EVOH(Ab) (Aa-Ab), that is, the value obtained by subtracting the melting point of EVOH(Ab) from the melting point of EVOH(Aa), may be, for example, 5°C, but 8°C is preferred. When this melting point difference is 8°C or higher, moldability and other properties are improved, and the appearance is good when obtaining films etc. from the resin composition. The lower limit of this melting point difference is more preferably 12°C, even more preferably 16°C, even more preferably 20°C, and even more preferably 24°C. The lower limit of this melting point difference may further be 30°C, 40°C, 50°C, or 60°C. The upper limit of the difference in melting points between EVOH(Aa) and EVOH(Ab) may be, for example, 100°C, but 90°C is preferred, and 80°C, 70°C, 60°C, 50°C, 40°C, or 30°C may be more preferred. By setting the above melting point difference to or above the above lower limit, the moldability, heat stretchability, etc. of the resin composition can be improved. Conversely, by keeping the above melting point difference below the above upper limit, the gas barrier properties and the effect of suppressing flow marks during long-run (long-term continuous operation) of the resin composition can be enhanced.

[0036] The lower limit of the melting point of EVOH(Aa) is preferably 150°C, more preferably 160°C, and even more preferably 170°C. On the other hand, the upper limit of the melting point is preferably 220°C, more preferably 210°C, and even more preferably 200°C. When the melting point of EVOH(Aa) is within the above range, melt moldability is improved, and neck-in and die build-up during melt molding tend to be further suppressed.

[0037] The lower limit of the ethylene unit content of EVOH(Aa) is preferably 20 mol%, more preferably 23 mol%, and even more preferably 25 mol%. On the other hand, the upper limit of the ethylene unit content of EVOH(Aa) is preferably 50 mol%, more preferably 47 mol%, and even more preferably 43 mol%, 40 mol%, or 35 mol%. By setting the ethylene unit content of EVOH(Aa) to be above the lower limit, the effects of the resin composition, such as thermoformability and flexibility, are fully realized. On the other hand, by setting the ethylene unit content of EVOH(Aa) to be below the upper limit, the gas barrier properties of the resin composition can be enhanced.

[0038] The degree of saponification of EVOH(Aa) is preferably 90 mol% or higher, more preferably 95 mol% or higher, and even more preferably 99 mol% or higher. When the degree of saponification of EVOH(Aa) is 90 mol% or higher, the gas barrier properties, thermal stability, moisture resistance, etc., of the resin composition and the film obtained from the resin composition tend to be good. Furthermore, the degree of saponification of EVOH(Aa) may be 100 mol% or less, 99.97 mol% or less, or 99.94 mol% or less.

[0039] The lower limit of the melting point of EVOH(Ab) is preferably 90°C, more preferably 100°C, and even more preferably 110°C, 120°C, 130°C, 140°C, or 150°C. On the other hand, the upper limit of the melting point is preferably 220°C, more preferably 210°C, even more preferably 200°C, and even more preferably 190°C, 180°C, or 170°C. When the melting point of EVOH(Ab) is within the above range, melt moldability is improved, and neck-in and die build-up during melt molding tend to be further suppressed.

[0040] The lower limit of the ethylene unit content of EVOH(Ab) is preferably 30 mol%, more preferably 34 mol%, and even more preferably 38 mol%. On the other hand, the upper limit of the ethylene unit content of EVOH(Ab) is preferably 60 mol%, more preferably 55 mol%, and even more preferably 52 mol%. By setting the ethylene unit content of EVOH(Ab) to be above the lower limit, the moldability, flexibility, and other effects of the resin composition are fully realized. On the other hand, by setting the ethylene unit content of EVOH(Ab) to be below the upper limit, the gas barrier properties of the resin composition can be enhanced.

[0041] The preferred degree of saponification for EVOH(Ab) can be the same as that for EVOH(Aa).

[0042] The lower limit of the difference in ethylene unit content between EVOH(Ab) and EVOH(Aa) (Ab-Aa), that is, the value obtained by subtracting the ethylene unit content of EVOH(Aa) from the ethylene unit content of EVOH(Ab), is preferably 4.5 mol%, more preferably 8 mol%, even more preferably 12 mol%, and even more preferably 15 mol%. The upper limit of the above difference in ethylene unit content (Ab-Aa) is preferably 40 mol%, more preferably 30 mol%, and even more preferably 20 mol%. By setting the difference in ethylene unit content between EVOH(Ab) and EVOH(Aa) to be above the lower limit, the moldability, heat stretchability, etc., of the resin composition can be improved. Conversely, by setting the difference in ethylene unit content to be below the upper limit, the gas barrier properties of the resin composition can be further improved.

[0043] The lower limit of the mass ratio (Aa / Ab) between EVOH(Aa) and EVOH(Ab), that is, the mass ratio of the EVOH(Aa) content to the EVOH(Ab) content, is preferably 60 / 40, more preferably 62 / 38, and may be even more preferably 65 / 35, 68 / 32, 70 / 30, or 75 / 25. The upper limit of the mass ratio is preferably 95 / 5, more preferably 93 / 7, even more preferably 92 / 8, even more preferably 91 / 9, and may be even more still preferably 85 / 15. When the mass ratio is within the above range, the thermoformability, flexibility, etc. of the resin composition are excellent while maintaining gas barrier properties against various gases. For example, by setting the mass ratio (Aa / Ab) above the lower limit, the gas barrier properties and oil resistance of the resin composition can be improved. On the other hand, by setting the mass ratio (Aa / Ab) below the upper limit, the moldability, flexibility, etc. of the resin composition can be improved.

[0044] From the viewpoint of improving the moldability and flexibility of the resin composition, it is preferable that EVOH(Ab) has at least one structural unit (x) selected from the group consisting of the structural unit represented by formula (I), the structural unit represented by formula (II), and the structural unit represented by formula (III).

[0045] The lower limit of the content of structural unit (x) relative to the total vinyl alcohol structural units of EVOH(Ab) is preferably 0.3 mol%, more preferably 1 mol%, and even more preferably 3 mol%. By setting the content of structural unit (x) to above the above lower limit, the moldability, flexibility, etc., of the resin composition can be sufficiently improved. On the other hand, the upper limit of this content is preferably 40 mol%, more preferably 30 mol%, and even more preferably 20 mol%. By setting the content of structural unit (x) to below the above upper limit, gas barrier properties, etc., can be improved.

[0046] The EVOH(A) content in the resin composition of the present invention is preferably 70% by mass or more, more preferably 80% by mass or more, particularly preferably 90% by mass or more, and may also be 95% by mass or more, 99% by mass or more, or 99.9% by mass or more, from the viewpoint of gas barrier properties and the like. The resin constituting the resin composition of the present invention may be substantially composed of EVOH(A) alone. On the other hand, the EVOH(A) content in the resin composition of the present invention may be, for example, 99.9% by mass or less, or 99% by mass or less.

[0047] (Unsaturated aliphatic aldehyde (B)) The resin composition of the present invention comprises crotonaldehyde (B1) and further comprises at least one selected from the group consisting of 2,4-hexadienal (B2) and 2,4,6-octatrienal (B3).

[0048] The lower limit of the content b1 of crotonaldehyde (B1) relative to EVOH (A) in the resin composition of the present invention is preferably 0.01 ppm, more preferably 0.20 ppm, even more preferably 0.40 ppm, and may be even more preferably 0.70 ppm or 1.20 ppm. On the other hand, the upper limit of the content b1 is preferably 4.0 ppm, more preferably 3.5 ppm, even more preferably 2.7 ppm, and may be even more preferably 2.0 ppm or 1.5 ppm. When the content b1 is within the above range, it becomes easier to adjust the values ​​of b1 / (b2+b3), b1+b2+b3, and b2+2b3, which will be described later, to a suitable range. In addition, when the content b1 is within the above range, discoloration tends to be suppressed.

[0049] In one embodiment, the resin composition of the present invention contains 2,4-hexadienal (B2) in a specific ratio to crotonaldehyde (B1), which tends to suppress dye buildup while exhibiting excellent neck-in resistance. The lower limit of the content b2 of 2,4-hexadienal (B2) relative to EVOH (A) in the resin composition of the present invention is preferably 0.005 ppm, more preferably 0.01 ppm, and even more preferably 0.02 ppm. On the other hand, the upper limit of the content b2 is preferably 0.65 ppm, more preferably 0.20 ppm, even more preferably 0.10 ppm, even more preferably 0.08 ppm, and particularly preferably 0.06 ppm. When the content b2 is within the above range, it becomes easier to adjust the values ​​of b1 / (b2+b3), b1+b2+b3, and b2+2b3, which will be described later, to a suitable range. In addition, when the content b2 is within the above range, discoloration tends to be suppressed.

[0050] In one embodiment, the resin composition of the present invention tends to have excellent neck-in resistance while suppressing die buildup by containing 2,4,6-octatrienal (B3) in a specific ratio to crotonaldehyde (B1). Compared to 2,4-hexadienal (B2), 2,4-octatrienal (B3) has a greater effect on die buildup with respect to the amount added. Therefore, from the viewpoint of suppressing die buildup and improving neck-in resistance, the resin composition of the present invention preferably contains 2,4-hexadienal (B2) rather than 2,4,6-octatrienal (B3). The upper limit of the content b3 of 2,4,6-octatrienal (B3) relative to EVOH (A) in the resin composition of the present invention is preferably 0.325 ppm, more preferably 0.23 ppm, even more preferably 0.07 ppm, and particularly preferably 0.04 ppm. The lower limit of the content B3 may be 0 ppm or 0.005 ppm. When the content b3 is within the above range, it becomes easier to adjust the values ​​of b1 / (b2+b3), b1+b2+b3, and b2+2b3, which will be described later, to a suitable range. In addition, when the content b3 is within the above range, discoloration tends to be suppressed.

[0051] In the resin composition of the present invention, the ratio of the total content of 2,4-hexadienal (B2) b2 (ppm) and 2,4,6-octatrienal (B3) b3 (ppm) to the content of crotonaldehyde (B1) b1 (ppm) (b1 / (b2+b3)) is 2.0 or more and less than 150.0, resulting in excellent neck-in resistance. This neck-in resistance is an effect not seen when any of the unsaturated aliphatic aldehyde (B) compounds are used alone, and is only achieved when b1 / (b2+b3) falls within a specific range. The lower limit of b1 / (b2+b3) is preferably 4.0, more preferably 8.0. On the other hand, the upper limit of b1 / (b2+b3) is preferably 60.0, more preferably 25.0, and even more preferably 13.0. By keeping b1 / (b2+b3) within the above range, neck-in can be suppressed more effectively. As a result, the uniformity of the gas barrier properties can be improved by increasing the uniformity of the thickness of the resulting film layers.

[0052] In the resin composition of the present invention, the upper limit of the sum of the content of 2,4-hexadienal (B2) b2 (ppm) and twice the content of 2,4,6-octatrienal (B3) b3 (ppm) (b2 + 2b3) is 0.65 ppm or less, preferably 0.50 ppm, more preferably 0.30 ppm, and even more preferably 0.10 ppm. If b2 + 2b3 exceeds the above upper limit, the occurrence of die buildup cannot be suppressed. When die buildup occurs, the resulting film, etc., will have streaks and the like due to the die buildup, causing a decrease in gas barrier properties, appearance, adhesion of the inorganic vapor deposition layer, etc. b2 + 2b3 may be 0.005 ppm or more, or 0.01 ppm or more.

[0053] In the resin composition of the present invention, the upper limit of the total content (b1+b2+b3) of crotonaldehyde (B1), 2,4-hexadienal (B2), and 2,4,6-octatrienal (B3) relative to EVOH (A) is preferably 7.0 ppm, more preferably 4.0 ppm, even more preferably 3.5 ppm, even more preferably 3.0 ppm, even more preferably 1.5 ppm, and in some cases particularly preferably 1.0 ppm. By keeping b1+b2+b3 below the above upper limit, the discoloration of the resin composition can be sufficiently suppressed. On the other hand, the lower limit of b1+b2+b3 is preferably 0.01 ppm, more preferably 0.10 ppm, and in some cases even more preferably 0.30 ppm or 0.50 ppm.

[0054] (Inorganic particles (D)) The resin composition of the present invention, by having inorganic particles (D), can suppress vapor deposition defects and improve adhesion strength with the inorganic vapor deposition layer when forming an inorganic vapor deposition layer on the surface of a film containing a layer formed from the resin composition. Furthermore, the film containing a layer formed from the resin composition tends to have good break resistance, etc. Here, inorganic particles refer to particles whose main component is inorganic. The main component refers to the component with the highest content, for example, a component with a content of 50% by mass or more.

[0055] The inorganic material constituting the inorganic particles (D) is preferably an inorganic material containing at least one element selected from the group consisting of silicon, aluminum, magnesium, zirconium, cerium, tungsten, and molybdenum. Among these, an inorganic material containing at least one element selected from the group consisting of silicon, aluminum, and magnesium is more preferred because it is readily available. Examples of the above inorganic material include oxides, nitrides, and oxidized nitrides of the exemplified elements, with oxides being preferred. The inorganic particles (D) may contain one or more particles of different types. Furthermore, each particle may be formed from one or more inorganic materials.

[0056] The lower limit of the average particle diameter of the inorganic particles (D) is preferably 0.5 μm, more preferably 1.5 μm, and even more preferably 2.0 μm. The upper limit of the average particle diameter of the inorganic particles (D) is preferably 10 μm, more preferably 8 μm, and even more preferably 5 μm. When the average particle diameter of the inorganic particles (D) is within the above range, the break resistance, vapor deposition defect suppression, and adhesion strength of the inorganic vapor deposition layer of the resulting film can be improved. In particular, when the average particle diameter of the inorganic particles (D) is above the lower limit, the adhesion strength of the inorganic vapor deposition layer tends to increase.

[0057] The lower limit of the inorganic particle (D) content d relative to EVOH(A) is 50 ppm, preferably 100 ppm, and more preferably 150 ppm. The upper limit of the inorganic particle (D) content d is 5000 ppm, preferably 4000 ppm, more preferably 3000 ppm, and in some cases even more preferably 2000 ppm or 1000 ppm. When the inorganic particle (D) content d is within the above range, the break resistance, vapor deposition defect suppression, and adhesion strength of the inorganic vapor deposition layer of the resulting film can be improved. In particular, when the inorganic particle (D) content d is above the lower limit, the adhesion strength of the inorganic vapor deposition layer tends to increase.

[0058] (Conjugated polyene compound (C)) The resin composition of the present invention preferably further contains a conjugated polyene compound (C). The conjugated polyene compound (C) can suppress the deterioration of color tone due to oxidative degradation of EVOH (A) during melt molding. Here, the conjugated polyene compound (C) is a compound having a structure in which carbon-carbon double bonds and carbon-carbon single bonds are alternately linked, and the number of carbon-carbon double bonds is two or more, in other words, a compound having a conjugated double bond. However, 2,4-hexadienal (B2) and 2,4,6-octatrienal (B3) are not considered to be conjugated polyene compounds (C). The conjugated polyene compound (C) may be a conjugated diene having two conjugated double bonds, a conjugated triene having three conjugated double bonds, or a conjugated polyene having more than that number. Furthermore, there may be multiple sets of conjugated double bond structures in one molecule. For example, compounds that have three conjugated triene structures in the same molecule, such as tung oil, are also included in the conjugated polyene compound (C). A preferred upper limit for the number of conjugated double bonds in the conjugated polyene compound (C) is seven. If the resin composition contains a conjugated polyene compound (C) having eight or more conjugated double bonds, the likelihood of discoloration of the pellets and, consequently, the molded article increases.

[0059] In addition to the conjugated double bond, the conjugated polyene compound (C) may have other functional groups such as carboxyl groups and their salts, hydroxyl groups, ester groups, ether groups, amino groups, imino groups, amide groups, cyano groups, diazo groups, nitro groups, sulfone groups and their salts, sulfonyl groups, sulfoxide groups, sulfide groups, thiol groups, phosphate groups and their salts, phenyl groups, halogen atoms, double bonds, triple bonds, etc.

[0060] The lower limit of the number of carbon atoms in the conjugated polyene compound (C) is preferably 4. The upper limit of the number of carbon atoms in the conjugated polyene compound (C) is preferably 30, and more preferably 10.

[0061] Examples of conjugated polyene compounds (C) include isoprene, 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-t-butyl-1,3-butadiene, 1,3-pentadiene, 2,3-dimethyl-1,3-pentadiene, 2,4-dimethyl-1,3-pentadiene, 3,4-dimethyl-1,3-pentadiene, and 3-ethyl-1,3-pentadie. 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene, 1,3-hexadiene, 2,4-hexadiene, 2,5-dimethyl-2,4-hexadiene, 1,3-octadiene, 1,3-cyclopentadiene, 1,3-cyclohexadiene, 1-phenyl-1,3-butadiene, 1,4-diphenyl-1,3-butadiene Examples include conjugated diene compounds such as ene, 1-methoxy-1,3-butadiene, 2-methoxy-1,3-butadiene, 1-ethoxy-1,3-butadiene, 2-ethoxy-1,3-butadiene, 2-nitro-1,3-butadiene, chloroprene, 1-chloro-1,3-butadiene, 1-bromo-1,3-butadiene, 2-bromo-1,3-butadiene, ocimene, phellandrene, myrcene, farnesene, sorbic acid, sorbate esters, and sorbates; conjugated triene compounds such as 1,3,5-hexatriene, 2,4,6-octatriene-1-carboxylic acid, eleostearic acid, tung oil, cholecalciferol, flubene, and tropone; and cyclooctatetraene, 2,4,6,8-decatetraene-1-carboxylic acid, retinol, and retinoic acid.

[0062] The conjugated polyene compound (C) is preferably sorbic acid, sorbate ester, sorbate salt, myrcene, or a mixture of two or more of these, and more preferably sorbic acid, sorbate salt (sodium sorbate, potassium sorbate, etc.), or a mixture thereof. Sorbic acid, sorbate salt, or a mixture thereof is preferred from the viewpoint of hygiene and availability because it has a high effect in suppressing oxidative degradation at high temperatures and is also widely used industrially as a food additive.

[0063] The molecular weight of the conjugated polyene compound (C) is usually 1,000 or less, preferably 500 or less, and more preferably 300 or less. When the molecular weight of the conjugated polyene compound (C) is below the above upper limit, the dispersion state of the conjugated polyene compound (C) in the resin composition becomes good, and the appearance after melt molding tends to improve. The lower limit of the molecular weight of the conjugated polyene compound (C) is, for example, 54, but it may also be 60 or 80.

[0064] The lower limit of the content c of the conjugated polyene compound (C) relative to EVOH(A) in the resin composition of the present invention is preferably 1 ppm, more preferably 3 ppm. Furthermore, the content c of the conjugated polyene compound (C) relative to EVOH(A) in the resin composition of the present invention is preferably less than 300 ppm, more preferably 100 ppm or less, even more preferably 70 ppm or less, even more preferably 30 ppm or less, and particularly preferably 20 ppm or less, or 10 ppm or less. When the content c of the conjugated polyene compound (C) is within the above range, the deterioration of hue during melt molding tends to be further suppressed.

[0065] (Other optional components) The resin composition of the present invention may contain, as other optional components besides EVOH(A), unsaturated aliphatic aldehyde (B), inorganic particles (D), and conjugated polyene compounds (C), boron compounds, carboxylic acids, phosphorus compounds, metal ions, antioxidants, ultraviolet absorbers, plasticizers, antistatic agents, lubricants, colorants, fillers, heat stabilizers, other resins other than EVOH(A), metal salts of higher aliphatic carboxylic acids, etc. The resin composition of the present invention may contain two or more of these components. If the resin composition of the present invention contains other optional components, the upper limit of their total content is preferably 1% by mass, and may also be preferably 0.5% by mass.

[0066] Boron compounds suppress gelation during melt molding and also suppress torque fluctuations (viscosity changes during heating) in extrusion molding machines, etc. Examples of the above boron compounds include boric acids such as orthoboric acid, metaboric acid, and tetraboric acid; boric acid esters such as triethyl borate and trimethyl borate; alkali metal salts or alkaline earth metal salts of the above boric acids, borates such as borax; and boron hydrides. Among these, boric acids are preferred, and orthoboric acid (hereinafter also referred to as "boric acid") is more preferred. The lower limit of the content of the boron compound relative to EVOH(A) is preferably 100 ppm, and more preferably 500 ppm. Furthermore, the upper limit of the content of the boron compound relative to EVOH(A) is preferably 5,000 ppm, more preferably 3,000 ppm, and even more preferably 1,000 ppm. By setting the content of the boron compound to be above the above lower limit, torque fluctuations in extrusion molding machines, etc. can be sufficiently suppressed. On the other hand, by keeping the boron compound content below the above upper limit, gelation during melt molding becomes less likely, improving the appearance of the resin composition and, consequently, the molded product. Note that the boron compound content is expressed as the orthoboric acid equivalent of the boron compound.

[0067] Carboxylic acids prevent discoloration of the resin composition and, consequently, 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 their salts. Preferred carboxylic acids are those with four or fewer carbon atoms or saturated carboxylic acids, with acetic acid being more preferred. These acetic acids include acetic acid and acetate salts. It is preferable to use acetic acid and acetate salts in combination, and more preferable to use acetic acid and sodium acetate in combination. The lower limit of the carboxylic acid content relative to EVOH(A) is preferably 50 ppm, more preferably 100 ppm, and even more preferably 150 ppm. The upper limit of the carboxylic acid content relative to EVOH(A) is preferably 1,000 ppm, more preferably 500 ppm, and even more preferably 400 ppm. By setting the carboxylic acid content above the above lower limit, a sufficient discoloration suppression effect can be obtained, and the occurrence of yellowing can be sufficiently suppressed. On the other hand, by keeping the carboxylic acid content below the above upper limit, gelation is less likely to occur during melt molding, especially during long melt molding periods, resulting in a better appearance for molded products.

[0068] Phosphorus compounds suppress the occurrence of defects such as streaks and fish eyes, as well as discoloration, and improve long-run performance. Examples of phosphorus compounds include phosphates such as phosphoric acid and phosphorous acid. The phosphate may be in the form of monophosphate, diphosphate, or tertiary phosphate. The cation species of the phosphate is not particularly limited, but alkali metal salts and alkaline earth metal salts are preferred, of which 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. The lower limit of the phosphorus compound content relative to EVOH(A) is preferably 1 ppm, more preferably 10 ppm, even more preferably 20 ppm, and particularly preferably 30 ppm. The upper limit of the phosphorus compound content relative to EVOH(A) is preferably 200 ppm, more preferably 150 ppm, and even more preferably 100 ppm. By setting the phosphorus compound content above the lower limit or below the upper limit, thermal stability is improved, and the formation of gel-like particles and discoloration during long-term melt molding becomes less likely.

[0069] Examples of metal ions include monovalent metal ions, divalent metal ions, and other transition metal ions, which may consist of one or more types. Among these, monovalent metal ions and divalent metal ions are preferred. Among monovalent metal ions, alkali metal ions are preferred, such as lithium, sodium, potassium, rubidium, and cesium ions, with sodium or potassium ions being preferred from the viewpoint of industrial availability. 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 from the viewpoint of availability, and specifically, sodium acetate, potassium acetate, sodium phosphate, and potassium phosphate are preferred. It is also preferable to include divalent metal ions as metal ions. When the metal ions include divalent metal ions, for example, the thermal degradation of EVOH when trim is recovered and reused may be suppressed, and the generation of gel and blemishes in the resulting molded article may be suppressed. Examples of divalent metal ions include beryllium, magnesium, calcium, strontium, barium, and zinc ions, but 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. Preferred carboxylic acids constituting the carboxylates are carboxylic acids having 1 to 30 carbon atoms, specifically including acetic acid, propionic acid, butyric acid, stearic acid, lauric acid, montanic acid, behenic acid, octic acid, sebacic acid, ricinoleic acid, myristic acid, palmitic acid, etc., with acetic acid and stearic acid being preferred among them. The lower limit of the metal ion content in EVOH(A) is preferably 1 ppm, more preferably 100 ppm, and even more preferably 150 ppm. On the other hand, the upper limit of the metal ion content is preferably 1,000 ppm, more preferably 400 ppm, and even more preferably 350 ppm. When the metal ion content relative to EVOH(A) is 1 ppm or higher, the resulting multilayer structure tends to exhibit good interlayer adhesion.On the other hand, when the metal ion content is 1,000 ppm or less, the stain resistance tends to be good.

[0070] 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), and octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate. Examples of ultraviolet absorbers include ethylene-2-cyano-3,3'-diphenyl acrylate, 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, and 2-hydroxy-4-oxybenzophenone.

[0071] Examples of plasticizers include dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, and phosphate esters. Examples of antistatic agents include pentaerythritol monostearate, sorbitan monopalmitate, sulfated polyolefins, polyethylene oxide, and polyethylene glycol (trade name: Carbowax).

[0072] Examples of lubricants include ethylene bisstearamide and butyl stearate. Examples of colorants include carbon black, phthalocyanine, quinacridone, indoline, azo pigments, and red iron oxide. Examples of fillers include glass fiber, wollastonite, calcium silicate, talc, and montmorillonite. Examples of heat stabilizers include hindered phenol compounds and hindered amine compounds.

[0073] Other resins besides EVOH(A) include, for example, polyamides and polyolefins. Examples of metal salts of higher aliphatic carboxylic acids include, for example, sodium stearate, potassium stearate, calcium stearate, and magnesium stearate.

[0074] In the resin composition of the present invention, the total content of EVOH (A), unsaturated aliphatic aldehyde (B) (crotonaldehyde (B1), 2,4-hexadienal (B2), and 2,4,6-octatrienal (B3)), and inorganic particles (D) 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 consist substantially only of EVOH (A), unsaturated aliphatic aldehyde (B), and inorganic particles (D), or the resin composition of the present invention may consist solely of EVOH (A), unsaturated aliphatic aldehyde (B), and inorganic particles (D). In this specification, "substantially consisting only of" means that the inclusion of optional components is permitted as long as it does not affect the effects of the present invention, and in this specification, "consisting only of" means that optional components other than impurities that are inevitably included are excluded.

[0075] The lower limit of the melt flow rate (MFR) of the resin composition of the present invention at 210°C and under a load of 2,160 g is preferably 0.5 g / 10 min, and more preferably 1 g / 10 min. On the other hand, the upper limit of the MFR is preferably 30 g / 10 min, and more preferably 20 g / 10 min. By having the MFR of the resin composition of the present invention within the above range, melt moldability and other properties can be improved. Furthermore, when the MFR of the resin composition of the present invention is within the above range, the neck-in resistance tends to be better.

[0076] <Method for preparing resin compositions> The method for producing the resin composition of the present invention is not particularly limited as long as it allows for the blending of an unsaturated aliphatic aldehyde (B) and inorganic particles (D) into EVOH (A). For example, the production method is: (1) A step of copolymerizing ethylene and vinyl ester, and (2) A step of saponifying the copolymer obtained in step (1). A method for producing a resin composition comprising the above, characterized in that the resin composition contains a predetermined amount and a predetermined ratio of unsaturated aliphatic aldehyde (B) and inorganic particles (D).

[0077] There are no particular limitations on the method for incorporating unsaturated aliphatic aldehyde (B) into the resin composition. Examples include adding unsaturated aliphatic aldehyde (B) in step (1), adding unsaturated aliphatic aldehyde (B) in step (2), or adding unsaturated aliphatic aldehyde (B) to EVOH (A) obtained in step (2). When adopting the method of adding unsaturated aliphatic aldehyde (B) in step (1) or step (2), it is necessary to increase the amount added, taking into account the amount consumed in the polymerization reaction in step (1) and the saponification reaction in step (2), in order to contain the desired amount of unsaturated aliphatic aldehyde (B) in the resulting resin composition. Therefore, when adding unsaturated aliphatic aldehyde (B) in the polymerization or saponification reaction steps, it is preferable to add the amount of unsaturated aliphatic aldehyde (B) that will be consumed. On the other hand, the method of adding an unsaturated aliphatic aldehyde (B) to EVOH (A) obtained from step (2) above is superior in terms of operability because it can be added without considering consumption within the process.

[0078] Methods for adding unsaturated aliphatic aldehyde (B) to EVOH(A) include, for example, a method of pre-mixing unsaturated aliphatic aldehyde (B) with EVOH(A) and granulating pellets; a method of impregnating strands precipitated in a paste precipitation process after saponification of ethylene-vinyl ester copolymer with unsaturated aliphatic aldehyde (B); a method of impregnating strands after cutting with unsaturated aliphatic aldehyde (B); a method of adding unsaturated aliphatic aldehyde (B) to remelted chips of a dried resin composition; a method of melt-kneading a blend of each component of EVOH(A) and unsaturated aliphatic aldehyde (B); a method of feeding unsaturated aliphatic aldehyde (B) into the EVOH(A) molten material from the middle of the extruder to incorporate it; and a method of creating a masterbatch by granulating a portion of EVOH(A) with unsaturated aliphatic aldehyde (B) at a high concentration, and then dry-blending and melt-kneading it with EVOH(A).

[0079] Of these methods, a method of granulating pellets by pre-mixing unsaturated aliphatic aldehyde (B) with EVOH(A) is preferred, from the viewpoint of being able to uniformly disperse a trace amount of unsaturated aliphatic aldehyde (B) in EVOH(A). Specifically, a resin composition pellet in which unsaturated aliphatic aldehyde (B) is uniformly mixed with EVOH(A) can be obtained by adding unsaturated aliphatic aldehyde (B) to a solution obtained by dissolving EVOH(A) in a good solvent such as a water / methanol mixed solvent, extruding the mixed solution into a poor solvent through a nozzle or the like to precipitate and / or solidify it, and then washing and / or drying it.

[0080] Methods for incorporating inorganic particles (D) and other components in addition to unsaturated aliphatic aldehydes (B) into EVOH (A) include, for example, a method of melt-kneading the pellets together with the inorganic particles (D), a method of mixing the inorganic particles (D) together with the unsaturated aliphatic aldehydes (B) when preparing the pellets, and a method of dry-blending the inorganic particles (D) into the pellets. Ribbon blenders, high-speed mixer kneaders, mixing rolls, extruders, intensive mixers, etc., can be used for mixing the inorganic particles (D).

[0081] The resin composition of the present invention is preferably in pellet form for ease of handling. The shape of the pellets of the resin composition of the present invention is not particularly limited, but examples include cylindrical, prismatic, spherical, and lenticular. Among these, cylindrical, spherical, or lenticular pellets are preferred from the viewpoint of pellet transport stability, handling, and productivity. In the case of cylindrical pellets, the diameter is preferably 1 mm to 10 mm, more preferably 2 mm to 8 mm, and the height is preferably 1 mm to 10 mm, more preferably 2 mm to 8 mm, and even more preferably 3 mm to 5 mm. In the case of spherical or lenticular pellets, the length in the short direction is preferably 1 mm to 10 mm, more preferably 2 mm to 8 mm, and the length in the long direction is preferably 1 mm to 10 mm, more preferably 2 mm to 8 mm.

[0082] <Molded body> The resin composition of the present invention can be formed into molded articles such as films, sheets, tubes, bags, and bottles by melt molding or the like. Molded articles having a portion made of the resin composition of the present invention can suppress neck-in and die build-up, thus the molded articles of the present invention have high productivity. The molded article only needs to have a portion formed from the resin composition of the present invention. That is, the molded article may be made only from the resin composition of the present invention, or it may be made from a portion made only from the resin composition of the present invention and other portions. Examples of melt molding methods include extrusion molding, cast molding, inflation extrusion molding, blow molding, melt spinning, injection molding, injection blow molding, and co-extrusion blow molding. The melt molding temperature varies depending on the melting point of EVOH(A), but is preferably around 150 to 270°C. These molded articles can also be crushed and remolded for reuse. Furthermore, films, sheets, etc. can be uniaxially or biaxially stretched.

[0083] <Single-layer film> The single-layer film of the present invention is a single-layer film made from the resin composition of the present invention. That is, the single-layer film is a film consisting only of a layer formed from the resin composition of the present invention. Because the single-layer film of the present invention is formed from a resin composition that suppresses neck-in and die build-up during melt molding, it exhibits excellent continuous production properties and high uniformity of gas barrier properties. Furthermore, the single-layer film has high adhesion to inorganic vapor-deposited layers and is suitable as a base film for vapor-deposited films. The average thickness of the single-layer film of the present invention is preferably, for example, 1 μm or more and less than 300 μm, and more preferably 5 μm or more and less than 100 μm. The single-layer film of the present invention can be suitably used as various packaging materials and the like.

[0084] The single-layer film of the present invention may be an unstretched film, but it is preferably stretched, and more preferably biaxially stretched. That is, the single-layer film is preferably a stretched film, and more preferably a biaxially stretched film. Stretching tends to improve gas barrier properties and strength. Furthermore, if the single-layer film of the present invention is a stretched film, the possibility of breakage is low, resulting in good productivity.

[0085] (Method of manufacturing a single-layer film) The single-layer film of the present invention can be manufactured by known methods. The method for forming the single-layer film is not particularly limited and includes, for example, melting, solution, and calendering methods, with melting being preferred. Examples of melting methods include the T-die method (casting method) and inflation method, with casting being preferred. In particular, it is preferable to manufacture the single-layer film of the present invention by a method comprising a casting molding step of melt-extruding the resin composition constituting the single-layer film onto a casting roll, and a step of stretching the unstretched single-layer film obtained from the resin composition. The melting temperature in the melting method varies depending on the melting point of the resin composition, but is preferably around 150 to 300°C.

[0086] The stretching can be uniaxial or biaxial, with biaxial stretching being preferred. Biaxial stretching can be sequential or simultaneous. The lower limit of the stretching ratio in terms of area is preferably 6 times, and more preferably 8 times. The upper limit of the stretching ratio is preferably 15 times, and more preferably 12 times. When the stretching ratio is within the above range, the uniformity of the thickness, gas barrier properties, and mechanical strength of the single-layer film can be improved. The stretching temperature can be, for example, 60°C to 120°C.

[0087] In manufacturing the single-layer film of the present invention, a step of heat-treating the stretched single-layer film may be included after the stretching step. The heat treatment temperature is usually set higher than the stretching temperature, and can be, for example, between 120°C and 200°C.

[0088] The single-layer film of the present invention is suitably used as a material for various packaging containers, such as food packaging containers, pharmaceutical packaging containers, industrial chemical packaging containers, and agricultural chemical packaging containers.

[0089] <Laminate> The laminate of the present invention is a laminate having a single-layer film of the present invention and other layers. The laminate has advantages over a single-layer film, such as improved functionality. Furthermore, since the laminate of the present invention is manufactured using a resin composition that suppresses neck-in and die build-up, it has excellent continuous production properties, high gas barrier properties and uniformity, and good appearance and adhesion to other layers (such as inorganic vapor-deposited layers). The laminate may also be a multilayer film. The lower limit of the number of layers in the laminate may be two or three. The upper limit of the number of layers in the laminate may be 1000, 100, 10, 5, 3, or 2.

[0090] Other layers include thermoplastic resin layers formed from thermoplastic resins, adhesive resin layers formed from adhesive resins, inorganic vapor-deposited layers, paper layers, metal layers, and the like. The other layers may consist of one or more types of layers.

[0091] 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 (α-olefin with 4 to 20 carbon atoms) copolymer, polybutene, polypentene, and other olefins alone or copolymers thereof; 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, and chlorinated polypropylene. Among these, polypropylene, polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyamide, polystyrene, and polyester are preferred.

[0092] The adhesive resin is not particularly limited as long as it has adhesion to the gas barrier layer and the layers made 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 obtained by chemically bonding an ethylenically unsaturated carboxylic acid, its ester, or its anhydride to an olefin polymer is preferred. Here, 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.

[0093] The layer configuration of the laminate can be such that, if we define the layers as follows: x is a layer made of a resin other than the resin composition of the present invention, y is a single-layer film of the present invention (a layer made of the resin composition of the present invention), z is an adhesive resin layer, and " / " means an adhesive layer or direct lamination, then examples include x / y, x / y / x, x / z / y, x / z / y / z / x, x / y / x / y / x, x / z / y / z / x / z / y / z / x, etc. If multiple x, y, and z layers are provided, their types may be the same or different.

[0094] As a method for manufacturing the laminate of the present invention, when the other layers are thermoplastic resin layers, adhesive resin layers, etc., it can be manufactured by, for example, melt-extruding the other components onto the single-layer film of the present invention, laminating the single-layer film of the present invention and the other layers using known adhesives such as organic titanium compounds, isocyanate compounds, and polyester compounds, or co-extruding the resin composition of the present invention with the other components.

[0095] <Metal-deposited film> In the laminate of the present invention, one preferred embodiment is that the other layers are inorganic vapor-deposited layers. Such vapor-deposited films will be described below.

[0096] The vapor-deposited film comprises a single-layer film of the present invention and an inorganic vapor-deposited layer, which is another layer. Since the vapor-deposited film is manufactured using a resin composition that suppresses neck-in and die build-up, it exhibits excellent continuous production capabilities, high gas barrier properties and uniformity, and good adhesion of the inorganic vapor-deposited layer. Furthermore, since the resin composition contains a predetermined amount of inorganic particles (D), a vapor-deposited film is obtained that is less prone to vapor deposition defects and has excellent adhesion strength of the inorganic vapor-deposited layer. The vapor-deposited film may further have other layers besides the single-layer film of the present invention (a layer made of the resin composition of the present invention) and the inorganic vapor-deposited layer. In the vapor-deposited film, the inorganic vapor-deposited layer is usually directly laminated on the single-layer film of the present invention.

[0097] Inorganic vapor-deposited layers typically consist mainly of inorganic materials such as metals and inorganic oxides. Preferably, the inorganic vapor-deposited layer is either a metal vapor-deposited layer mainly composed of aluminum, or an inorganic oxide vapor-deposited layer mainly composed of alumina or silica. While a metal vapor-deposited layer is preferred for light-shielding purposes, an inorganic oxide vapor-deposited layer is preferred from the viewpoint of visibility of the contents as a packaging material, microwave suitability, and the ability to suppress the generation of gels and lumps during melt molding of crushed materials.

[0098] The metal vapor deposition layer is generally a layer mainly composed of aluminum. The aluminum atom content in the metal vapor deposition layer is preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 90 mol% or more, and particularly preferably 95 mol% or more.

[0099] The inorganic oxide vapor-deposited layer may be an inorganic oxide, such as an oxide of silicon, aluminum, magnesium, calcium, potassium, tin, sodium, boron, titanium, lead, zirconium, or yttrium, preferably an alumina or silica vapor-deposited film.

[0100] The average thickness of the inorganic vapor-deposited layer is preferably 120 nm or less, more preferably 100 nm or less, even more preferably 80 nm or less, and in some cases even more preferably 60 nm or less. Furthermore, the average thickness of the inorganic vapor-deposited layer is preferably 10 nm or more, more preferably 15 nm or more, even more preferably 20 nm or more, and even more preferably 30 nm or more. The average thickness of the inorganic vapor-deposited layer is the average value of the thickness at any 10 points on the cross-section of the inorganic vapor-deposited layer measured by an electron microscope.

[0101] The inorganic vapor-deposited layer can be deposited by known physical or chemical vapor deposition methods. Specifically, examples include vacuum vapor deposition, sputtering, ion plating, ion beam mixing, plasma CVD, laser CVD, MO-CVD, and thermal CVD. However, physical vapor deposition is preferred, and vacuum vapor deposition is particularly preferred. The upper limit of the substrate surface temperature during deposition is preferably 60°C, more preferably 55°C, and even more preferably 50°C. The lower limit of the substrate surface temperature during deposition is not particularly limited, but is preferably 0°C, more preferably 10°C, and even more preferably 20°C. The substrate surface may be plasma-treated before deposition. Known methods can be used for this plasma treatment, and atmospheric pressure plasma treatment is preferred. In atmospheric pressure plasma treatment, nitrogen, helium, neon, argon, krypton, xenon, radon, etc., are used as the discharge gas. Among these, nitrogen, helium, and argon are preferred, and nitrogen is particularly preferred because it can reduce costs.

[0102] In the vapor-deposited film, the inorganic vapor-deposited layer may be covered by another layer. Furthermore, the vapor-deposited film may have multiple inorganic vapor-deposited layers.

[0103] The layer structure of the vapor-deposited film can be defined as follows: if the x-layer is made of a resin other than the resin composition of the present invention, the y-layer is the single-layer film of the present invention (the layer made of the resin composition of the present invention), the z-layer is the adhesive resin layer, and the v-layer is the inorganic vapor-deposited layer, then examples of the configurations include y / v, v / y / v, x / y / v, x / z / y / v, v / y / z / x / z / y / v, x / v / y / v, x / y / v / x, x / v / y / v / x, x / z / v / y / v / z / x, and so on.

[0104] Laminates of the present invention, such as vapor-deposited films, are particularly suitable for use in packaging materials that require excellent barrier properties. Specifically, examples include containers (bags, tubes, lids, etc.), food and beverage packaging materials, medical infusion bag materials, tire tube materials, inner bag materials for bag-in-boxes, cosmetic packaging materials, dental care packaging materials, pharmaceutical packaging materials, agricultural films (greenhouse films, soil fumigation films), grain storage bags, geomembranes, and vacuum insulation outer bags. [Examples]

[0105] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0106] [Evaluation Method] (1) Measurement of ethylene unit content, degree of saponification, and amount of epoxypropane modification (amount of modification relative to total vinyl alcohol units) The crude dried EVOH obtained in the synthesis example was dried in a vacuum dryer at 120°C for 12 hours. The vacuum-dried EVOH was dissolved in deuterated dimethyl sulfoxide (DMSO-d6) containing tetramethylsilane (TMS) as an internal standard and trifluoroacetic acid (TFA) as an additive, and heated at 500 MHz. 1 Measurements were taken at 80°C using 1H-NMR (GX-500, JEOL Ltd.), and the ethylene unit content and degree of saponification were determined from the peak intensity ratios of ethylene units, vinyl alcohol units, and vinyl ester units. When measuring the EVOH(A9) pellets obtained in Synthesis Example 9, measurements were performed without vacuum drying, and the amount of modification relative to the total vinyl alcohol units was simultaneously calculated from the peak intensity of the epoxypropane-modified vinyl alcohol units. In the EVOH(A9) obtained in Synthesis Example 9, the amount of epoxypropane modification relative to the total vinyl alcohol units is equal to the content of structural unit (x) relative to the total vinyl alcohol units.

[0107] (2) Sodium ion content, phosphoric acid content and boric acid content 0.5 g of the dried resin composition pellets obtained in the Reference Example, Reference Comparative Example, Example, and Comparative Example were placed in a Teflon® pressure vessel, and 5 mL of concentrated nitric acid was added to decompose it at room temperature for 30 minutes. After 30 minutes, the lid was closed, and the decomposition was carried out by heating at 150°C for 10 minutes, then at 180°C for 5 minutes, using a wet decomposition apparatus (Actac Co., Ltd. "MWS-2"), and then cooled to room temperature. This processed solution was transferred to a 50 mL volumetric flask (TPX®) and diluted with pure water. The metal content of this solution was analyzed using an ICP emission spectrometer (PerkinElmer "OPTIMA4300DV"), and the content of sodium ions (element sodium), phosphoric acid, and boric acid was measured. The phosphoric acid content was calculated as a phosphate root equivalent, and the boric acid content was calculated as an orthoboric acid equivalent. Calibration curves prepared using commercially available standard solutions were used for quantification.

[0108] (3) Acetic acid content 20 g of dried resin composition pellets obtained in the Reference Example, Reference Comparative Example, Example, and Comparative Example were placed in 100 mL of deionized water and heated at 95°C for 6 hours for extraction. The extract was neutralized and titrated with 1 / 50 N NaOH using phenolphthalein as an indicator to quantify the acetic acid content.

[0109] (4) Melt Flow Rate (MFR) The dried resin composition pellets obtained in the reference example and reference comparative example were filled into a 9.55 mm inner diameter, 162 mm long cylinder of a melt indexer L244 (manufactured by Takara Kogyo Co., Ltd.), melted at 210°C, and then a uniform load was applied to the molten resin composition using a plunger with a mass of 2,160 g and a diameter of 9.48 mm. The amount of resin composition extruded per unit time (g / 10 min) through a 2.1 mm diameter orifice located in the center of the cylinder was measured and defined as the MFR (Metal Flow Rate).

[0110] (5) Determination of crotonaldehyde, 2,4-hexadienal and 2,4,6-octatrienal Samples were prepared by freeze-pulverizing 0.50 g of dried resin composition pellets obtained in the Reference Example, Reference Comparative Example, Example, and Comparative Example, and weighing 50.0 mg of the resulting sample into a glass tube for a thermal desorption gas chromatograph mass spectrometer. Using the thermal desorption gas chromatograph mass spectrometer described below, the sample was heated under the conditions described below to adsorb the volatile gas from the sample into an adsorption tube. The gas re-released from the adsorption tube was then separated by a column, and the peaks for each component were detected. Calibration curves were created from the peak areas of standard samples of crotonaldehyde, 2,4-hexadienal, and 2,4,6-octatrienal, and each component was quantified using the absolute calibration curve method. When measuring the standard sample, the standard sample was impregnated into an adsorption tube (manufactured by Tenax® / Carboxen®), and the adsorption tube impregnated with the standard sample was used instead of the sample tube. The temperature at which the sample was released after adsorption was changed from the sample tube temperature of 170°C to the adsorption tube temperature of 260°C, but the measurement was performed in the same manner as when measuring the sample tube. (Heating desorption section) Device: TurboMatrix-ATD (manufactured by PerkinElmer Japan) Temperature when adsorbing the sample onto the adsorption tube: 170°C (sample tube), -30°C (adsorption tube), 250°C (valve), 260°C (transfer line) Adsorption time to the adsorption tube: 10 minutes Temperature during release after sample adsorption: 170°C (sample tube), 260°C (adsorption tube), 250°C (valve), 260°C (transfer line) Adsorption tube release time: 35 minutes Carrier gas: Helium Flow rate of carrier gas into the column: 1.0 ml / min Pressure: 120kPa (Gas Chromatography and Mass Spectrometry Department) Equipment: 7890B GC System, 7977B MSD (manufactured by Agilent Technologies) Column: DB-WAX UI (Length: 30m, Inner diameter: 0.25mm, Film thickness: 0.50μm) Column oven temperature: Hold at 40°C for 5 minutes, then raise the temperature to 240°C at a rate of 10°C / min, and hold for 10 minutes (total measurement time: 35 minutes). Transfer line (connection point) temperature: 240℃ Ionization conditions: EI+ Detection ion mass range: m / z = 29-600 Detection method: SCAN (Standard sample) Crotonaldehyde: Manufactured by Aldrich. 2,4-Hexadienal: Manufactured by Aldrich. 2,4,6-Octatrienal: Manufactured by Nerd Research Institute

[0111] (6) Determination of sorbic acid and myrcene The dried resin composition pellets obtained in the Reference Example, Reference Comparative Example, Example, and Comparative Example were freeze-dried and pulverized. 22 g of the pulverized material was loaded into a Soxhlet extractor and extracted with 100 mL of chloroform for 16 hours. The amounts of sorbic acid and myrcene in the resulting chloroform extract were quantitatively analyzed by high-performance liquid chromatography to determine the content of sorbic acid and myrcene in the resin composition. Calibration curves prepared using sorbic acid and myrcene standards were used for quantification.

[0112] (7) Dybuild-up evaluation The dried resin composition pellets obtained in the Reference Example, Reference Comparative Example, Example, and Comparative Example were extruded from an extruder under the following conditions. After 60 minutes, the die buildup (die lip) around the die was visually inspected and evaluated according to the following criteria. In cases A to D, it was determined that die buildup was suppressed. (Extruder conditions) • Equipment: 20mmφ single-screw extruder (D2020, manufactured by Toyo Seiki Seisakusho Co., Ltd.) L / D:20 • Screw: Full Flight Screen mesh: 50 mesh / 100 mesh / 50 mesh • Die: φ1mm, 1 hole ·Set temperature: C1 / C2 / C3 / D=180℃ / 220℃ / 220℃ / 220℃ ·Discharge amount: 1.44kg / h • Rotation speed: 100 rpm (Evaluation: Judgment Criteria) A (Good): No eye discharge. B (Fairly good): Very slight amount of eye discharge. C (Acceptable): A small amount of eye discharge is present. D (Slightly Poor): Clear eye discharge is present. E (Defective): Large particles of eye discharge are attached all around the die hole.

[0113] (8) Hue evaluation The Yellow Index (YI) values ​​of the dried resin composition pellets obtained in the Reference Example, Reference Comparative Example, Example, and Comparative Example were measured and calculated using a Hunter LAB Scan XE in accordance with JIS K7373:2006. A smaller value indicates suppressed yellowing and superior hue.

[0114] (9) Evaluation of neck-in resistance during film formation Using the dried resin composition pellets obtained in the Reference Example, Reference Comparative Example, Example, and Comparative Example, the resin composition was extruded from a single-screw extruder under the following conditions. The width of the molten resin (melt curtain) discharged from the T-die 10 minutes after feeding the dried resin composition pellets was measured at a position 100 mm from the lip (T-die discharge port). The width of the molten resin was evaluated according to the following criteria. In cases A to C, it was determined that neck-in was suppressed. (Extruder conditions) • Extruder: L / D=26, 40mmφ single-screw extruder • Screw: Full Flight • Screw rotation speed: 50 rpm Screen mesh: 50 mesh / 100 mesh / 50 mesh • Die shape: T-shaped, lip width 550mm, lip spacing 0.7mm ·Set temperature: C1 / C2 / C3 / D=170℃ / 240℃ / 260℃ / 260℃ (Evaluation: Judgment Criteria) A (Good): More than 85% of the lip width B (Fair): More than 82.5% and less than 85% of the lip width C (Somewhat poor): More than 80% and less than 82.5% of the lip width D (Poor): Less than 80% of the lip width

[0115] (10) Melting point measurement The crude dried product of EVOH obtained in the synthesis example was dried at 120 °C for 12 hours using a vacuum dryer. For the vacuum-dried EVOH, a differential scanning calorimeter "Q2000" manufactured by TA Instruments was used. The temperature was raised from 30 °C to 250 °C at a rate of 10 °C / min, cooled at 50 °C / min, and then the melting point was determined from the peak temperature measured during the second heating. When measuring the EVOH pellets obtained in Synthesis Example 9, the measurement was carried out without vacuum drying.

[0116] (11) Measurement of oxygen transmission rate (OTR) at the center of the film <Single-layer film preparation conditions> For the dried resin composition pellets containing inorganic particles obtained in the examples and comparative examples, films were formed under the following conditions to obtain single-layer films with a thickness of 20 μm. (Extruder conditions) · L / D: 26, single-screw extruder with a diameter of 40 mm · Screw: Full flight · Screw rotation speed: 30 rpm · Screen mesh: 50 mesh / 100 mesh / 50 mesh · Die shape: T-shaped, lip width 550 mm, lip gap 0.7 mm · Set temperature: C1 / C2 / C3 / D = 170 °C / 230 °C / 230 °C / 230 °C · Take-up roll temperature: 80 °C · Take-up roll speed: 10 - 11 m / min <OTR (Oxygen transmission rate) measurement> For the obtained single-layer film with a thickness of 20 μm, a sample was cut out in a circular shape with a diameter of 90 mm centered on the center of the width direction, conditioned under the conditions of 20 °C and 65% RH, and then the oxygen transmission rate measuring device ("OX-Tran2 / 20" manufactured by ModernControl, detection lower limit 0.01 mL / (m2 Using a daytime atm ()()(day·atm), oxygen permeability was measured at 20°C and 65% RH in accordance with ISO 14663-2 annex C.

[0117] (12) Width-direction uniformity of OTR For the single-layer film used in the measurement in (11), a circular sample with a diameter of 90 mm was cut out with the center 70 mm from the edge of the film, and the OTR was measured under the same conditions as in (11). The difference between this sample and the OTR of the central sample was taken, and the magnitude of the difference was evaluated in three stages from A to C. (Evaluation: Judgment Criteria) A: The difference is less than 10% B: Difference between 10% and less than 15% C: Difference of 15% or more

[0118] (13) Measurement of inorganic vapor deposition layer thickness <Preparation of biaxially oriented film> The dry resin composition pellets containing inorganic particles obtained in the examples and comparative examples were melted at 240°C in a uniscrew extruder and extruded from the die onto a casting roll. Simultaneously, air was blown onto the pellets using an air knife at a wind speed of 30 m / s to obtain an unstretched film with a thickness of 170 μm. The obtained unstretched film was brought into contact with 80°C hot water for 10 seconds, stretched 3.2 times in the longitudinal direction and 3.0 times in the transverse direction using a tenter-type simultaneous biaxial stretcher in a 90°C atmosphere, and then heat-treated for 5 seconds in a tenter set to 170°C. The film ends were then cut to obtain a roll of biaxially oriented film (average thickness 12 μm, width 50 cm, roll length 4,000 m). <Fabrication of vapor-deposited films> Using the biaxially oriented film obtained above, aluminum was deposited onto one side of the film using ULVAC, Inc.'s "Batch-type Deposition Equipment EWA-105" at a film surface temperature of 38°C and a film travel speed of 200 m / min to obtain a laminate (deposited film). <Measurement of Inorganic Vapor Deposition Layer Thickness> The laminate (vapor-deposited film) was cut with a microtome to expose the cross-section. This cross-section was observed using a scanning electron microscope (SEM) (ZEISS ULTRA 55, manufactured by S.I.I. Nanotechnology Co., Ltd.), and the average thickness of the inorganic vapor-deposited layer was measured using a backscattered electron detector. The average thickness was calculated from the average of the thicknesses measured at 10 arbitrary locations.

[0119] (14) Evaluation of the ability to suppress deposition defects A roll of laminated material (vapor-deposited film) was put through a slitter, and while shining a 100W fluorescent lamp from the bottom of the film, it was unwound. The number of vapor deposition defects was measured at 10 different locations in a 0.5m wide, 2m long area, and the average value was calculated per 1m. 2 The number of deposition defects per unit area was used as the basis for evaluating the deposition defect suppression performance based on the number of deposition defects. (Judgment criteria) A:0~50 pieces / m 2 B:51~100 pieces / m 2 C: 101 or more pieces / m 2

[0120] (15) Measurement of adhesion strength The laminate (vapor-deposited film) was cut to A4 size, and a dry laminating adhesive (a mixture of Mitsui Chemicals, Inc.'s "Takelac® A-385" and "Takenate® A-50" in a 1 / 6 mass ratio, resulting in an ethyl acetate solution with a solid content of 23% by mass) was applied to the surface of the inorganic vapor-deposited layer using a bar coater. After hot-air drying at 50°C for 5 minutes, it was laminated with PET film (Toyobo E5000) using a nip roll heated to 80°C. At this time, half of the film was left unbonded by sandwiching aluminum foil between the inorganic vapor-deposited layer and the PET film. After that, it was cured at 40°C for 72 hours to obtain a laminated film. The obtained laminated film was cut into 100mm x 15mm strips centered on the boundary of the aluminum vapor deposition. Of the obtained strips, the laminate and the edge of the PET film in the unbonded portion were grasped, and a T-type peel test was performed five times on a tensile testing machine (Shimadzu Corporation "AUTOGRAPH AGS-H") at a tensile speed of 10 mm / min. The average of the obtained measurements was taken as the adhesion strength and evaluated according to the following criteria. (Judgment criteria) A: 500g / 15mm or more B: 350g / 15mm or more, 500g / less than 15mm C: 350g / less than 15mm

[0121] (16) Evaluation of fracture resistance One hundred rolls of biaxially oriented film (average thickness 12 μm, width 50 cm, roll length 4,000 m) manufactured using the above evaluation method (13) were prepared. The obtained biaxially oriented films were put through a slitter, and the number of breaks when the film rolls were wound under a tension of 100 N / m was used to evaluate the break resistance according to the following criteria. In cases A to C, the break resistance can be evaluated as sufficient. (Judgment criteria) A: 0-1 times / 100 bottles B: 2~4 times / 100 pieces C: 5~7 times / 100 pieces D: 8~10 times / 100 pieces E: 11 times or more / 100 bottles

[0122] <Synthesis Example 1> In a 200L pressurized reactor equipped with a jacket, stirrer, nitrogen inlet, ethylene inlet, and initiator addition port, 75.0 kg of vinyl acetate (hereinafter sometimes referred to as VAc) and 7.2 kg of methanol (hereinafter sometimes referred to as MeOH) were charged, and the reactor was purged with nitrogen by bubbling with nitrogen for 30 minutes. Next, after adjusting the temperature inside the reactor to 65°C, ethylene was introduced so that the reactor pressure (ethylene pressure) reached 4.13 MPa, and 9.4 g of 2,2'-azobis(2,4-dimethylvaleronitrile) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., "V-65") was added as a polymerization initiator to start polymerization. During polymerization, the ethylene pressure was maintained at 4.13 MPa and the polymerization temperature at 65°C. After 4 hours, when the conversion rate of VAc (polymerization rate based on VAc) reached 49.7%, the reactor was cooled, and a solution of 0.2 g of copper acetate dissolved in 20 kg of methanol was added to the container to stop the polymerization. After opening the reaction vessel and removing the ethylene, nitrogen gas was bubbled through to completely remove the ethylene. Next, the polymerization solution was withdrawn from the container and diluted with 20 L of MeOH. This solution was fed from the top of a column-type container, and MeOH vapor was fed from the bottom of the column to remove any unreacted monomers remaining in the polymerization solution along with the MeOH vapor, thereby obtaining an MeOH solution of ethylene-vinyl acetate copolymer (hereinafter sometimes referred to as EVAc).

[0123] Next, 150 kg of a 20% by mass MeOH solution of EVAc was charged into a 300 L reaction vessel equipped with a jacket, stirrer, nitrogen inlet, reflux condenser, and solution addition port. The temperature of this solution was raised to 60°C while blowing nitrogen gas into it, and a 2 N sodium hydroxide MeOH solution was added at a rate of 450 mL / min for 2 hours. After the addition of the sodium hydroxide MeOH solution was completed, the temperature in the system was maintained at 60°C, and the saponification reaction was allowed to proceed by stirring for 2 hours while draining the MeOH and methyl acetate produced in the saponification reaction out of the reaction vessel. After that, 8.7 kg of acetic acid was added to stop the saponification reaction.

[0124] Subsequently, while heating and stirring at 80°C, 120 L of deionized water was added to drain MeOH from the reaction vessel and precipitate EVOH. The EVOH precipitated by decantation was collected and pulverized using a pulverizer. The obtained EVOH powder was placed in a 1 g / L aqueous acetic acid solution (bath ratio 20: 20 L of aqueous solution per 1 kg of powder) and stirred and washed for 2 hours. This was then dehydrated and placed in another 1 g / L aqueous acetic acid solution (bath ratio 20) and stirred and washed for 2 hours. The dehydrated mixture was then placed in deionized water (bath ratio 20), stirred and washed for 2 hours, and dehydrated. This process was repeated three times to purify the EVOH. The electrical conductivity of the washing solution was 3 μS / cm (measured with "CM-30ET" from Toa Denpa Kogyo Co., Ltd.). Next, the purified product was immersed in 250 L of an aqueous solution containing 0.5 g / L of acetic acid and 0.1 g / L of sodium acetate for 4 hours with stirring, then drained, and dried at 60°C for 16 hours to obtain 16.1 kg of crude dried EVOH.

[0125] The above procedure for synthesizing EVOH was repeated to obtain 15.9 kg of crude dried EVOH, resulting in a total of 32.0 kg of crude dried EVOH(A1). The ethylene unit content, degree of saponification, and melting point of the crude dried EVOH(A1) were measured according to the methods described in evaluation methods (1) and (10) above. The results are shown in Table 2.

[0126] <Synthesis Examples 2-8> The size of the pressurized reaction vessel, the amounts of VAc and MeOH charged, the ethylene pressure, the amount of polymerization initiator added, the temperature inside the reaction vessel (temperature during polymerization), the reaction time, the conversion rate of VAc, the amount of EVAc MeOH solution charged in the saponification step, and the rate of addition of sodium hydroxide MeOH solution are as shown in Table 1. Except that the synthesis was performed only once, the crude dried products of each EVOH(A2) to EVOH(A8) were obtained in the same manner as in Synthesis Example 1. The ethylene unit content, degree of saponification, and melting point of the crude dried products of EVOH(A2) to EVOH(A8) were measured according to the methods described in Evaluation Methods (1) and (10) above. The results are shown in Table 2.

[0127] <Synthesis Example 9> Using the apparatus described in paragraph

[0158] and Figure 1 of Japanese Patent Publication No. 2003-231715, EVOH(A9) pellets were prepared by the following procedure. A TEM-35BS extruder (37 mmφ, L / D=52.5) ​​manufactured by Toshiba Machine Co., Ltd. was used. Barrel C1 was water-cooled, barrels C2-C3 were set to 200°C, and barrels C4-C15 were set to 240°C, and the extruder was operated at a screw rotation speed of 400 rpm. Dry resin composition pellets obtained in Reference Example 38, described later, were fed through the resin feed port of C1 and melted. After that, water and oxygen were removed from vent 1, and epoxypropane was fed as a modifying agent 2 through the hydraulic inlet of C9. Then, unreacted epoxypropane was removed from vent 2, pelletized, and hot-air dried at 80°C for 2 hours to obtain 8 mol% modified EVOH(A9) pellets. The obtained EVOH(A9) pellets were measured for ethylene unit content, degree of saponification, epoxypropane modification amount (amount relative to total vinyl alcohol units), and melting point according to the methods described in evaluation methods (1) and (10) above. The results for ethylene unit content, degree of saponification, and melting point are shown in Table 2. The epoxypropane modification amount (content of structural units (x) relative to total vinyl alcohol units) was 8 mol%.

[0128] [Table 1]

[0129] [Table 2]

[0130] <Reference example 1> In a 60L stirring tank equipped with a jacket, stirrer, and reflux condenser, 2 kg of the crudely dried EVOH(A1) obtained in Synthesis Example 1, 0.8 kg of water, and 2.2 kg of MeOH were charged and stirred at 60°C for 5 hours until completely dissolved. Sorbic acid, crotonaldehyde, 2,4-hexadienal, and 2,4,6-octatrienal were added to the resulting solution. This solution was extruded through a 4 mm diameter gold plate into a water / MeOH = 90 / 10 mixture cooled to -5°C to precipitate in strand form, and these strands were cut into pellets with a strand cutter to obtain hydrated EVOH pellets. The moisture content of the obtained hydrated EVOH pellets was measured using a Mettler halogen moisture meter "HR73" and was found to be 52% by mass.

[0131] The obtained hydrated EVOH pellets were placed in a 1 g / L aqueous acetic acid solution (bath ratio 20) and stirred and washed for 2 hours. After desaturation, the pellets were placed again in a 1 g / L aqueous acetic acid solution (bath ratio 20) and stirred and washed for 2 hours. After desaturation, the aqueous acetic acid solution was replaced and the same procedure was repeated. The pellets washed in aqueous acetic acid solution and then desaturated were placed in deionized water (bath ratio 20) and stirred and washed for 2 hours, and desaturated. This process was repeated three times until the electrical conductivity of the washing solution was 3 μS / cm or less (measured with Toa Denpa Kogyo Co., Ltd.'s "CM-30ET"), thereby obtaining hydrated EVOH pellets from which the catalyst residue from the saponification reaction had been removed.

[0132] The obtained water-containing pellets were placed in an aqueous solution (bath ratio 20) with a sodium acetate concentration of 0.510 g / L, an acetic acid concentration of 0.8 g / L, and a phosphoric acid concentration of 0.04 g / L, and immersed for 4 hours with periodic stirring to perform chemical treatment. These pellets were dehydrated and dried at 80°C for 3 hours and at 105°C for 16 hours under a nitrogen stream with an oxygen concentration of 1 vol% or less to obtain cylindrical (average diameter 2.8 mm, average height 3.2 mm) dried resin composition pellets containing EVOH(A1), acetic acid, phosphoric acid, sodium ions (sodium salt), crotonaldehyde, 2,4-hexadienal, 2,4,6-octatrienal, and sorbic acid. The obtained dried resin composition pellets were evaluated according to the methods described in evaluation methods (2) to (9) above. The sodium ion content in the dried resin composition pellets was 100 ppm, the phosphoric acid content was 40 ppm (calculated as phosphate root), and the acetic acid content was 200 ppm. The content of each component other than EVOH is based on the EVOH content. Other evaluation results are shown in Table 3. The amounts of each component added were adjusted so that the content of crotonaldehyde, 2,4-hexadienal, 2,4,6-octatrienal, and sorbic acid were as shown in Table 3.

[0133] <Reference Examples 2~61, Reference Comparative Examples 1~4, 6~24> Dry resin composition pellets were prepared and evaluated in the same manner as in Reference Example 1, except that the types of EVOH (A), unsaturated aliphatic aldehydes (B), conjugated polyene compounds (C), and boric acid content were adjusted to match those shown in Tables 3 to 10. For the 800 ppm boric acid content, an aqueous solution containing sodium acetate, etc. (bath ratio 20) was prepared to a boric acid concentration of 0.25 g / L. For the 1800 ppm boric acid content, an aqueous solution containing sodium acetate, etc. (bath ratio 20) was prepared to a boric acid concentration of 0.57 g / L. The sodium ion content of EVOH in each dry resin composition pellet was 100 ppm, the phosphoric acid content was 40 ppm (based on phosphate root), and the acetic acid content was 200 ppm. Other evaluation results are shown in Tables 3 to 10. The content of each component other than EVOH is based on the EVOH content.

[0134] <Reference Example 5> Dry resin composition pellets were prepared and evaluated in the same manner as in Reference Example 1, except that crotonaldehyde, 2,4-hexadienal, and 2,4,6-octatrienal were not added, and the catalyst residue from the saponification reaction had been removed. The hydrated EVOH pellets were placed in methanol (bath ratio 10), stirred and washed for 2 hours, and dehydrated. This process was repeated twice, and the resulting pellets were placed in ion-exchanged water (bath ratio 20), stirred and washed for 2 hours, and dehydrated. This process was repeated three times. The sodium ion content in the dry resin composition pellets was 100 ppm, the phosphoric acid content was 40 ppm (based on phosphate root), and the acetic acid content was 200 ppm. The content of each component other than EVOH is based on the EVOH content. Other evaluation results are shown in Table 3. The content of crotonaldehyde, 2,4-hexadienal, 2,4,6-octatrienal, and sorbic acid was below the detection limit.

[0135] [Table 3]

[0136] [Table 4]

[0137] [Table 5]

[0138] [Table 6]

[0139] [Table 7]

[0140] [Table 8]

[0141] [Table 9]

[0142] [Table 10]

[0143] From the reference examples and reference comparison examples, it can be seen that when b1 / (b2+b3) is between 2.0 and less than 150.0, neck-in resistance is good, the smaller b1+b2+b3 is, the lower the YI, the lower the content of the conjugated polyene compound (C) c, the lower the YI, and when b2+2b3 is 0.65 ppm or less, die build-up is suppressed.

[0144] A more detailed examination based on Table 3 reveals the following: Reference Comparative Example 5, which does not contain unsaturated aliphatic aldehyde (B), and Reference Comparative Examples 1-3 and 6-9, which contain various unsaturated aliphatic aldehydes (B) individually, do not suppress neck-in. Similarly, Reference Comparative Example 10, where the value of b1 / (b2+b3) is less than 2.0, also does not suppress neck-in. On the other hand, as can be seen from the reference examples, neck-in is suppressed when the value of b1 / (b2+b3) is in the range of 2.0 or more and less than 150.0, and in particular, neck-in is most suppressed when the value of b1 / (b2+b3) is around 10 (for example, 8.0 or more and 13.0 or less), as in Reference Examples 4, 5, 13, 14, 21, and 24. Furthermore, in Comparative Example 4, where b2+2b3 exceeds 0.65 ppm, dye buildup is not suppressed, whereas, as can be seen from the reference examples, when b2+2b3 is 0.65 ppm or less, dye buildup is suppressed, and in particular, when b2+2b3 is 0.10 ppm or less, dye buildup is suppressed more effectively. In addition, regarding the total content of crotonaldehyde (B1), 2,4-hexadienal (B2), and 2,4,6-octatrienal (B3), b1+b2+b3, as can be seen from Comparative Example 4, Reference Examples 1-7, 12-26, etc., it can be seen that the lower the total content, the better the hue. Furthermore, from Reference Examples 6, 9-11, it can be seen that a smaller content of conjugated polyene compounds results in better hue.

[0145] <Preparation of inorganic particles (D)> Synthetic silica; "Silysia® 380" (average particle size 9.0 μm) or "Silysia® 310P" (average particle diameter 2.7 μm) from Fuji Silysia Chemical Co., Ltd. were subjected to pulverization and sieving classification to produce inorganic particles with average particle diameters of 1.6 μm and 4.9 μm. "Silysia® 310P" was also used as the inorganic particle with an average particle diameter of 2.7 μm. In all cases, the average particle diameter was measured using a laser method.

[0146] <Example 1> To the dry resin composition pellets obtained in Reference Example 5, inorganic particles (D) with an average particle size of 2.7 μm were added to achieve a content of 300 ppm based on the EVOH (A) content, and the mixture was dry-blended using a tumbler. This dry-blended mixture was extruded using a 30 mmφ twin-screw extruder (TEX-30SS-30CRW-2V, manufactured by Japan Steel Works Ltd.) at an extrusion temperature of 220°C under a nitrogen atmosphere to obtain dry resin composition pellets containing inorganic particles. The obtained dry resin composition pellets containing inorganic particles were evaluated according to the methods described in evaluation methods (5) to (9) and (11) to (16) above. The evaluation results are shown in Tables 11 and 12.

[0147] <Examples 2-11, Comparative Examples 1-3> Except for changing the dry resin composition pellets, inorganic particle content, and average particle size of the reference example or reference comparative example used, a dry resin composition pellet containing inorganic particles was obtained in the same manner as in Example 1, and each evaluation was performed. The results are shown in Tables 11 and 12.

[0148] [Table 11]

[0149] [Table 12]

[0150] <Example 12> In a 60L stirring tank equipped with a jacket, stirrer, and reflux condenser, 1.6 kg of the crudely dried EVOH(A1) obtained in Synthesis Example 1, 0.4 kg of the crudely dried EVOH(A7) obtained in Synthesis Example 7, 0.8 kg of water, and 2.2 kg of MeOH were charged and stirred at 60°C for 5 hours to completely dissolve. Sorbic acid, crotonaldehyde, 2,4-hexadienal, and 2,4,6-octatrienal were added to the resulting solution. This solution was extruded through a 4 mm diameter gold plate into a water / MeOH = 90 / 10 mixture cooled to -5°C to precipitate in strand form, and these strands were cut into pellets with a strand cutter to obtain hydrated EVOH pellets. The moisture content of the obtained hydrated EVOH pellets was measured using a Mettler halogen moisture meter "HR73" and was found to be 52% by mass.

[0151] The obtained hydrated EVOH pellets were placed in a 1 g / L aqueous acetic acid solution (bath ratio 20) and stirred and washed for 2 hours. After desaturation, the pellets were placed again in a 1 g / L aqueous acetic acid solution (bath ratio 20) and stirred and washed for 2 hours. After desaturation, the aqueous acetic acid solution was replaced and the same procedure was repeated. The pellets washed in aqueous acetic acid solution and then desaturated were placed in deionized water (bath ratio 20) and stirred and washed for 2 hours, and desaturated. This process was repeated three times until the electrical conductivity of the washing solution was 3 μS / cm or less (measured with Toa Denpa Kogyo Co., Ltd.'s "CM-30ET"), thereby obtaining hydrated EVOH pellets from which the catalyst residue from the saponification reaction had been removed.

[0152] The obtained water-containing pellets were placed in an aqueous solution (bath ratio 20) with a sodium acetate concentration of 0.510 g / L, an acetic acid concentration of 0.8 g / L, a phosphoric acid concentration of 0.04 g / L, and a boric acid concentration of 0.05 g / L, and immersed for 4 hours with periodic stirring to perform chemical treatment. These pellets were dehydrated and dried at 80°C for 3 hours and at 105°C for 16 hours under a nitrogen stream with an oxygen concentration of 1 volume% or less to obtain cylindrical (average diameter 2.8 mm, average height 3.2 mm) dried resin composition pellets containing EVOH (A1 and A7), acetic acid, phosphoric acid, sodium ions (sodium salt), crotonaldehyde, 2,4-hexadienal, 2,4,6-octatrienal, and sorbic acid. Using the same method as in Example 1, the dry resin composition pellets and inorganic particles (D) were blended to obtain dry resin composition pellets containing 300 ppm of inorganic particles (D) with an average particle size of 2.7 μm, based on the EVOH (A) content. The obtained dry resin composition pellets containing inorganic particles were evaluated according to the methods described in evaluation methods (2), (3), (5) to (9), and (11) to (16) above. The sodium ion content in the dry resin composition pellets containing inorganic particles was 100 ppm, the phosphoric acid content was 40 ppm (based on the phosphate root), and the acetic acid content was 200 ppm. The content of each component other than EVOH is all based on the EVOH content. Other evaluation results are shown in Tables 13 and 14. The amount of each component added was adjusted so that the content of each component, crotonaldehyde, 2,4-hexadienal, 2,4,6-octatrienal, and sorbic acid, was as shown in Table 13.

[0153] <Examples 14, 16, 17, Comparative Examples 4, 5> As shown in Table 13, dry resin composition pellets containing inorganic particles were prepared and evaluated in the same manner as in Example 12, except that the type of EVOH(Aa), the type of EVOH(Ab), the mass ratio (Aa) / (Ab), the boric acid content, and the unsaturated aldehyde (B) content were changed. The sodium ion content in each dry resin composition pellet containing inorganic particles was 100 ppm, the phosphoric acid content was 40 ppm (calculated as phosphate root), and the acetic acid content was 200 ppm. The content of each component other than EVOH is based on the EVOH content. Other evaluation results are shown in Tables 13 and 14. The boric acid concentration of the aqueous solution used for chemical treatment was adjusted as appropriate so that the boric acid content of the resulting dry resin composition pellets containing inorganic particles was as shown in Table 13.

[0154] <Example 13> 80 parts by mass of dry resin composition pellets obtained in Reference Example 5 and 20 parts by mass of dry resin composition pellets obtained in Reference Example 53 were dry blended to obtain a group of dry resin composition pellets. The obtained group of dry resin composition pellets was extruded using a 30 mmφ twin-screw extruder (TEX-30SS-30CRW-2V manufactured by Japan Steel Works Ltd.) under the conditions of an extrusion temperature of 200°C, a screw rotation speed of 300 rpm, and an extrusion resin rate of 25 kg / hour. After pelletizing, the pellets were hot-air dried at 80°C for 2 hours to obtain dry resin composition pellets. These dry resin composition pellets were blended with inorganic particles (D) in the same manner as in Example 1 to obtain dry resin composition pellets containing inorganic particles (D) with an average particle diameter of 2.7 μm at a concentration of 300 ppm based on the EVOH (A) content. The obtained dry resin composition pellets containing inorganic particles were evaluated according to the evaluation methods described in (2), (3), (5) to (9), and (11) to (16) above. The sodium ion content in the dry resin composition pellets containing inorganic particles was 100 ppm, the phosphoric acid content was 40 ppm (based on phosphate root equivalent), and the acetic acid content was 200 ppm. The content of each component other than EVOH is based on the EVOH content. Other evaluation results are shown in Tables 13 and 14.

[0155] <Example 15> 90 parts by mass of dry resin composition pellets obtained in Reference Example 48 and 10 parts by mass of EVOH(A9) pellets obtained in Synthesis Example 9 were dry blended to obtain a group of dry resin composition pellets. The obtained group of dry resin composition pellets was extruded using a 30 mmφ twin-screw extruder (TEX-30SS-30CRW-2V manufactured by Japan Steel Works Ltd.) under the conditions of an extrusion temperature of 200°C, a screw rotation speed of 300 rpm, and an extrusion resin rate of 25 kg / hour. After pelletizing, the pellets were hot-air dried at 80°C for 2 hours to obtain dry resin composition pellets. These dry resin composition pellets were blended with inorganic particles (D) in the same manner as in Example 1 to obtain dry resin composition pellets containing inorganic particles (D) with an average particle diameter of 2.7 μm at a concentration of 300 ppm based on the EVOH(A) content. The obtained dry resin composition pellets containing inorganic particles were evaluated according to the evaluation methods described in (2), (3), (5) to (9), and (11) to (16) above. The sodium ion content in the dry resin composition pellets containing inorganic particles was 100 ppm, the phosphoric acid content was 40 ppm (based on phosphate root equivalent), and the acetic acid content was 200 ppm. The content of each component other than EVOH is based on the EVOH content. Other evaluation results are shown in Tables 13 and 14.

[0156] [Table 13]

[0157] [Table 14]

[0158] As shown in Tables 11-14, the resin compositions in Examples 1-17 suppressed neck-in and die build-up. The vapor-deposited films in Comparative Examples 1 and 4, which used resin compositions prone to die build-up, had many deposition defects and low adhesion strength of the inorganic vapor-deposited layer. In addition, the single-layer films in Comparative Examples 2 and 5, which used resin compositions prone to neck-in, had low uniformity in the width direction of the OTR. In contrast, in Examples 1-17, which used resin compositions that suppressed die build-up and neck-in and contained inorganic particles, vapor-deposited films were obtained with suppressed deposition defects and high adhesion strength of the inorganic vapor-deposited layer, and the uniformity in the width direction of the OTR in the single-layer films was also improved. In Comparative Example 3, which used a resin composition that suppressed neck-in and die build-up but did not contain inorganic particles, the single-layer film had low break resistance, and the vapor-deposited film also had low adhesion strength of the inorganic vapor-deposited layer. Furthermore, the results from each reference example show that when b1 / (b2+b3) is between 2.0 and less than 150.0, neck-in resistance is good, and when b2+2b3 is 0.65 ppm or less, die build-up is suppressed. Therefore, it can be inferred that any resin composition obtained by adding a predetermined amount of inorganic particles to the resin composition of each reference example will exhibit the same effects as the resin compositions of Examples 1 to 17.

Claims

1. The material contains an ethylene-vinyl alcohol copolymer (A) having an ethylene unit content of 20 mol% to 60 mol%, inorganic particles (D), and crotonaldehyde (B1). It further comprises at least one selected from the group consisting of 2,4-hexadienal (B2) and 2,4,6-octatrienal (B3), The content d of inorganic particles (D) in the ethylene-vinyl alcohol copolymer (A) is 50 ppm or more and 5,000 ppm or less. A resin composition that satisfies the following formulas (1) and (2). 2.0≦b １ / (b ２ +b ３ )<150.0 ・・・(1) b ２ +2b ３ ≦0.65 ・・・(2) In the above formulas (1) and (2), b １ This is the content (ppm) of crotonaldehyde (B1) in ethylene-vinyl alcohol copolymer (A), and b ２ This is the content (ppm) of 2,4-hexadienal (B2) in ethylene-vinyl alcohol copolymer (A), and b ３ This is the content (ppm) of 2,4,6-octatrienal (B3) relative to the ethylene-vinyl alcohol copolymer (A).

2. The total content (b １ + b ２ + b ３ ) of crotonaldehyde (B1), 2,4 - hexadienal (B2) and 2,4,6 - octatrieneal (B3) with respect to the ethylene - vinyl alcohol copolymer (A) is 0.01 ppm or more and 7.0 ppm or less. The resin composition according to claim 1.

3. Crotonaldehyde (B1) content b １ The resin composition according to claim 1 or 2, wherein the concentration is 0.01 ppm or more and 4.0 ppm or less.

4. Content of 2,4-hexadienal (B2) ２ The resin composition according to claim 1 or 2, wherein the concentration is 0.005 ppm or more and 0.65 ppm or less.

5. Content of 2,4,6-octatrienal (B3) ３ The resin composition according to claim 1 or 2, wherein the amount is 0.325 ppm or less.

6. The resin composition according to claim 1 or 2, further comprising a conjugated polyene compound (C), wherein the content c of the conjugated polyene compound (C) relative to the ethylene-vinyl alcohol copolymer (A) is 1 ppm or more and less than 300 ppm.

7. The resin composition according to claim 6, wherein the conjugated polyene compound (C) is sorbic acid.

8. The ethylene-vinyl alcohol copolymer (A) comprises ethylene-vinyl alcohol copolymer (Aa) and ethylene-vinyl alcohol copolymer (Ab), The difference in melting points (Aa-Ab) between the ethylene-vinyl alcohol copolymer (Aa) and the ethylene vinyl alcohol copolymer (Ab) is 8°C or more. The resin composition according to claim 1 or 2, wherein the mass ratio (Aa / Ab) of ethylene-vinyl alcohol copolymer (Aa) to ethylene-vinyl alcohol copolymer (Ab) is 60 / 40 or more and 95 / 5 or less.

9. The ethylene unit content of the ethylene-vinyl alcohol copolymer (Aa) is 20 mol% or more and 50 mol% or less, and the ethylene unit content of the ethylene-vinyl alcohol copolymer (Ab) is 30 mol% or more and 60 mol% or less. The resin composition according to claim 8, wherein the difference in ethylene unit content (Ab-Aa) between the ethylene-vinyl alcohol copolymer (Ab) and the ethylene vinyl alcohol copolymer (Aa) is 4.5 mol% or more.

10. A single-layer film comprising the resin composition according to claim 1 or 2.

11. The single-layer film according to claim 10, which is a biaxially oriented film.

12. A laminate having the single-layer film described in claim 10 and other layers.

13. The laminate according to claim 12, wherein the other layer is an inorganic vapor-deposited layer.

Images