Acetalization product of ethylenevinyl alcohol copolymer, composition containing said acetalization product, and barrier material

Abstract

The present invention pertains to an acetalization product of an ethylenevinyl alcohol copolymer. The acetalization product contains 20-80 mol% of an ethylene unit and 4-76 mol% of a vinyl alcohol unit with reference to all monomeric units constituting the acetalization product, has a degree of acetalization of 3-80 mol%, satisfies formula (1): 0.71≤W0.05h / 2f≤1.09 [W0.05h / 2f represents a symmetry factor determined by reverse-phase partition gradient high-performance liquid chromatography analysis in accordance with JIS K 0124:2011 using a water-ethanol eluant] and formula (2): 1.20≤Tm / Tg≤1.35 [Tm and Tg represent a melting peak temperature (K) and a midpoint glass transition temperature (K), respectively, measured in accordance with JIS K7121:2012], and exhibits an oxygen permeation rate of at most 150 cc·20 μm / m2·day·atm at 20°C and 65%RH.

Description

Acetalized product of ethylene-vinyl alcohol copolymer, composition containing said acetalized product, and barrier material

[0001] This patent application claims priority under the Paris Convention to Japanese Patent Application No. 2022-166255 (filing date: October 17, 2022), the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to an acetalized product of an ethylene-vinyl alcohol copolymer and a method for producing the same, a composition containing the acetalized product, a resin film comprising a layer containing the acetalized product, a resin film comprising a layer containing the composition, a barrier material made of the resin film, and a molded article made of the resin film.

[0003] Ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as EVOH) has excellent transparency and gas barrier properties, but has the drawback of lacking stretchability and flexibility. To overcome this drawback, a method is known in which EVOH is blended with a flexible resin such as an ethylene-vinyl acetate copolymer or an ethylene-propylene copolymer. However, this method has the drawback of significantly reducing heat resistance or transparency.

[0004] Furthermore, Patent Document 1 discloses an ethylene-vinyl alcohol copolymer modified with a monofunctional epoxy compound (e.g., 1,2-epoxybutane or epoxypropane) having a molecular weight of 500 or less, and states that the modified ethylene-vinyl alcohol copolymer is excellent in barrier properties, transparency, stretchability, flexibility, and flex resistance. Patent Document 2 discloses an ethylene-vinyl alcohol-vinyl acetal copolymer having an excellent combination of hot water resistance and oxygen barrier properties, and a packaging material formed from an olefin-vinyl alcohol-vinyl acetal copolymer having an excellent combination of hot water resistance and oxygen barrier properties.

[0005] JP 2006-233222 A JP 55-46642 A

[0006] However, according to the investigations of the present inventors, it has been found that the barrier properties, transparency, stretchability, flexibility and heat resistance of films containing the copolymers obtained using the above-mentioned conventional techniques are not always sufficient, and there is room for improvement.

[0007] Therefore, an object of the present invention is to provide an acetalized product of an ethylene-vinyl alcohol copolymer that can form a resin film excellent in all of barrier properties, transparency, stretchability, flexibility, and heat resistance.

[0008] The present inventors have conducted extensive research to solve the above problems and have arrived at the present invention. That is, the present invention includes the following preferred embodiments: [1] An acetalized product of an ethylene-vinyl alcohol copolymer, comprising, based on all monomer units constituting the acetalized product, 20 to 80 mol % of ethylene units and 4 to 76 mol % of vinyl alcohol units, the degree of acetalization being 3 to 80 mol %, and satisfying the formula (1): 0.71≦W ０．０５ｈ / 2f≦1.09 (1) [In formula (1), W ０．０５ｈ / 2f represents a symmetry coefficient determined by reversed-phase partition gradient high-performance liquid chromatography analysis using a water-ethanol eluent in accordance with JIS K 0124:2011] and formula (2): 1.20≦Tm / Tg≦1.35 (2) [in formula (2), Tm and Tg represent the melting peak temperature (Kelvin) and the midpoint glass transition temperature (Kelvin), respectively, measured in accordance with JIS K7121:2012], and the oxygen transmission rate at 20°C and 65% RH is 150 cc·20 μm / m ２An acetalized product having a viscosity of 1000 sq ft (J / g) x Tm (Kelvin) x amount of vinyl alcohol units (mol%) / 100} / (oxygen transmission rate at 20°C and 65% RH) ≥ 30 (3). [3] The acetalized product according to [1] or [2], having a degree of acetalization of 40 mol% or less. [4] The acetalized product according to any one of [1] to [3], having a melting peak temperature Tm of 136°C or higher as measured in accordance with JIS K7121:2012. [5] The acetalized product according to any one of [1] to [4], having a tensile modulus of elasticity of 2000 MPa or less at 23°C and 50% RH. [6] A composition comprising: (A) the acetalized product according to any one of [1] to [5] above; and (B) one or more resins selected from the group consisting of: (B-1) an acetalized product of an ethylene-vinyl alcohol copolymer other than (A); (B-2) an ethylene-vinyl alcohol copolymer; and (B-3) a resin other than (B-1) and (B-2). [7] A method for producing the acetalized product according to any one of [1] to [5] above, comprising: (i) preparing a dispersion containing an ethylene-vinyl alcohol copolymer, an aldehyde, and a solvent, and impregnating the ethylene-vinyl alcohol copolymer with at least a portion of the aldehyde; and (ii) after step (i), adding a catalyst to the dispersion to acetalize the ethylene-vinyl alcohol copolymer, wherein the acetalization is carried out by a solid-liquid reaction. [8] A resin film comprising one or more layers containing the acetalized product according to any one of [1] to [5] above. [9] A resin film comprising one or more layers containing the composition according to [6] above.

[10] The resin film according to [8] above, further comprising one or more layers containing one or more resins selected from the group consisting of polyolefins, polyamides, polyesters, and polyurethanes.

[11] The resin film according to [9] above, further comprising one or more layers containing one or more resins selected from the group consisting of polyolefins, polyamides, polyesters, and polyurethanes.

[12] A barrier material comprising the resin film according to any one of [8] to

[11] above.

[13] A molded article made of the resin film according to any one of [8] to

[11] above.

[0009] According to the present invention, there can be provided an acetalized product of an ethylene-vinyl alcohol copolymer, which can form a resin film excellent in all of barrier properties, transparency, stretchability, flexibility and heat resistance.

[0010] FIG. 1 shows an example of the measurement results of high performance liquid chromatography (HPLC) for explaining the symmetry coefficient.

[0011] Hereinafter, embodiments of the present invention will be described in detail. Note that the scope of the present invention is not limited to the embodiments described herein, and various modifications can be made without departing from the spirit of the present invention. Furthermore, when multiple upper and lower limit values ​​are specified for a specific parameter, any of these upper and lower limit values ​​can be combined to form a suitable numerical range.

[0012] [Acetalized Product of Ethylene-Vinyl Alcohol Copolymer] The acetalized product of the ethylene-vinyl alcohol copolymer of the present invention (hereinafter also simply referred to as "acetalized product") is a copolymer represented by the following formulas (1) and (2): ０．０５ｈ / 2f≦1.09 (1) [In formula (1), W ０．０５ｈ and 2f represents a symmetry coefficient determined by reversed-phase partition gradient high-performance liquid chromatography analysis using a water-ethanol eluent in accordance with JIS K 0124:2011. 1.20≦Tm / Tg≦1.35 (2) (where Tm and Tg represent the melting peak temperature (Kelvin) and the midpoint glass transition temperature (Kelvin), respectively, measured in accordance with JIS K7121:2012.) The oxygen transmission rate at 20°C and 65% RH is 150 cc·20 μm / m ２ ・day・atm or less.

[0013] The inventors have found that the oxygen transmission rate at 20°C and 65% RH is 150 cc·20 μm / m ２The present inventors have surprisingly found that when an acetalized product of an ethylene-vinyl alcohol copolymer having a viscosity of 1000 psi (1000 psi) or less is prepared, a resin film (resin sheet) containing the acetalized product is excellent in all of barrier properties, transparency, stretchability, flexibility, and heat resistance.

[0014] The acetalized product of the present invention has a symmetry coefficient W determined in accordance with JIS K 0124:2011. ０．０５ｈ Since the symmetry coefficient / 2f is 0.71 to 1.09, the resulting resin film tends to have high transparency. This is thought to be because the symmetry coefficient within the above range imparts an appropriate acetalization degree distribution to the acetalized product. On the other hand, if the symmetry coefficient is outside the above range, the acetalization degree of the resulting acetalized product tends to vary greatly, resulting in a decrease in transparency. Furthermore, if the symmetry coefficient exceeds the above upper limit, the proportion of acetalized products with a high acetalization degree (high acetalization degree components) in the resulting acetalized product increases, which tends to decrease transparency. If the symmetry coefficient is below the above lower limit, the proportion of acetalized products with a low acetalization degree (low acetalization degree components) in the resulting acetalized product increases, which tends to decrease transparency and moldability.

[0015] From the viewpoint of easily improving transparency and moldability, the symmetry coefficient is preferably 1.05 or less, more preferably 1.00 or less, even more preferably 0.95 or less, even more preferably 0.92 or less, and particularly preferably 0.90 or less. Also, from the viewpoint of easily improving transparency and moldability, the symmetry coefficient is preferably 0.73 or more, more preferably 0.75 or more, even more preferably 0.77 or more, even more preferably 0.79 or more, and particularly preferably 0.80 or more. Here, the symmetry coefficient is a coefficient indicating the degree of symmetry of the measured peak obtained using high performance liquid chromatography, and the closer the symmetry coefficient is to 1.0, the higher the symmetry of the peak.

[0016] The symmetry coefficient W ０．０５ｈ / 2f can be determined by reversed-phase gradient high-performance liquid chromatography analysis using a water-ethanol eluent in accordance with JIS K 0124:2011. ０．０５ｈ " represents the peak width at a height (5% peak height position) that is 1 / 20 of the peak height from the baseline of the measurement peak obtained by HPLC analysis, and "f" represents the distance on the rising side of the peak when the peak width at the 5% peak height position is bisected by a perpendicular line including the peak apex. Specifically, in the measurement peak in Figure 1, which is an example of the measurement results of high performance liquid chromatography (HPLC), "W ０．０５ｈ ” is the peak width W shown in FIG. ０．０５ｈ where "f" represents the distance f between a and b shown in Figure 1. In Figure 1, "a" represents the start point at the 5% height position of the peak, and "b" represents the intersection of the horizontal line including the peak start point a and the vertical line including the peak apex. In Figure 1, the dotted line parallel to the horizontal axis represents the baseline.

[0017] The above HPLC analysis can usually be carried out under the following measurement conditions: Sample concentration: 1.5 mg / 1 g Sample solvent: Ethanol (99.5%) / ion-exchanged water = 9 / 1 wt% mixed solvent Injection volume: 20 μL Detector: Varian 380-LC, EVAP 80°C (preheating), NEB 50°C (second-stage heating), Gas 1.5 (SLM), data acquisition interval 1000 ms, filter 1 μm ODS silica column: Shimadzu Corporation "Shinpack G-ODS (octadecyl group-modified spherical fully porous silica gel, inner diameter 4 mm × length 10 mm, particle size 5 μm)" Column temperature: 45°C Flow rate: Total flow rate 0.4 mL / min

[0018] The HPLC analysis of the present invention can be performed by the following procedure. Liquids of different polarities are used as the mobile phases. Water is used as mobile phase A, and ethanol (99.5%) is used as mobile phase B. Before the sample is injected, the inside of the HPLC system column is filled with a mixed solvent of mobile phase A / mobile phase B in a volume ratio of 95 / 5. The sample is injected in this state. The solvent is then allowed to flow under the following conditions: 0-5 minutes (B concentration: constant 5%) 5-25 minutes (B concentration: 5-100%) 25-30 minutes (B concentration: constant 100%) 30-31 minutes (B concentration: 100-5%) 31-55 minutes (B concentration: constant 5%)

[0019] The symmetry coefficient can be adjusted by appropriately adjusting the distribution of the acetalization degree in the acetalized product and / or the production conditions of the acetalized product, etc. For example, the symmetry coefficient may be adjusted to fall within the above range by selecting a production method for an acetalized product of an ethylene-vinyl alcohol copolymer, which will be described later, particularly an acetalization method described as a preferred embodiment in the following description.

[0020] The acetalized product of the present invention has a Tm / Tg ratio (the ratio of the melting peak temperature (Kelvin) to the midpoint glass transition temperature (Kelvin)) of 1.20 to 1.35, as measured in accordance with JIS K7121:2012, and therefore can ensure flexibility and heat resistance while maintaining the transparency of the resulting resin film. This is thought to be because, while higher crystallinity generally leads to improved heat resistance but tends to reduce flexibility and transparency, by setting the Tm / Tg of the acetalized product within the above range, the acetalized product is endowed with appropriate crystallinity that can achieve transparency, flexibility, and heat resistance all at once. On the other hand, if the Tm / Tg (K / K) exceeds the above upper limit, transparency is likely to decrease, and if it is below the above lower limit, heat resistance is likely to decrease.

[0021] The Tm / Tg (K / K) is preferably 1.34 or less, more preferably 1.33 or less, and even more preferably 1.32 or less, from the viewpoint of easily improving transparency. Furthermore, the Tm / Tg (K / K) is preferably 1.22 or more, more preferably 1.25 or more, from the viewpoint of easily improving heat resistance. The Tm / Tg (K / K) can be determined by measuring the melting peak temperature (Kelvin) and midpoint glass transition temperature (Kelvin) using a differential scanning calorimeter (DSC) in accordance with JIS K7121:2012. Alternatively, the Tm / Tg (K / K) may be determined by measuring the melting peak temperature (Kelvin) and midpoint glass transition temperature (Kelvin) and converting these values ​​to Kelvin (K), or by the method described in the examples.

[0022] In the acetalized product of the present invention, the melting peak temperature Tm (°C) measured in accordance with JIS K7121:2012 is preferably 136°C or higher, more preferably 138°C or higher, even more preferably 140°C or higher, still more preferably 142°C or higher, and particularly preferably 145°C or higher, and is preferably 180°C or lower, more preferably 175°C or lower, even more preferably 170°C or lower, and still more preferably 165°C or lower. When the melting peak temperature Tm is equal to or higher than the above lower limit, heat resistance such as retort resistance is likely to be improved, and when it is equal to or lower than the above upper limit, transparency and moldability are likely to be improved.

[0023] In the acetalized product of the present invention, the midpoint glass transition temperature Tg (°C) measured in accordance with JIS K7121:2012 is preferably 20°C or higher, more preferably 30°C or higher, even more preferably 40°C or higher, and preferably 80°C or lower, more preferably 60°C or lower, and even more preferably 50°C or lower. When the midpoint glass transition temperature Tg is equal to or higher than the above-mentioned lower limit, moldability (e.g., film formability) is likely to be improved, and when it is equal to or lower than the above-mentioned upper limit, the flexibility of the obtained resin film is likely to be improved.

[0024] The Tm / Tg(K / K) can be adjusted by appropriately adjusting the distribution of the acetalization degree in the acetalized product and / or the production conditions of the acetalized product, etc. For example, the Tm / Tg(K / K) may be adjusted to fall within the above range by selecting a production method for an acetalized product of an ethylene-vinyl alcohol copolymer, which will be described later, particularly an acetalization method described as a preferred embodiment in the explanation below.

[0025] The ethylene unit content of the acetalized product of the present invention is 20 to 80 mol% relative to all monomer units constituting the acetalized product. When the ethylene unit content is within the above range, the flexibility and barrier properties of the resulting resin film and the moldability of the acetalized product are easily improved. From the viewpoint of easily improving the flexibility, barrier properties, and transparency of the resulting resin film and the moldability of the acetalized product, the ethylene unit content may be preferably 25 mol% or more, more preferably 27 mol% or more, even more preferably 30 mol% or more, and even more preferably 32 mol% or more. From the viewpoint of easily improving heat resistance, the ethylene unit content may be preferably 60 mol% or less, more preferably 55 mol% or less, even more preferably 50 mol% or less, even more preferably 48 mol% or less, particularly preferably 46 mol% or less, and even more preferably 44 mol% or less.

[0026] The content of vinyl alcohol units in the acetalized product of the present invention is 4 to 76 mol% relative to all monomer units constituting the acetalized product. When the content of vinyl alcohol units is within the above range, the transparency and barrier properties of the resulting resin film are likely to be improved. From the viewpoint of easily improving barrier properties, the content of vinyl alcohol units may be preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, still more preferably 30 mol% or more, particularly preferably 33 mol% or more, even more particularly preferably 36 mol% or more, even more particularly preferably 38 mol% or more, and even more particularly preferably 40 mol% or more relative to all monomer units constituting the acetalized product. Furthermore, from the viewpoint of easily improving the transparency of the resulting acetalized product, the content may be preferably 75 mol% or less, more preferably 70 mol% or less, even more preferably 65 mol% or less, particularly preferably 60 mol% or less, and even more particularly preferably 58 mol% or less.

[0027] The content of acetal units (acetalized vinyl alcohol units) in the acetalized product of the present invention may be, from the viewpoint of easily suppressing the crystallinity of the acetalized product and enhancing flexibility and transparency, preferably 1 mol% or more, more preferably 1.5 mol% or more, even more preferably 2.5 mol% or more, still more preferably 3 mol% or more, particularly preferably 4 mol% or more, more particularly preferably 5 mol% or more, and even particularly preferably 7 mol% or more, relative to all monomer units constituting the acetalized product; and, from the viewpoint of easily enhancing heat resistance and barrier properties (gas barrier properties), may be preferably 70 mol% or less, more preferably 60 mol% or less, even more preferably 50 mol% or less, still more preferably 40 mol% or less, particularly preferably 30 mol% or less, more particularly preferably 25 mol% or less, and even particularly preferably 20 mol% or less.

[0028] The acetalized product of the present invention may contain a vinyl ester unit such as a vinyl acetate unit, and the content of the vinyl ester unit may be preferably 0 to 5 mol %, more preferably 0 to 2 mol %, and even more preferably 0 to 1 mol %, from the viewpoint of thermal decomposition resistance.

[0029] The acetalized product of the present invention may contain other monomer units in addition to the ethylene units, vinyl alcohol units, and acetal units, as well as optional vinyl ester units, to the extent that the effects of the present invention are not impaired. Examples of other monomer units include α-olefins such as propylene, isobutylene, α-octene, and α-dodecene; unsaturated acids such as acrylic acid, methacrylic acid, methyl methacrylate, crotonic acid, maleic 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 ethylene sulfonic acid, allyl sulfonic acid, and methallylsulfonic acid, or their salts; alkyl vinyl ethers, vinyl ketone, N-vinylpyrrolidone, vinyl chloride, and vinylidene chloride. When the ethylene-vinyl alcohol copolymer contains other monomer units, the content thereof may be preferably 15 mol % or less, more preferably 10 mol % or less.

[0030] The content of each unit in the acetalized product can be determined by NMR measurement, for example, by the method described in the Examples.

[0031] The degree of acetalization of the acetalized product is 3 to 80 mol%. When the degree of acetalization is within the above range, the transparency, flexibility, heat resistance, and barrier properties of the resulting resin film are likely to be improved. From the viewpoint of keeping the crystallinity of the acetalized product low and easily increasing transparency and flexibility, the degree of acetalization may be preferably 4 mol% or more, more preferably 5 mol% or more, even more preferably 7 mol% or more, and even more preferably 10 mol% or more. From the viewpoint of easily increasing heat resistance and barrier properties, the degree of acetalization may be preferably 70 mol% or less, more preferably 62 mol% or less, even more preferably 60 mol% or less, still more preferably 50 mol% or less, particularly preferably 40 mol% or less, and even more particularly preferably 35 mol% or less (e.g., 30 mol% or less, 28 mol% or less, 26 mol% or less, 24 mol% or less, 22 mol% or less, less than 22 mol%, 20 mol% or less, 18 mol% or less, 16 mol% or less, or less than 16 mol%). The acetalization degree in the present invention refers to the ratio of acetal units to the total content of acetal units, vinyl alcohol units, and vinyl ester units such as vinyl acetate units in an acetalized product. Specifically, the acetalization degree in the present invention can be calculated by the following formula: Acetalization degree (mol %)={k / (k+l+m)}×100, where k is the content of acetal units, l is the content of vinyl alcohol units, and m is the content of vinyl ester units.

[0032] The oxygen transmission rate (hereinafter also referred to as "OTR") of the acetalized product at 20°C and 65% RH is 150cc 20µm / m ２ The oxygen transmission rate is 150cc / 20μm / m or less. ２ The oxygen permeation rate of 120 cc·day·atm or less indicates that the resulting resin film has high barrier properties against gases (particularly oxygen). ２ · day · atm or less, more preferably 100cc · 20μm / m ２ · day · atm or less, more preferably 75cc · 20μm / m ２ · day · atm or less, even more preferably 50cc · 20μm / m ２· day · atm or less, particularly preferably 40cc · 20μm / m ２ day·atm or less, more particularly preferably 35 cc·20 μm / m ２ · day · atm or less, more particularly preferably 30 cc · 20 μm / m ２ The lower limit of the oxygen transmission rate is not particularly limited, and is, for example, 0 cc·20 μm / m ２ ・Day・atm or more is also acceptable.

[0033] The oxygen transmission rate at 20°C and 65% RH can be adjusted by appropriately adjusting the production conditions of the acetalized product, etc. For example, the oxygen transmission rate may be adjusted to the upper limit or less by selecting a production method for an acetalized product of an ethylene-vinyl alcohol copolymer described below, particularly an acetalization method described as a preferred embodiment in the explanation below. The oxygen transmission rate at 20°C and 65% RH can be measured using an oxygen transmission measuring device, for example, by the method described in the Examples described below.

[0034] In one embodiment of the present invention, the acetalized product of the present invention has a viscosity of 1000 MPa (300 MPa) based on the following formula (3): {ΔH (J / g) × Tm (Kelvin) × vinyl alcohol unit amount (mol%) / 100} / OTR (cc 20 μm / m ２ It is preferable to satisfy the following condition: (day·atm)≧30 (3).

[0035] In formula (3), ΔH represents the heat of crystalline fusion of the acetalized product measured in accordance with JIS K7121:2012. More specifically, it represents the heat of crystalline fusion measured using a DSC when the temperature is increased from 25°C to 140°C at a heating rate of 10°C / min, held at 140°C for 30 minutes, then decreased from 140°C to -30°C at a heating rate of 4°C / min, and then increased again from -30°C to 200°C at a heating rate of 10°C / min. The amount of vinyl alcohol units can be determined by NMR measurement, for example, by the method described in the Examples.

[0036] From the viewpoint of making it easier to improve the properties of the obtained resin film, the value of {ΔH×Tm×amount of vinyl alcohol units / 100} / OTR is preferably 50 or more, more preferably 70 or more, and even more preferably 100 or more (for example, 150 or more, 250 or more). The reason why the properties of the obtained resin film, particularly heat resistance and barrier properties, are likely to be improved when the value of {ΔH×Tm×amount of vinyl alcohol units / 100} / OTR is equal to or greater than the above lower limit is not clear, and is not limited to the reasons described below, but is thought to be because the acetalized product has an appropriate crystalline structure that provides heat resistance and barrier properties. The upper limit of {ΔH×Tm×amount of vinyl alcohol units / 100} / OTR is not particularly limited, but is usually 10,000 or less.

[0037] The value of {ΔH × Tm × amount of vinyl alcohol units / 100} / OTR can be adjusted by appropriately adjusting the production conditions of the acetalized product, etc. For example, the value of {ΔH × Tm × amount of vinyl alcohol units / 100} / OTR may be adjusted to be equal to or greater than the lower limit by selecting a production method for an acetalized product of an ethylene-vinyl alcohol copolymer, which will be described later, particularly an acetalization method described as a preferred embodiment in the explanation below (particularly an acetalization method employing a preferred specific surface area and / or a preferred average particle size of the raw material EVOH and / or a preferred aldehyde impregnation time and / or a preferred acetalization reaction time and / or a preferred acetalization catalyst concentration), etc.

[0038] The acetalized product has a tensile modulus of preferably 2000 MPa or less, more preferably 1800 MPa or less, and even more preferably 1600 MPa or less, as measured by tensile strength and elongation at 23°C and 50% RH. The lower limit of the tensile modulus is not particularly limited, and from the viewpoint of ease of handling as a film, it is preferably 10 MPa or more, more preferably 100 MPa or more, even more preferably 300 MPa or more, still more preferably 500 MPa or more, particularly preferably 650 MPa or more, and even more particularly preferably 800 MPa or more. The acetalized product has a tensile breaking elongation of preferably 150% or more, more preferably 200% or more, even more preferably 250% or more, and particularly preferably 300% or more, as measured by tensile strength and elongation at 23°C and 50% RH. The upper limit of the tensile breaking elongation is not particularly limited, and is usually 1000% or less. The use of such an acetalized product makes it possible to obtain a flexible film or molded product, which can be easily subjected to secondary processing when stretched or thermoformed. The tensile modulus and tensile elongation at break can be measured by the method described in the Examples below. The tensile modulus and tensile elongation at break can be adjusted by appropriately adjusting the production conditions of the acetalized product, etc. For example, the tensile modulus and tensile elongation at break can be adjusted to be equal to or lower than the upper limit, and the tensile elongation at break can be adjusted to be equal to or higher than the lower limit, by selecting the production method of the acetalized product of an ethylene-vinyl alcohol copolymer described below, particularly the acetalization method described as a preferred embodiment in the explanation below.

[0039] In one embodiment of the present invention, the melt flow rate (MFR) of the acetalized product, measured in accordance with JIS K7210:2014 under conditions of 190°C and 2.16 kg, is preferably 1 to 30 g / 10 min, more preferably 1.5 to 20 g / 10 min, even more preferably 2 to 10 g / 10 min, and still more preferably 2.5 to 9 g / 10 min, from the viewpoint of easily suppressing thermal deterioration during molding processing of the acetalized product.

[0040] As described above, the acetalized product of the present invention exhibits a low oxygen transmission rate, a low tensile modulus, a high tensile elongation at break, and a high melting peak temperature. Furthermore, a resin film obtained from the acetalized product of the present invention exhibits values ​​similar to those of the resin film of the present invention, as described later in the section "Resin Film, Barrier Material, and Molded Article." Therefore, the acetalized product of the present invention can form a resin film that is excellent in all of barrier properties, transparency, stretchability, flexibility, and heat resistance.

[0041] [Method for Producing Acetalized Product of Ethylene-Vinyl Alcohol Copolymer] The method for producing the acetalized product of the present invention is not particularly limited, and may be, for example, a method comprising the steps of: (i) preparing a dispersion containing an ethylene-vinyl alcohol copolymer, an aldehyde, and a solvent, and impregnating the ethylene-vinyl alcohol copolymer with at least a portion of the aldehyde; and (ii) after step (i), adding a catalyst to the dispersion to acetalize the ethylene-vinyl alcohol copolymer, wherein the acetalization is carried out by a solid-liquid reaction.

[0042] <Step (i)> Step (i) is a step of preparing a dispersion containing an ethylene-vinyl alcohol copolymer, an aldehyde, and a solvent (hereinafter also referred to as "EVOH dispersion") and impregnating at least a portion of the aldehyde into the ethylene-vinyl alcohol copolymer. By mixing the ethylene-vinyl alcohol copolymer and the aldehyde in the dispersion and bringing them into sufficient contact, at least a portion of the aldehyde can be impregnated into the ethylene-vinyl alcohol copolymer.

[0043] In the method of the present invention, the EVOH contained in the EVOH dispersion may be porous or non-porous. When a porous ethylene-vinyl alcohol copolymer (hereinafter referred to as "porous EVOH" or simply "porous") is used as a raw material, EVOH can be easily acetalized uniformly, and the symmetry coefficient of the resulting acetalized product can be easily adjusted within the above-mentioned range. Therefore, even when solid EVOH is acetalized by a heterogeneous method, intermolecular crosslinking of EVOH is unlikely to occur, and an acetalized product with excellent transparency can be obtained. This is thought to be because, by using a porous EVOH, when at least a portion of the aldehyde described below is impregnated into EVOH, the aldehyde (acetalizing agent) penetrates not only the solid surface of the EVOH but also the solid interior of the EVOH through the pores, thereby enabling uniform acetalization of EVOH. As a result, the difference in the degree of acetalization between the solid surface and the solid interior of the acetalized product obtained by acetalization is small, resulting in an acetalized product with a narrow distribution of the degree of acetalization.

[0044] In the present invention, the EVOH porous body is preferably an EVOH having a large number of pores, and it is also preferable that some or all of the pores have openings on the surface of the porous body.

[0045] In one embodiment of the present invention, the median diameter of pores in the EVOH porous material is preferably 0.005 μm or more, more preferably 0.01 μm or more, and even more preferably 0.02 μm or more, from the viewpoint of easily uniformly acetalizing EVOH and improving the transparency of the resulting acetalized EVOH. Furthermore, the median diameter is preferably 1 μm or less, more preferably 0.5 μm or less, even more preferably 0.2 μm or less, still more preferably less than 0.2 μm, particularly preferably 0.18 μm or less, especially more preferably 0.15 μm or less, and particularly preferably 0.12 μm or less, from the viewpoint of easily maintaining strength of the porous material and therefore being less likely to disintegrate and turn into powder during the production process of the acetalized EVOH, thereby less likely to cause blockage of the production line, and facilitating efficient production of the acetalized product. The median pore diameter is the median diameter (d50) of all pores in the log differential pore volume (logarithmic differential pore volume) distribution with a pore diameter in the range of 0.005 to 100 μm. The reason why the reference pore diameter is set to the range of 0.005 to 100 μm is that the pore distribution with a pore diameter larger than 100 μm is mainly voids between particles, and the pore distribution with a pore diameter of less than 0.005 μm, which is near the lower limit of measurement, includes pseudopores due to compression, etc.

[0046] The median diameter of the pores of the porous body can be adjusted by the production conditions of the porous body. For example, when an EVOH porous body is produced by preparing a composition containing EVOH and at least one solvent selected from water and alcohol, extruding the composition into a coagulation liquid in the form of strands to coagulate, and cutting the resulting coagulated strands, the median diameter of the porous body can be adjusted by the type and content of the solvent contained in the composition, the linear velocity when the composition is extruded, the extrusion temperature, the cooling rate, etc. Furthermore, the median diameter of these pores can be measured using a pore size distribution analyzer, for example, by the method described in the Examples.

[0047] In one embodiment of the present invention, the pore surface area (specific surface area) of the EVOH porous body in the range of 0.005 to 100 μm as measured by mercury intrusion porosimetry is preferably 25 m from the viewpoint of easily improving the transparency of the acetalized EVOH.２ / g or more, more preferably 30m ２ The pore surface area of ​​the EVOH porous body is preferably 45 m / g or more, from the viewpoint of easily suppressing adhesion of the EVOH porous bodies to each other during high-temperature washing in the manufacturing process of the EVOH porous body. ２ / g or less, more preferably 41m ２ / g or less, more preferably 39m ２ / g or less. The pore surface area of ​​the EVOH porous body in the range of 0.005 to 100 μm can be adjusted by the conditions for producing the porous body. For example, similar to the method for adjusting the median pore diameter of the porous body, it can be adjusted by the type and content of the solvent contained in the composition, the linear velocity when the composition is extruded into a coagulation liquid, the extrusion temperature, the cooling rate, etc. The pore surface area of ​​the EVOH porous body can also be measured using a pore distribution measuring device.

[0048] In one embodiment of the present invention, the pore volume of the EVOH porous body may be preferably 0.1 mL / g or more, more preferably 0.2 mL / g or more, and even more preferably 0.25 mL / g or more, from the viewpoint of uniformly acetalizing EVOH and easily improving the transparency of the resulting acetalized EVOH. Furthermore, from the viewpoint of ease of handling, the pore volume may be preferably 1.0 mL / g or less, more preferably 0.5 mL / g or less, and even more preferably 0.3 mL / g or less. The pore volume of the EVOH porous body can be adjusted by the production conditions of the porous body. For example, similar to the method for adjusting the median pore diameter of the porous body, the pore volume can be adjusted by the type and content of the solvent contained in the composition, the linear velocity and extrusion temperature when the composition is extruded into a coagulation liquid, the cooling rate during coagulation, and the like. The pore volume of the porous body can also be measured using a pore size distribution analyzer.

[0049] In one embodiment of the present invention, the average particle size of the EVOH porous material may be preferably 1 mm or more, more preferably 2 mm or more, and even more preferably 3 mm or more, from the viewpoint of ease of handling. Furthermore, from the viewpoint of facilitating uniform acetalization of EVOH and improving the transparency of the resulting acetalized product, the average particle size may be preferably 10 mm or less, more preferably 7 mm or less, and even more preferably 5 mm or less. The average particle size can be measured, for example, by the method described in the Examples.

[0050] The shape of the EVOH porous body is not particularly limited, and examples thereof include powder, pellet, flake, bead, and irregular shapes. Among these, the porous body is preferably in powder or pellet form, and more preferably in pellet form. In the present invention, a pellet-like porous body refers to a solid porous body having a substantially uniform size such as a sphere, cylinder, elliptical cylinder, or polygonal cylinder, and its cross section may be circular, elliptical, polygonal, or the like.

[0051] When the EVOH porous material of the present invention is in the form of pellets, the pellet-shaped porous material can be produced by, as described below, a method in which an ethylene-vinyl alcohol copolymer composition is extruded into a coagulation liquid to coagulate into strands, and then the obtained strand-shaped coagulation product is cut to a predetermined length with a strand cutter or the like, or by a method in which the ethylene-vinyl alcohol copolymer composition is directly cut in a molten state.

[0052] Examples of ethylene-vinyl alcohol copolymers include those obtained by copolymerizing ethylene with a vinyl ester monomer and saponifying the resulting copolymer. In one embodiment of the present invention, the ethylene content of the ethylene-vinyl alcohol copolymer (hereinafter also referred to as the ethylene unit content) is preferably 20 to 80 mol% relative to all monomer units constituting the EVOH. Furthermore, from the viewpoint of easily improving the moldability of the resulting acetalized product or the flexibility, barrier properties, and transparency of the resulting resin film, the ethylene content may be preferably 20 mol% or more, more preferably 25 mol% or more, even more preferably 30 mol% or more, and particularly preferably 32 mol% or more (e.g., 35 mol% or more). Furthermore, from the viewpoint of easily improving the heat resistance of the resulting acetalized product, the ethylene content may be preferably 80 mol% or less, more preferably 60 mol% or less, even more preferably 55 mol% or less, particularly preferably 50 mol% or less, even more preferably 48 mol% or less, even more particularly preferably 44 mol% or less, even more particularly preferably 42 mol% or less, even more particularly preferably 38 mol% or less, and most preferably 36 mol% or less.

[0053] The saponification degree of EVOH is not particularly limited, but from the viewpoint of thermal decomposition resistance, it is preferably 95 mol% or more, more preferably 98 mol% or more, even more preferably 99 mol% or more, and particularly preferably 99.9 mol% or more. The upper limit of the saponification degree is not particularly limited, and may be, for example, 100 mol% or less.

[0054] The content of vinyl alcohol units in the ethylene-vinyl alcohol copolymer may be preferably 40 mol% or more, more preferably 45 mol% or more, and even more preferably 50 mol% or more, based on all monomer units constituting the EVOH, from the viewpoint of easily improving the barrier properties of the resulting acetalized product; and may be preferably 80 mol% or less, more preferably 75 mol% or less, even more preferably 70 mol% or less, particularly preferably 65 mol% or less, and even more particularly preferably 55 mol% or less, from the viewpoint of easily improving the transparency of the resulting acetalized product.

[0055] In the present invention, the ethylene-vinyl alcohol copolymer may contain, in addition to ethylene units, vinyl alcohol units, and vinyl ester units, monomer units derived from monomers copolymerizable with these units (hereinafter also referred to as "other monomer units"), within a range that does not impair the effects of the present invention. Examples of the other monomer units include the same monomer units as the other monomer units that may be contained in the acetalized product. When the ethylene-vinyl alcohol copolymer contains other monomer units, the content thereof may be preferably 15 mol% or less, more preferably 10 mol% or less.

[0056] The contents of ethylene units, vinyl alcohol units and other monomer units optionally contained in the EVOH of the present invention can be determined by NMR measurement, for example, by the method described in the examples.

[0057] The copolymerization form of the ethylene-vinyl alcohol copolymer is not particularly limited, and may be any of a random copolymer, an alternating copolymer, a block copolymer, a graft copolymer, and the like.

[0058] In one embodiment of the present invention, the melt flow rate of the ethylene-vinyl alcohol copolymer, measured in accordance with JIS K7210:2014 under conditions of 190°C and 2.16 kg, may be preferably 1 to 30 g / 10 min, more preferably 1.5 to 20 g / 10 min, even more preferably 2 to 10 g / 10 min, and particularly preferably 2.5 to 9 g / 10 min, from the viewpoint of easily suppressing thermal deterioration during molding of the resulting acetalized product.

[0059] The method for producing the ethylene-vinyl alcohol copolymer porous body is not particularly limited, and it can be produced by a known method. As an example, a method for producing a pellet-shaped EVOH porous body will be described.

[0060] As described in, for example, Japanese Patent Application Laid-Open No. 11-293077 or Japanese Patent Application Laid-Open No. 2002-121290, the pellet-shaped EVOH porous body can be produced by a step of preparing a composition containing an ethylene-vinyl alcohol copolymer and at least one solvent selected from water and alcohol, a step of extruding the composition into a coagulation liquid in the form of a strand, solidifying it, and then cutting it, or a method of directly cutting the composition in a molten state.

[0061] The EVOH contained in the composition can be obtained by copolymerizing ethylene with a vinyl ester monomer and saponifying the resulting copolymer. Examples of vinyl ester monomers used as raw materials for EVOH include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl versatate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl oleate, and vinyl benzoate. Among these, vinyl acetate is preferred. The method for copolymerizing ethylene with a vinyl ester monomer is not particularly limited, and copolymerization may be performed by a conventionally known method, such as solution polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization. The polymerization initiator that can be used in the copolymerization can be appropriately selected from conventionally known polymerization initiators, such as azo initiators, peroxide initiators, and redox initiators, depending on the polymerization method. The saponification of the copolymer of ethylene and a vinyl ester monomer can be carried out by a conventionally known method such as alcoholysis or hydrolysis using an alkali catalyst or an acid catalyst. Among these, saponification using methanol as a solvent and caustic soda (NaOH) as a catalyst is preferred because it is simple.

[0062] The alcohol that can be contained in the composition is not particularly limited as long as it is a solvent that can dissolve EVOH, and examples thereof include methanol, ethanol, propanol, isopropanol, etc. Among these alcohols, alcohols having a boiling point of 100° C. or less are preferred, and methanol is particularly preferred, because they have a low boiling point and are easily removed.

[0063] When the composition contains water as a solvent, it may be prepared by directly adding water to EVOH or to a composition containing EVOH and an alcohol, or by concentrating an EVOH alcohol solution obtained by dissolving EVOH in an alcohol as necessary and then adding water to the EVOH alcohol solution in an amount that does not cause EVOH to precipitate. Alternatively, a composition containing EVOH and water, or EVOH, water, and an alcohol may be obtained by introducing water vapor into EVOH or a composition containing EVOH and an alcohol and discharging at least a portion of the alcohol together with the water vapor.

[0064] The alcohol that can be used to prepare the EVOH alcohol solution is not particularly limited as long as it is a solvent that can dissolve EVOH, and examples thereof include the same alcohols that can be contained in the composition. Alcohols with a boiling point of 100°C or less are preferred, and methanol is particularly preferred, because they have a low boiling point and are easy to remove. The content of the alcohol in the EVOH alcohol solution may be preferably 1 to 500 parts by mass, more preferably 5 to 200 parts by mass, per 100 parts by mass of EVOH.

[0065] When the composition contains water, the content of water is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 50 parts by mass or more, per 100 parts by mass of EVOH, from the viewpoint of facilitating uniform acetalization of EVOH and facilitating removal of the neutralization salt produced by neutralization after the acetalization reaction. Furthermore, from the viewpoint of facilitating efficient production of an acetalized product, which tends to increase the strength of the resulting porous body, the content of water is preferably 500 parts by mass or less, more preferably 300 parts by mass or less, and even more preferably 200 parts by mass or less.

[0066] When the composition contains an alcohol, the content of the alcohol is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 50 parts by mass or more, per 100 parts by mass of EVOH, from the viewpoints of facilitating uniform acetalization of EVOH and facilitating removal of the neutralization salt produced by neutralization after the acetalization reaction. Furthermore, from the viewpoints of facilitating efficient production of an acetalized product, which tends to increase the strength of the resulting porous body, the content of the alcohol is preferably 500 parts by mass or less, more preferably 300 parts by mass or less, and even more preferably 200 parts by mass or less.

[0067] The coagulating liquid for coagulating the composition is not particularly limited as long as it is a solvent capable of coagulating EVOH, but it is preferable to use water, alcohol, or a mixed solvent of water and alcohol as the coagulating liquid.

[0068] The temperature of the coagulation liquid is preferably 0 to 50°C, more preferably 0 to 30°C, from the viewpoint of facilitating sufficient coagulation of the composition. Furthermore, the temperature of the composition when extruded into the coagulation liquid is preferably 90 to 150°C, more preferably 95 to 140°C, from the viewpoint of the fluidity of EVOH. As described above, by extruding the composition into the coagulation liquid and coagulating it, the obtained coagulated body is a porous body with aligned pores.

[0069] The resulting strand-like coagulated body may be cut, for example, by a strand cutter or the like, and by cutting the resulting strand-like coagulated body with a strand cutter or the like, pellets of the EVOH porous body can be obtained.

[0070] Examples of a method for directly cutting the composition in a molten state to obtain pelletized EVOH porous material include a method for obtaining pelletized EVOH porous material by extruding the molten composition from an extruder using a hot-cut method, a hot-cut method in water, etc. As described above, by extruding and pelletizing the molten composition, the obtained pellets become porous material with oriented pores.

[0071] The method for producing the powdery EVOH porous material is not particularly limited, and for example, the powdery EVOH porous material may be obtained by pulverizing the pellet-like porous material obtained by the above-mentioned method using a pulverizer or the like.

[0072] The EVOH porous body may contain a solvent, but when the contained solvent is a good solvent for EVOH, it is preferable that the amount of the good solvent in the EVOH is reduced to an extent that the pores of the EVOH porous body are not blocked by drying, etc. When the contained solvent is a poor solvent for EVOH, such as water, the EVOH porous body may contain 5 to 200 parts by mass of the poor solvent, such as water, per 100 parts by mass of the EVOH porous body.

[0073] In the method of the present invention, when a non-porous ethylene-vinyl alcohol copolymer (a non-porous body is one having no pores) (hereinafter also referred to as a "non-porous EVOH body" or simply a "non-porous body") is used as a raw material, the EVOH can be acetalized uniformly and the symmetry coefficient of the resulting acetalized product can be adjusted to fall within the above-mentioned range by selecting an acetalization method (in particular, an acetalization method employing a preferred specific surface area and / or a preferred average particle size and / or a preferred aldehyde impregnation time and / or a preferred acetalization reaction time and / or a preferred acetalization catalyst concentration of the raw material EVOH). Therefore, even when solid EVOH is acetalized by a heterogeneous method, intermolecular crosslinking of the EVOH is unlikely to occur, and an acetalized product with excellent transparency can be obtained.

[0074] In one embodiment of the present invention, from the viewpoint of handleability, the average particle size of the non-porous EVOH material may be preferably 0.8 μm or more, more preferably 1.0 μm or more, even more preferably 10 μm or more, and particularly preferably 50 μm or more. The average particle size is preferably 1 mm or less, more preferably 0.5 mm or less, even more preferably 0.4 mm or less, and particularly preferably 0.3 mm or less. When the average particle size of the non-porous EVOH material is the above-mentioned upper limit or less, uniform acetalization of the EVOH is facilitated, and the transparency of the resulting acetalized product is likely to be improved. This is thought to be because, by using a non-porous EVOH having a larger specific surface area due to an average particle size not exceeding the upper limit, the proportion of the center of the non-porous EVOH where acetalization does not or does not proceed easily can be reduced, and when at least a portion of the aldehyde described below is impregnated into EVOH, the aldehyde serving as the acetalizing agent penetrates into the irregularities or gaps normally present on the surface of the non-porous EVOH, thereby allowing acetalization to proceed even inside the non-porous EVOH and achieving more uniform acetalization, resulting in an acetalized product with a narrow distribution. The average particle size can be measured, for example, by the method described in the Examples.

[0075] The shape of the EVOH non-porous material is not particularly limited, and examples thereof include powder, pellet, flake, bead, and irregular shapes. Among these, the non-porous material is preferably in the form of powder or pellet. In the present invention, a pellet-like non-porous material refers to a solid non-porous material having a substantially uniform size, such as a sphere, cylinder, elliptical cylinder, or polygonal pillar, and its cross section may be circular, elliptical, polygonal, or the like.

[0076] When the non-porous EVOH material of the present invention is in the form of pellets, the pellet-shaped non-porous material can be produced by, as described below, a method in which an ethylene-vinyl alcohol copolymer composition is extruded into a coagulation liquid to coagulate into strands, and then the obtained strand-shaped coagulation product is cut to a predetermined length with a strand cutter or the like, or by a method in which the ethylene-vinyl alcohol copolymer composition is directly cut in a molten state.

[0077] Examples of ethylene-vinyl alcohol copolymers include those obtained by copolymerizing ethylene with a vinyl ester monomer and saponifying the resulting copolymer. In one embodiment of the present invention, the ethylene content of the ethylene-vinyl alcohol copolymer (hereinafter also referred to as the ethylene unit content) is preferably 20 to 80 mol% relative to all monomer units constituting the EVOH. Furthermore, from the viewpoint of easily improving the moldability of the resulting acetalized product or the flexibility, barrier properties, and transparency of the resulting resin film, the ethylene content may be preferably 20 mol% or more, more preferably 25 mol% or more, even more preferably 30 mol% or more, and particularly preferably 32 mol% or more (e.g., 35 mol% or more). Furthermore, from the viewpoint of easily improving the heat resistance of the resulting acetalized product, the ethylene content may be preferably 80 mol% or less, more preferably 60 mol% or less, even more preferably 55 mol% or less, particularly preferably 50 mol% or less, even more preferably 48 mol% or less, even more particularly preferably 44 mol% or less, even more particularly preferably 42 mol% or less, and even more particularly preferably 38 mol% or less.

[0078] The saponification degree of EVOH is not particularly limited, but from the viewpoint of thermal decomposition resistance, it is preferably 95 mol% or more, more preferably 98 mol% or more, even more preferably 99 mol% or more, and particularly preferably 99.9 mol% or more. The upper limit of the saponification degree is not particularly limited, and may be, for example, 100 mol% or less.

[0079] The content of vinyl alcohol units in the ethylene-vinyl alcohol copolymer may be preferably 40 mol% or more, more preferably 45 mol% or more, and even more preferably 50 mol% or more, based on all monomer units constituting the EVOH, from the viewpoint of easily improving the barrier properties of the resulting acetalized product; and may be preferably 80 mol% or less, more preferably 75 mol% or less, even more preferably 70 mol% or less, particularly preferably 65 mol% or less, and even more particularly preferably 55 mol% or less, from the viewpoint of easily improving the transparency of the resulting acetalized product.

[0080] In the present invention, the ethylene-vinyl alcohol copolymer may contain, in addition to ethylene units, vinyl alcohol units, and vinyl ester units, monomer units derived from monomers copolymerizable with these units (hereinafter also referred to as "other monomer units"), within a range that does not impair the effects of the present invention. Examples of the other monomer units include the same monomer units as the other monomer units that may be contained in the acetalized product. When the ethylene-vinyl alcohol copolymer contains other monomer units, the content thereof may be preferably 15 mol% or less, more preferably 10 mol% or less.

[0081] The contents of ethylene units, vinyl alcohol units and other monomer units optionally contained in the EVOH of the present invention can be determined by NMR measurement, for example, by the method described in the examples.

[0082] The copolymerization form of the ethylene-vinyl alcohol copolymer is not particularly limited, and may be any of a random copolymer, an alternating copolymer, a block copolymer, a graft copolymer, and the like.

[0083] In one embodiment of the present invention, the melt flow rate of the ethylene-vinyl alcohol copolymer, measured in accordance with JIS K7210:2014 under conditions of 190°C and 2.16 kg, may be preferably 1 to 30 g / 10 min, more preferably 1.5 to 20 g / 10 min, even more preferably 2 to 10 g / 10 min, and particularly preferably 2.5 to 9 g / 10 min, from the viewpoint of easily suppressing thermal deterioration during molding of the resulting acetalized product.

[0084] The method for producing the non-porous ethylene-vinyl alcohol copolymer is not particularly limited, and it can be produced by a known method.

[0085] The method for producing the powdery non-porous EVOH material is not particularly limited, and the powdery non-porous EVOH material may be obtained, for example, by pulverizing a non-porous or porous material obtained by a known method using a pulverizer, etc. Whether the pulverized porous material is a powdery non-porous EVOH material, i.e., whether it has no pores, can be confirmed, for example, by observation with an electron microscope.

[0086] In one embodiment of the present invention, the content of EVOH contained in the EVOH dispersion prepared in step (i) is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and is preferably 70% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, based on the total mass of the dispersion.

[0087] The aldehyde contained in the EVOH dispersion is not particularly limited, and examples thereof include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, hexylaldehyde, benzaldehyde, isobutyraldehyde, 2-ethylhexylaldehyde, 2-methylbutyraldehyde, trimethylacetaldehyde, 2-methylpentylaldehyde, 2,2-dimethylbutyraldehyde, 2-ethylbutyraldehyde, 3,5,5-trimethylhexylaldehyde, n-hexylaldehyde, n-octylaldehyde, n-nonylaldehyde, n-decylaldehyde, and n-dodecylaldehyde.

[0088] Alternatively, it may be an aldehyde having a reactive carbon-carbon double bond, examples of which include acrolein, methacrolein, crotonaldehyde, 3-butenal, 2-methyl-2-butenal, 2-methyl-3-butenal, 2,2-dimethyl-3-butenal, 3-methyl-2-butenal, 3-methyl-3-butenal, 2-pentenal, 2-methyl-2-pentenal, 3-pentenal, and 3-methyl-4-pentenal. nal, 4-pentenal, 4-methyl-4-pentenal, 2-hexenal, 3-hexenal, 4-hexenal, 5-hexenal, 7-octenal, 10-undecenal, 2-ethylcrotonaldehyde, 3-(dimethylamino)acrolein, myristoleinaldehyde, palmitoleinaldehyde, oleinaldehyde, elaidinaldehyde, vaccenaldehyde, gadoleinaldehyde, erucaldehyde Alkenals having 3 to 30 carbon atoms, preferably alkenals having 3 to 25 carbon atoms, such as 2,4-pentadienal, 2,4-hexadienal, 2,6-nonadienal, and citral; alkadienals having 5 to 30 carbon atoms, preferably alkadienals having 5 to 25 carbon atoms, such as 2,4-pentadienal, 2,4-hexadienal, 2,6-nonadienal, and citral; linolenic aldehyde, eleostearic aldehyde, unsaturated aldehydes such as alkatrienals having 7 to 30 carbon atoms, preferably alkatrienals having 7 to 25 carbon atoms, such as aldehyde; alkatetraenals having 9 to 30 carbon atoms, preferably alkatetraenals having 9 to 25 carbon atoms, such as stearidone aldehyde and arachidone aldehyde; and alkpentaenals having 11 to 30 carbon atoms, preferably alkpentaenals having 11 to 25 carbon atoms, such as eicosapentaene aldehyde.

[0089] The aldehyde contained in the EVOH dispersion may be an aldehyde derivative. Examples of aldehyde derivatives include those in which a hydroxy group and an aldehyde group form an acetal or hemiacetal within the molecule. An aldehyde derivative in which a hydroxy group and an aldehyde group form an acetal or hemiacetal within the molecule has a cyclic structure, and one or two of the carbon atoms constituting the ring may be substituted with an alkyl group, preferably a methyl group or an ethyl group, more preferably a methyl group. Examples of specific aldehyde derivatives include 2-hydroxytetrahydrofuran, 2-hydroxytetrahydropyran, 4-methyl-2-hydroxytetrahydrofuran, and 4-methyl-2-hydroxytetrahydropyran.

[0090] These aldehydes may be used alone or in combination of two or more. In one embodiment of the present invention, the aldehyde is preferably butyl aldehyde, isobutyl aldehyde, or n-octyl aldehyde, from the viewpoint of easily improving the flexibility, heat resistance, and transparency of the resulting acetalized product. Isobutyl aldehyde and n-octyl aldehyde are particularly preferred, as they can achieve a high level of balance between the flexibility, heat resistance, and barrier properties of the resulting acetalized product.

[0091] The content of the aldehyde contained in the EVOH dispersion is not particularly limited and may be appropriately adjusted depending on the desired degree of acetalization. In one embodiment of the present invention, the content of the aldehyde may be preferably 1 to 40 parts by mass, more preferably 1.5 to 35 parts by mass, and even more preferably 2 to 30 parts by mass, relative to 100 parts by mass of EVOH, from the viewpoint of easily improving the transparency and flexibility of the resulting acetalized product.

[0092] In the method of the present invention, acetalization is carried out by a solid-liquid reaction, and therefore the solvent contained in the EVOH dispersion is a poor solvent for EVOH and its acetalized product, preferably a solvent containing water, more preferably water.

[0093] The method for preparing the EVOH dispersion is not particularly limited. For example, the EVOH dispersion may be prepared by adding an aldehyde to a dispersion in which EVOH is dispersed in a solvent, or by adding a solvent to a mixture of EVOH and an aldehyde to prepare a dispersion.

[0094] In the method of the present invention, after preparing the EVOH dispersion, at least a portion of the aldehyde is impregnated into an ethylene-vinyl alcohol copolymer before adding a catalyst. This allows the aldehyde to penetrate deep into the porous EVOH or to penetrate into the irregularities or gaps on the surface of the non-porous EVOH, thereby enabling uniform acetalization of the EVOH. This makes it easy to adjust the symmetry coefficient of the resulting acetalized product to fall within the above-mentioned range, and to increase its transparency.

[0095] The temperature at which the aldehyde is impregnated into the EVOH is not particularly limited, but from the viewpoint of enabling the aldehyde to be impregnated into the EVOH more quickly, the temperature may be, for example, 20° C. or higher, preferably 30° C. or higher, more preferably 40° C. or higher, and even more preferably 50° C. or higher. From the viewpoint of preventing fusion of the EVOH molecules, the temperature may be preferably 100° C. or lower, more preferably 90° C. or lower, and even more preferably 80° C. or lower.

[0096] The time for impregnating the aldehyde into the porous EVOH material can be appropriately selected depending on the impregnation temperature, the pore structure of the porous EVOH material, etc., and is preferably 2 hours or more, more preferably 2.5 hours or more, even more preferably 3 hours or more, still more preferably 4 hours or more, and particularly preferably 5 hours or more. There is no particular upper limit, and it may be, for example, 10 hours. The time for impregnating the non-porous EVOH material with the aldehyde can be appropriately selected depending on the impregnation temperature, the average particle size of the non-porous EVOH material, etc., and it is preferably 4 hours or more, more preferably 5 hours or more, even more preferably 6 hours or more, still more preferably 8 hours or more, and particularly preferably 10 hours or more. There is no particular upper limit, and it may be, for example, 24 hours.

[0097] <Step (ii)> Step (ii) is a step of acetalizing EVOH by impregnating EVOH with an aldehyde and then adding a catalyst to the EVOH dispersion prepared in step (i). In the method of the present invention, the acetalization is carried out by a solid-liquid reaction. By carrying out the acetalization by a solid-liquid reaction, the Tm / Tg (K / K) of the resulting acetalized product can be easily adjusted to fall within the above range, which makes it easy to improve flexibility and heat resistance while maintaining transparency. Furthermore, by carrying out the acetalization by a solid-liquid reaction, the resulting acetalized product can be separated from the reaction solution by filtration, making it easy to produce the acetalized product efficiently and in high yield. In the present invention, the method of carrying out acetalization by a solid-liquid reaction refers to a method in which a poor solvent for EVOH and the acetalized product of EVOH produced by acetalization is used as a solvent for the acetalization reaction, thereby obtaining the produced acetalized product as a solid dispersed in a dispersion liquid without dissolving the EVOH and the acetalized product in a solvent in the acetalization step.

[0098] The acetalization catalyst is not particularly limited and may be an inorganic acid or an organic acid, and examples thereof include acid catalysts such as acetic acid, paratoluenesulfonic acid, nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, carbonic acid, etc. Among these catalysts, inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid are preferred from the viewpoints of easily increasing the reaction rate of the acetalization reaction, facilitating washing from the produced acetalized product, and facilitating efficient production of the acetalized product.

[0099] The amount of catalyst added to the EVOH dispersion can be appropriately selected depending on the type of catalyst and / or the reaction temperature. The catalyst concentration in the EVOH dispersion is preferably 0.001 to 1.0 mol / L, more preferably 0.01 to 0.8 mol / L, even more preferably 0.02 to 0.25 mol / L, and still more preferably 0.02 to 0.1 mol / L. The amount of catalyst per 100 parts by mass of EVOH in the EVOH dispersion is preferably 1 to 75 parts by mass, 5 to 50 parts by mass, and even more preferably 7.5 to 35 parts by mass.

[0100] The method for adding the catalyst to the EVOH dispersion is not particularly limited. For example, the catalyst may be added to the EVOH dispersion all at once, or may be added in multiple batches. From the viewpoint of easily obtaining an acetalized product with low haze and excellent transparency and barrier properties, it is preferable to add the catalyst to the EVOH dispersion in multiple batches, and it is particularly preferable to add the catalyst in two batches. When the catalyst is added in multiple batches to the EVOH dispersion, the amount of the catalyst added in the first batch is preferably 50 mass% or less, more preferably 40 mass% or less, and even more preferably 30 mass% or less, of the total amount added. When the amount of the catalyst added in the first batch is not more than the above upper limit, the distribution of the acetalization degree becomes narrow, and the transparency of the obtained acetalized product is likely to be improved.

[0101] The reaction temperature for acetalization is preferably equal to or lower than the glass transition temperature of EVOH, from the viewpoint of easily maintaining the pores of the EVOH porous body and preventing fusion of the EVOH porous body and the EVOH non-porous body during the reaction. The reaction temperature may be more preferably 10 to 80°C, more preferably 20 to 70°C, and even more preferably 30 to 60°C. The acetalization may be carried out in air or in an inert gas such as nitrogen gas or argon gas, and may be carried out under normal pressure, elevated pressure, or reduced pressure.

[0102] After the acetalization reaction, the resulting reaction solution may be neutralized with an alkali as needed, and then the acetalized product may be separated and purified from the reaction solution by a conventional separation method such as filtration, concentration, reprecipitation, or recrystallization. The neutralized salt produced by the neutralization is preferably removed by washing or the like. The alkali that can be used for neutralization is not particularly limited, and examples thereof include sodium hydroxide, potassium hydroxide, ammonia, sodium acetate, sodium carbonate, sodium bicarbonate, and potassium carbonate.

[0103] The acetalization reaction time, i.e., the time from the addition of the catalyst to the completion of the acetalization reaction (until neutralization or separation and purification), is preferably 2 hours or more, more preferably 6 hours or more, even more preferably 8 hours or more, and particularly preferably 12 hours or more. The upper limit of the acetalization reaction time is not particularly limited and may be, for example, 30 hours.

[0104] The present inventors have found that by employing the acetalization method of the preferred embodiment described above, and in particular by adjusting at least one, preferably at least two, and more preferably all of the specific surface area and / or average particle size of the starting EVOH resin, the aldehyde impregnation time, the acetalization catalyst concentration, and the acetalization reaction time within the preferred ranges described above, it is possible to produce an acetalized product capable of forming a resin film that is all excellent in barrier property, transparency, stretchability, flexibility, and heat resistance.

[0105] [Composition] The present invention also covers a composition comprising the acetalized product of the present invention (hereinafter also referred to as "acetalized product (A)" or "(A)") and one or more resins selected from the group consisting of (B) (B-1) an acetalized product of an ethylene-vinyl alcohol copolymer other than (A), (B-2) an ethylene-vinyl alcohol copolymer, and (B-3) a resin other than (B-1) and (B-2).

[0106] The composition of the present invention contains the acetalized product (A), and therefore can form a resin film having excellent barrier properties, transparency, stretchability, flexibility, and heat resistance. The content of the acetalized product (A) in the composition of the present invention may be preferably 5% by mass or more, more preferably 7.5% by mass or more, even more preferably 10% by mass or more, even more preferably 20% by mass or more, and even more preferably 25% by mass or more. When the content of the acetalized product (A) is equal to or greater than the above-mentioned lower limit, a resin film having excellent barrier properties, transparency, stretchability, flexibility, and heat resistance can be easily obtained. The upper limit is not particularly limited and may be, for example, less than 100% by mass.

[0107] Examples of the acetalized ethylene vinyl alcohol copolymer (B-1) other than (A) include those represented by the formula (1), the formula (2), and 150cc·20μm / m ２Examples include acetalized products of ethylene-vinyl alcohol copolymers that do not satisfy one or more of the following oxygen transmission rates at 20°C and 65% RH for 1000 sq. m / s or less. The acetalized product (B-1) may be a resin containing ethylene units, vinyl alcohol units, acetal units, and, in some cases, vinyl ester units. The content of each unit, the degree of acetalization, Tm, Tg, MFR, and tensile modulus of the acetalized product (B-1) may be the same as or different from those described in the section [Acetalized Product of Ethylene-Vinyl Alcohol Copolymer]. The acetalized product (B-1) may be a single product or a combination of two or more products differing in the content of each unit, etc.

[0108] In one embodiment of the present invention, the Tm / Tg(K / K) of the acetalized product (B-1) is preferably less than 1.27, more preferably 1.25 or less, even more preferably 1.23 or less, and particularly preferably 1.21 or less, from the viewpoint of easily improving the transparency of the composition, and is preferably 1.10 or more, more preferably 1.12 or more, and even more preferably 1.15 or more, from the viewpoint of easily improving the heat resistance of the composition. The Tm / Tg(K / K) can be determined by the same method as for the acetalized product (A).

[0109] The content of resin (B-1) in the composition of the present invention is preferably 75 parts by mass or less per 100 parts by mass of the acetalized product (A) from the viewpoint of easily improving the gas barrier properties of the resulting resin film, and may be, for example, 0 parts by mass or more, preferably 10 parts by mass or more, more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, and particularly preferably 25 parts by mass or more per 100 parts by mass of the acetalized product (A) from the viewpoint of easily improving the transparency and / or flexibility.

[0110] Examples of the ethylene-vinyl alcohol copolymer (B-2) include the ethylene-vinyl alcohol copolymers described in the section "Method for producing acetalized ethylene-vinyl alcohol copolymer" as raw materials for the acetalized product of the present invention. However, the ethylene-vinyl alcohol copolymer as resin (B-2) may or may not be porous. The ethylene-vinyl alcohol copolymer (B-2) may be a single copolymer or a combination of two or more copolymers having different unit contents.

[0111] The content of resin (B-2) in the composition of the present invention is preferably 350 parts by mass or less per 100 parts by mass of the acetalized product (A) from the viewpoint of easily improving the flexibility of the resulting resin film, and may be, for example, 0 parts by mass or more, preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, and particularly preferably 100 parts by mass or more per 100 parts by mass of the acetalized product (A) from the viewpoint of easily improving the gas barrier properties and / or heat resistance of the composition.

[0112] Examples of resin (B-3) other than (B-1) and (B-2) include polyolefin resins such as polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, and polynorbornene; ethylene-based ionomers; styrene-based resins such as polystyrene, styrene-maleic anhydride copolymer, high-impact polystyrene, AS resin, ABS resin, AES resin, AAS resin, ACS resin, and MBS resin; methyl methacrylate-based polymers, methyl methacrylate-styrene copolymers; polyethylene terephthalate, polybutylene terephthalate, and the like. phthalate and other polyester resins; polyamides such as nylon 6, nylon 66, and polyamide elastomers; polycarbonate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyacetal, polyvinylidene fluoride, polyurethane, modified polyphenylene ether, polyphenylene sulfide, silicone-modified resins, acrylic rubber, acrylic thermoplastic elastomers, silicone rubber; styrene-based thermoplastic elastomers such as SEPS, SEBS, and SIS; and olefin-based rubbers such as IR, EPR, and EPDM. These resins may be used alone or in combination of two or more.

[0113] Examples of polyamide elastomers include thermoplastic elastomers composed of hard segments made of polyamide and soft segments made of polyether. Examples of polyamides constituting the hard segments include nylon 6, nylon 66, nylon 11, and nylon 12, with nylon 12 being preferred. Examples of polyethers constituting the soft segments include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Commercially available polyamide elastomers may also be used. Examples of commercially available polyamide elastomers include UBESTA (registered trademark) XPA manufactured by Ube Industries, Ltd., and the Pebax (registered trademark) 33 series, 53 series, MV series, MH series, HD series, and MP series manufactured by Arkema K.K.

[0114] The content of resin (B-3) in the composition of the present invention is preferably 100 parts by mass or less per 100 parts by mass of the acetalized product (A), from the viewpoint of easily improving the gas barrier properties of the resulting resin film; and may be, for example, 0 parts by mass or more, preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, and particularly preferably 100 parts by mass or more per 100 parts by mass of the acetalized product (A), from the viewpoint of easily improving the flexibility and / or adhesiveness of the composition.

[0115] Among the resins (B-1) to (B-3), from the viewpoint of easily improving the heat resistance, transparency, and barrier properties of the resulting resin film, the acetalized product of an ethylene-vinyl alcohol copolymer other than (A) (B-1) and the ethylene-vinyl alcohol copolymer (B-2) are preferred, and the ethylene-vinyl alcohol copolymer (B-2) is more preferred, from the viewpoint of easily improving the heat resistance, transparency, and barrier properties of the resulting resin film.

[0116] Various additives can be blended into the composition of the present invention as needed. Examples of such additives include antioxidants, UV absorbers, light stabilizers, alkali metal salts, alkaline earth metal salts, carboxylic acid compounds, phosphate compounds, plasticizers, heat stabilizers, antistatic agents, lubricants, colorants, and fillers. Furthermore, as described below, when crosslinking is to be performed on the composition of the present invention in the resin film, barrier material, or molded article of the present invention, it is preferable to blend a crosslinking aid as an additive. The additives can be blended alone or in combination of two or more. The content of the various additives varies depending on the type and can be appropriately selected within a range that does not impair the effects of the present invention. When additives are blended, the total content may be, for example, 9% by mass or less, preferably 7% by mass or less, more preferably 5% by mass or less, and even more preferably 4% by mass or less, relative to the total mass of the composition.

[0117] Examples of the antioxidant include phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, etc. These antioxidants may be used alone or in combination of two or more.

[0118] Examples of the phenolic antioxidant include acrylate compounds such as 2-t-butyl-6-(3-t-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate and 2,4-di-t-amyl-6-(1-(3,5-di-t-amyl-2-hydroxyphenyl)ethyl)phenyl acrylate, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, octadecyl-3-(3,5-)di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylene-bis( 4-methyl-6-t-butylphenol), 4,4'-butylidene-bis(4-methyl-6-t-butylphenol), 4,4'-butylidene-bis(6-t-butyl-m-cresol), ethylene bis(oxyethylene)bis(3-(5-t-butyl-4-hydroxy-m-tolyl)propionate, 4,4'-thiobis(3-methyl-6-t-butylphenol), bis(3-cyclohexyl-2-hydroxy-5-methylphenyl)methane, 3,9-bis(2-(3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyl) 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis(methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate)methane, triethylene glycol bis(3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate), or or hexamethylenebis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), alkyl-substituted phenolic compounds such as 6-(4-hydroxy-3,5-di-t-butylanilino)-2,4-bis-octylthio-1,3,5-triazine, 6-(4-hydroxy-3,5-dimethylanilino)-2,4-bis-octylthio-1,3,5-triazine, 6-(4-hydroxy-3-methyl-5-t-butylanilino)-2,4-bis-octylthio-1,3,5-triazine, or 2-octylthio-4,6-bis-(3,Examples include triazine group-containing phenolic compounds such as 5-di-t-butyl-4-oxyanilino)-1,3,5-triazine.

[0119] Examples of phosphorus-based antioxidants include triphenyl phosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite, tris(nonylphenyl) phosphite, tris(dinonylphenyl) phosphite, tris(2-t-butyl-4-methylphenyl) phosphite, tris(cyclohexylphenyl) phosphite, 2,2-methylenebis(4,6-di-t-butylphenyl)octyl phosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and Examples of the phosphate include monophosphite compounds such as 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene, and diphosphite compounds such as 4,4'-butylidene-bis(3-methyl-6-t-butylphenyl-di-tridecyl phosphite), 4,4'-isopropylidene-bis(phenyl-di-alkyl(C12 to C15) phosphite), 4,4'-isopropylidene-bis(diphenyl monoalkyl(C12 to C15) phosphite), 1,1,3-tris(2-methyl-4-di-tridecyl phosphite-5-t-butylphenyl)butane, and tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene phosphite. Among these, monophosphite compounds are preferred.

[0120] Examples of sulfur-based antioxidants include dilauryl 3,3'-thiodipropionate, distearyl 3,3'-thiodipropionate, laurylstearyl 3,3'-thiodipropionate, pentaerythritol-tetrakis-(β-lauryl-thiopropionate), 3,9-bis(2-dodecylthioethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, and the like.

[0121] The amount of the antioxidant to be added is preferably 0 to 5 parts by mass, more preferably 0.001 to 5 parts by mass, and even more preferably 0.01 to 1 part by mass, per 100 parts by mass of the acetalized product (A).

[0122] Examples of ultraviolet absorbers include 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α'-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole, and 2-(3,5-di-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole. benzotriazole-based ultraviolet absorbers such as 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, or 2-(2-hydroxy-5-t-octylphenyl)benzotriazole; and benzoate-based ultraviolet absorbers such as 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate or hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate.

[0123] The content of the ultraviolet absorber may be preferably 0 to 50,000 ppm, more preferably 10 to 50,000 ppm, and even more preferably 100 to 10,000 ppm by mass relative to the acetalized product (A).

[0124] Examples of the light stabilizer include hindered amine compounds such as 2,2,6,6-tetramethyl-4-piperidyl benzoate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)-2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonate, 4-(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy)-1-(2-(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy)ethyl)-2,2,6,6-tetramethylpiperidine, and bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidine) sebacate.

[0125] Examples of the plasticizer include dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, phosphate ester, triethylene glycol-di-2-ethylhexanoate, tetraethylene glycol-di-2-ethylhexanoate, di-(2-butoxyethyl)-adipate (DBEA), di-(2-butoxyethyl)-sebacate (DBES), di-(2-butoxyethyl)-azelate, di-(2-butoxyethyl)-glutaric acid ester, di-(2-butoxyethoxyethyl)-adipate (DBEEA), di-(2-butoxyethoxyethyl)-sebacate (DBEES), di-(2-butoxyethoxyethyl)-azelate, di Examples of plasticizers include di-(2-butoxyethoxyethyl)-glutaric acid ester, di-(2-hexoxyethyl)-adipate, di-(2-hexoxyethyl)-sebacic acid ester, di-(2-hexoxyethyl)-azelaic acid ester, di-(2-hexoxyethyl)-glutaric acid ester, di-(2-hexoxyethoxyethyl)-adipate, di-(2-hexoxyethoxyethyl)-sebacic acid ester, di-(2-hexoxyethoxyethyl)-azelaic acid ester, di-(2-hexoxyethoxyethyl)-glutaric acid ester, di-(2-butoxyethyl)-phthalic acid ester and / or di-(2-butoxyethoxyethyl)-phthalic acid ester, and polypropylene glycol (PPG). Among these plasticizers, plasticizers having a sum of the number of carbon atoms and the number of oxygen atoms constituting the molecule of 28 or more are preferred. Examples of such plasticizers include triethylene glycol-di-2-ethylhexanoate, tetraethylene glycol-di-2-ethylhexanoate, di-(2-butoxyethyl)-adipate (DBEA), di-(2-butoxyethoxyethyl)-adipate, di-(2-butoxyethoxyethyl)-sebacate, polypropylene glycol (PPG: average molecular weight 400), etc. These plasticizers may be used alone or in combination of two or more.

[0126] Examples of heat stabilizers include hydrotalcite compounds, hindered phenol-based heat stabilizers, hindered amine-based heat stabilizers, and metal salts of higher aliphatic carboxylic acids (e.g., calcium stearate, magnesium stearate, etc.). Examples of antistatic agents include pentaerythritol monostearate, sorbitan monopalmitate, sulfated polyolefins, polyethylene oxide, carbowax, etc. 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, asbestos, ballastonite, and calcium silicate.

[0127] Examples of the crosslinking aid include polyfunctional allyl compounds and polyfunctional (meth)acrylic compounds. Specific examples include triallyl cyanurate (TAC), triallyl isocyanurate (TAIC), pentaerythritol tetramethacrylate (PETMA), glutaraldehyde (GA), ethylene glycol dimethacrylate (EGDMA), diallyl maleate (DAM), dipropargyl maleate (DPM), dipropargyl monoallyl cyanurate (DPMAC), trimethylolpropane triacrylate (TMPTAT), tetraethylene glycol diacrylate (TEGDA), 1,6-hexaglycol diacrylate, tetramethylolmethane tetraacrylate, dipropargyl succinate, diallyl fumarate, and diallyl phthalate. Among these, triallyl cyanurate and triallyl isocyanurate are particularly preferred.

[0128] In one embodiment of the present invention, the melt flow rate of the composition of the present invention, measured in accordance with JIS K7210:2014 under conditions of 190°C and 2.16 kg, may be preferably 1 to 30 g / 10 min, more preferably 2 to 20 g / 10 min, even more preferably 3 to 10 g / 10 min, and particularly preferably 2.5 to 9 g / 10 min, from the viewpoint of easily suppressing deterioration due to heat during molding processing.

[0129] In one embodiment of the present invention, the oxygen transmission rate of the composition of the present invention at 20°C and 65% RH is preferably 150 cc 20 μm / m ２ · day · atm or less, more preferably 120cc · 20μm / m ２ · day · atm or less, more preferably 100cc · 20μm / m ２ · day · atm or less, even more preferably 75cc · 20μm / m ２ · day · atm or less, particularly preferably 30 cc · 20 μm / m ２ The lower limit of the oxygen transmission rate is not particularly limited, and is, for example, 0 cc·20 μm / m ２ The oxygen transmission rate may be 1 / 2 day atm or more. The oxygen transmission rate can be adjusted by appropriately adjusting the blending ratio of the acetalized product (A) and the resin (B) in the composition. The oxygen transmission rate can be measured in the same manner as the oxygen transmission rate of the acetalized product of the present invention at 20°C and 65% RH.

[0130] The composition of the present invention has a tensile modulus of preferably 2000 MPa or less, more preferably 1900 MPa or less, even more preferably 1800 MPa or less, still more preferably 1700 MPa or less, particularly preferably 1600 MPa or less, and even more particularly preferably 1500 MPa or less, as measured by tensile strength and elongation at 23°C and 50% RH. The lower limit of the tensile modulus is not particularly limited, but is preferably 10 MPa or more, more preferably 100 MPa or more, and even more preferably 1000 MPa or more. The composition of the present invention has a tensile breaking elongation of preferably 150% or more, more preferably 170% or more, even more preferably 180% or more, still more preferably 200% or more, particularly preferably 250% or more, and even more particularly preferably 300% or more, as measured by tensile strength and elongation at 23°C and 50% RH. The upper limit of the tensile breaking elongation is not particularly limited, but is preferably 1000% or less, more preferably 700% or less, and even more preferably 500% or less. By using such a composition, a flexible film or molded product can be obtained, and these can be easily processed by stretching or thermoforming. The tensile modulus and tensile elongation at break can be adjusted by appropriately adjusting the blending ratio of the acetalized product (A) and the resin (B) in the composition. The tensile modulus and tensile elongation at break can be measured in the same manner as the tensile modulus and tensile elongation at break of the acetalized product (A) at 23°C and 50% RH.

[0131] In the composition of the present invention, the melting peak temperature Tm (°C) measured in accordance with JIS K7121:2012 is preferably 136°C or higher, more preferably 138°C or higher, even more preferably 140°C or higher, still more preferably 142°C or higher, particularly preferably 145°C or higher, and is preferably 190°C or lower, more preferably 185°C or lower, even more preferably 183°C or lower, particularly preferably 165°C or lower. When the melting peak temperature Tm is above the lower limit, heat resistance such as retort resistance is easily improved, and when it is below the upper limit, transparency and moldability are easily improved. The melting peak temperature can be adjusted by appropriately adjusting the blending ratio of the acetalized product (A) and the resin (B) in the composition. The melting peak temperature can be measured in the same manner as the melting peak temperature of the acetalized product (A).

[0132] In a preferred embodiment of the present invention, the composition of the present invention exhibits a low oxygen transmission rate, a low tensile modulus, a high tensile elongation at break, and a high melting peak temperature, as described above. Furthermore, in a preferred embodiment of the present invention, a resin film obtained from the composition of the present invention exhibits values ​​similar to those of the haze and stretchability of the resin film of the present invention, as described later in the section [Resin Film, Barrier Material, Molded Article]. Therefore, the composition of the present invention can form a resin film that is excellent in all of barrier properties, transparency, stretchability, flexibility, and heat resistance.

[0133] The uses of the acetalized product and the composition of the present invention are not particularly limited, and they can be used in various fields, for example, as barrier materials or molded articles. Because of their low oxygen transmission rate, they are particularly suitable for use as packaging materials for food, cosmetics, medical and chemical products in the form of bags, tubes, cups, pouches, etc., and as laminates with rubber, such as tire inner liners.

[0134] [Resin Film, Barrier Material, Molded Article] The present invention encompasses a resin film comprising one or more layers containing the acetalized product of the present invention. In a preferred embodiment, the resin film comprises one or more layers containing the acetalized product of the present invention. In a preferred embodiment, the layers do not contain any resin other than the acetalized product of the present invention. The present invention also encompasses the resin film further comprising one or more layers containing one or more resins selected from the group consisting of polyolefins, polyamides, polyesters, and polyurethanes. In a preferred embodiment, the resin film comprises one or more layers containing the acetalized product of the present invention and one or more layers containing one or more resins selected from the group consisting of polyolefins, polyamides, polyesters, and polyurethanes. In a preferred embodiment, the additional layers do not contain any resin other than one or more resins selected from the group consisting of polyolefins, polyamides, polyesters, and polyurethanes.

[0135] The present invention also encompasses a resin film comprising one or more layers containing the composition of the present invention. In a preferred embodiment, the resin film comprises one or more layers containing the composition of the present invention. In a preferred embodiment, the layers contain no resins other than the resin contained in the composition of the present invention. The present invention also encompasses the resin film further comprising one or more layers containing one or more resins selected from the group consisting of polyolefins, polyamides, polyesters, and polyurethanes. In a preferred embodiment, the resin film comprises one or more layers containing the composition of the present invention and one or more layers containing one or more resins selected from the group consisting of polyolefins, polyamides, polyesters, and polyurethanes. In a preferred embodiment, the additional layers do not contain any resins other than one or more resins selected from the group consisting of polyolefins, polyamides, polyesters, and polyurethanes.

[0136] When a resin film contains an additional layer other than the layer containing the acetalized product (A) of the present invention or the composition of the present invention, i.e., a multilayer structure, examples of layer configurations include, but are not limited to, Barrier / R, R / Barrier / R, Barrier / Ad / R, Reg / Barrier / R, R / Ad / Barrier / Ad / R, R / Reg / Ad / Barrier / Ad / Reg / R, etc. When a multilayer structure contains multiple Barriers, Rs, and Ads, they may be the same or different Barriers, Rs, and Ads. Each layer may be a single layer or multiple layers. Furthermore, R may contain recovered resin and / or recovered composition. Here, the recovered resin or recovered composition refers to a resin or composition obtained by recovering the resin film, barrier material or molded article of the present invention for the purpose of reuse, and optionally pulverizing it.

[0137] The additional layer containing one or more resins selected from the group consisting of polyolefins, polyamides, polyesters, and polyurethanes may also contain one or more of the various additives described above, if necessary.

[0138] The polyolefin used in the present invention is not particularly limited. Examples include olefin homopolymers and copolymers such as linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, polypropylene, propylene-α-olefin copolymer (α-olefin having 4 to 20 carbon atoms), polybutene, and polypentene. Examples of copolymerization components other than these α-olefins include diolefins, N-vinylcarbazole, vinyl chloride, vinylidene chloride, styrene, acrylonitrile, vinyl ether and other vinyl compounds, unsaturated carboxylic acids such as maleic acid, acrylic acid, methacrylic acid, ethacrylic acid, fumaric acid, and itaconic acid, their esters, their acid anhydrides, and compounds to which hydroxyl groups or epoxy groups have been added. For example, various copolymers can also be used, such as copolymers of graftable monomers and polyolefins, or ionomer resins, which are reaction products of α-olefin / α,β-unsaturated carboxylic acid copolymers and ionic metal compounds. Furthermore, chlorinated polyethylene, chlorinated polypropylene, and the like can also be used as polyolefins. These polyolefins can be used alone or in combination of two or more. Among the above examples, polypropylene, polyethylene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer are particularly preferred.

[0139] Examples of polyamides that can be used in the present invention include polycapramide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid (nylon-9), polyundecaneamide (nylon-11), polylauryl lactam (nylon-12), polyethylene adipamide (nylon-2,6), polytetramethylene adipamide (nylon-4,6), polyhexamethylene adipamide (nylon-6,6), polyhexamethylene sebacamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12), polyoctamethylene adipamide (nylon-8,6), polydecamethylene adipamide (nylon-10,6), polydodecamethylene sebacamide (nylon-12,10), caprolactam / lauryl lactam copolymer (nylon-6 / 12), caprolactam / ω-aminononanoic acid copolymer (nylon-6 / 9), caprolactam / hexamethylene adipamide copolymer (nylon-6 / 6,6), lauryllactam / hexamethylene adipamide copolymer (nylon-12 / 6,6), hexamethylene adipamide / hexamethylene sebacamide copolymer (nylon-6,6 / 6,10), ethylene adipamide / hexamethylene adipamide copolymer (nylon-2,6 / 6,6), caprolactam / hexamethylene adipamide / hexamethylene sebacamide copolymer (nylon-6 / 6,6 / 6,10), polyhexamethylene isophthalamide, polyhexamethylene terephthalamide, hexamethylene isophthalamide / terephthalamide copolymer, and the like. These polyamides can be used alone or in combination of two or more. Among the above examples, polyamides containing a caproamide component (for example, nylon-6, nylon-6,12, nylon-6 / 12, nylon-6 / 6,6, etc.) are preferred.

[0140] The polyester used in the present invention is not particularly limited. Preferred examples include poly(ethylene terephthalate), poly(butylene terephthalate), poly(ethylene terephthalate / isophthalate), and poly(ethylene glycol / cyclohexanedimethanol / terephthalate). Among these, poly(ethylene terephthalate) is particularly preferred. The polyester may also contain, as a copolymerization component, a diol such as ethylene glycol, butylene glycol, cyclohexanedimethanol, neopentyl glycol, or pentanediol, or a dicarboxylic acid such as isophthalic acid, benzophenone dicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenylmethane dicarboxylic acid, propylene bis(phenylcarboxylic acid), diphenyloxide dicarboxylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, or diethylsuccinic acid.

[0141] The polyurethane used in the present invention is not particularly limited, and examples thereof include polyether polyurethane and polyester polyurethane.

[0142] It is also preferable to use an elastomer as the resin contained in the additional layer. Accordingly, in one embodiment of the present invention, the resin film comprises one or more layers containing the acetalized product or composition of the present invention and one or more layers containing an elastomer. In another embodiment of the present invention, the resin film comprises one or more layers containing the acetalized product or composition of the present invention and one or more layers containing an elastomer. In these embodiments, the layer containing the acetalized product or composition of the present invention does not contain any resin other than the acetalized product of the present invention or any resin other than the resin contained in the composition of the present invention, and / or the layer containing the elastomer does not contain any resin other than the elastomer. The elastomer used in the present invention is not particularly limited. Preferred examples include polyurethane elastomers, polystyrene elastomers, polyamide elastomers, polyester elastomers, polyolefin elastomers, and elastomers composed of copolymers of vinyl aromatic compounds and conjugated diene compounds. Of the elastomers listed as examples, it is preferable to use a polyurethane-based elastomer, from the viewpoint of achieving excellent interlayer adhesion between a layer containing the acetalized product of the present invention or a layer containing the composition of the present invention and a layer containing a polyurethane-based elastomer.

[0143] The thickness of each layer in the resin film is preferably 0.5 μm or more, more preferably 1 μm or more, even more preferably 5 μm or more, and is preferably 250 μm or less, more preferably 200 μm or less, even more preferably 150 μm or less, still more preferably 100 μm or less, particularly preferably 60 μm or less, even more particularly preferably 50 μm or less, and even more particularly preferably 30 μm or less. When the resin film has multiple layers, the thicknesses of the multiple layers in the resin film may be the same or different.

[0144] The thickness of the resin film is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more, from the viewpoint of facilitating enhanced barrier properties, and is preferably 1000 μm or less, more preferably 750 μm or less, even more preferably 500 μm or less, still more preferably 250 μm or less, particularly preferably 100 μm or less, still more particularly preferably 50 μm or less, and even more particularly preferably 30 μm or less, from the viewpoint of flexibility.

[0145] The thickness of each layer in the resin film and the thickness of the resin film are measured by a conventionally known method, for example, using a contact or non-contact thickness gauge.

[0146] The resin film of the present invention has excellent transparency. The haze of the resin film of the present invention is preferably 5% or less, more preferably 3% or less, even more preferably 2% or less, still more preferably 1% or less, particularly preferably 0.5% or less, even more particularly preferably 0.3% or less, and even more particularly preferably 0.2% or less. Since the smaller the haze, the higher the transparency of the resin film, the lower limit is not particularly limited and may be, for example, 0.01% or more. The haze of the resin film is measured using a haze meter in accordance with JIS K7136:2000.

[0147] The resin film of the present invention has excellent stretchability. Therefore, it can be suitably used as a stretched film, particularly as a stretched film stretched at least uniaxially by two times or more. Furthermore, the stretched film can be suitably used as a heat-shrinkable film. The stretchability can be evaluated, for example, by the method described in the Examples below.

[0148] In a preferred embodiment of the present invention, the resin film of the present invention exhibits the same oxygen transmission rate, tensile modulus, tensile elongation at break and melting peak temperature as the acetalized product or composition of the present invention described above in the sections [Acetalized product of ethylene-vinyl alcohol copolymer] and [Composition].

[0149] The resin film of the present invention is excellent in all of barrier properties, transparency, stretchability, flexibility and heat resistance, and therefore the barrier material and molded article made from the resin film of the present invention can also have such excellent physical properties.

[0150] The present invention also includes a barrier material made from the resin film of the present invention and a molded article made from the resin film of the present invention. Examples of the barrier material or molded article include packaging materials, coating materials, cover materials, liners, wallpaper, decorative panels, partition panels, films, heat-shrinkable films (skin pack films, etc.), stretched films, flexible films, flexible packaging materials, containers, bags, bottles, cups, trays, pouches, pipes, hoses, tubes, balloons, irregularly shaped articles, tire inner liners, etc.

[0151] [Method for producing resin film, barrier material, or molded article] The method for producing the resin film, barrier material, or molded article of the present invention is not particularly limited, and the acetalized product of the present invention or the composition of the present invention may be molded into a film or various molded article shapes by known methods such as extrusion molding, press molding, blow molding, injection molding, and solution casting. The resin film, barrier material, or molded article of the present invention can be recovered for reuse, and optionally pulverized and molded again. The resin film can also be uniaxially or biaxially stretched, or subjected to secondary processing such as thermoforming.

[0152] Extrusion molding is a preferred method for producing resin films. In this method, the acetalized product or composition of the present invention is fed into an extruder, kneaded, and melted. The resulting molten mixture is then extruded through a die and taken up by a take-up machine to form a film. The temperature of the resin or composition during extrusion can be selected depending on the composition of the resin or composition, and is, for example, 140 to 270°C, preferably 170 to 250°C, more preferably 180 to 240°C, and even more preferably 190 to 220°C. When the resin or composition temperature during extrusion is below the above-mentioned upper limit, decomposition of the acetalized product or composition is suppressed, making it less likely to become discolored. When the resin or composition temperature during extrusion is above the above-mentioned lower limit, the acetalized product or composition is completely melted, making it easier to obtain a resin film with good appearance and to suppress the generation of volatile substances. In order to efficiently remove the volatile substances, it is preferable to remove them through a vent port of the extruder by reducing the pressure.

[0153] The composition of the present invention in the resin film, barrier material, and molded article of the present invention can be crosslinked to an extent that does not impair the effects of the present invention, in order to improve barrier properties and shape retention under high temperature and high humidity conditions, or to improve shrinkage when used in applications such as heat-shrinkable films. In this case, the composition of the present invention usually contains a crosslinking aid. The method for imparting the crosslinked structure is not particularly limited, but a preferred method is a method of irradiating with energy rays. Examples of energy rays include ionizing radiation such as ultraviolet rays, electron beams, X-rays, α-rays, and γ-rays, and preferably electron beams.

[0154] Regarding the electron beam irradiation method, there is a method in which, after primary processing such as extrusion molding, a resin film, a barrier material, or a molded article is introduced into an electron beam irradiation device and irradiated with electron beams. The dose of the electron beam is not particularly limited, but is preferably 1 to 40 Mrad, more preferably 2 to 30 Mrad. When the dose of the electron beam irradiated is equal to or greater than the lower limit, crosslinking tends to proceed sufficiently. On the other hand, when the dose of the electron beam irradiated is equal to or less than the upper limit, deterioration of the molded article tends to be prevented.

[0155] For molded articles that require secondary processing such as (uniaxial or biaxial) stretching or thermoforming after the primary processing, it is preferable to carry out electron beam irradiation between the primary processing and the secondary processing.

[0156] Usable electron beams are generally electron beams having an energy of 150 to 10,000 KeV emitted from various electron beam accelerators such as Cotcroft-Watson type, Van de Graaff type, resonant transformer type, insulating core transformer type, linear accelerator, dynamitron type, and high frequency cyclotron, but are not limited thereto.

[0157] Examples of methods for producing a multilayer resin film, barrier material, or molded article include melt-extruding a film of the acetalized product or composition of the present invention with another resin or composition; conversely, melt-extruding the acetalized product or composition of the present invention with a film of another resin or composition; co-extrusion molding of the acetalized product or composition of the present invention with another resin or composition; and laminating a film of the acetalized product or composition of the present invention with a film of another resin or composition, optionally using a known adhesive. Among these, co-extrusion molding is preferred. The co-extrusion molding method is not particularly limited. Suitable examples include the multi-manifold method, the feed block method, and the multi-slot die method. Such molding methods can be used to mold multilayer films, multilayer sheets, multilayer pipes, multilayer hoses, and multilayer profiled articles. Multilayer films or multilayer bottles can also be produced by co-extrusion inflation molding, co-extrusion blow molding, and the like. Furthermore, molded articles having desired shapes can be produced by subjecting multilayer resin films or molded articles to secondary processing. Examples of secondary processing include uniaxial or biaxial stretching or heat treatment, rolling, vacuum forming, pressure forming, vacuum pressure forming, stretch blow molding, blow molding, and the like.

[0158] When laminating a film made of the acetalized product or composition of the present invention with a film made of another resin or composition, examples of known adhesives that may be used include organic titanium compounds, isocyanate compounds, polyester compounds, and carboxylic acid-modified polyolefins, with carboxylic acid-modified polyolefins being preferred.

[0159] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0160] The analytical methods and measurement methods for the physical properties of the ethylene-vinyl alcohol copolymer (EVOH) used as a raw material and the acetalized products of the ethylene-vinyl alcohol copolymer obtained in the examples and comparative examples, as well as the evaluation methods for the resin films, are shown below.

[0161] <Content of Each Monomer Unit and Acetalization Degree> The ethylene-vinyl alcohol copolymers used as raw materials in the Examples and Comparative Examples, and the acetalized products of the ethylene-vinyl alcohol copolymers obtained in the Examples and Comparative Examples, were analyzed for the contents (unit: mol %) of ethylene units, vinyl alcohol units, and acetal units, which are acetalized vinyl alcohol units, in the ethylene-vinyl alcohol copolymers and their acetalized products, as well as the acetalization degree, as described below.

[0162] Ethylene-vinyl alcohol copolymer was dissolved in dimethyl sulfoxide (DMSO) at 120°C, and the resulting DMSO solution was cooled to room temperature. N,N-dimethyl-4-aminopyridine and acetic anhydride were then added to the DMSO solution, and the mixture was stirred for 1 hour to allow the reaction to proceed. The copolymer was reprecipitated from the resulting reaction solution using ion-exchanged water and acetone, washed, and then dried to obtain an ethylene-vinyl acetate copolymer. A solution of the resulting ethylene-vinyl acetate copolymer in deuterated dimethyl sulfoxide (DMSO-d6) was analyzed using a 400 MHz proton NMR analyzer with 256 integrations. In the resulting spectrum, the content (n) of ethylene units relative to the total monomer units constituting the ethylene-vinyl alcohol copolymer was calculated from the intensity ratio of the methine proton peaks (peaks between 1.1 and 1.9 ppm) derived from ethylene units and vinyl acetate units in the ethylene-vinyl acetate copolymer to the terminal methyl proton peak (peak at 2.0 ppm) derived from vinyl acetate units. Since ethylene units are not affected by the acetalization reaction, the content (n) of ethylene units in an ethylene-vinyl alcohol copolymer is equal to the content (n) of ethylene units relative to all monomer units constituting the acetalized EVOH obtained after acetalization of the ethylene-vinyl alcohol copolymer. The content (l) of vinyl alcohol units, the content (m) of vinyl acetate units, and the content (k) of acetal units relative to all monomer units constituting the acetalized EVOH were determined by the following method. A DMSO-d6 solution of the acetalized EVOH was measured using a 400 MHz proton NMR spectrometer with an accumulation count of 256. From the obtained spectrum, the content of each monomer unit was calculated using the intensity ratio of the peaks of methine protons derived from ethylene units, vinyl alcohol units, and vinyl acetate units (peaks at 1.0 to 1.8 ppm) to the peak of terminal methyl protons derived from acetal units (peaks at 0.8 to 1.0 ppm), as well as the content (n) of ethylene units in the ethylene-vinyl alcohol copolymer.

[0163] The degree of acetalization of the acetalized EVOH was calculated using the vinyl alcohol unit content (l), vinyl ester unit content (m), and acetal unit content (k) calculated above according to the following formula: Acetalization degree (mol %) = {k / (k + l + m)} × 100

[0164] <Median Pore Diameter and Pore Surface Area> The EVOH porous bodies obtained in each of the Production Examples described below or the EVOH acetalized products obtained in the Examples and Comparative Examples were freeze-dried at -80°C. 0.5 g of the resulting EVOH porous bodies were weighed into a standard 5 cc powder cell (stem volume: 0.4 cc), and the median diameter and pore surface area of ​​pores with diameters in the range of 0.005 to 100 μm were measured using a pore distribution analyzer (Micromeritics, Autopore V9620) under an initial pressure of 2.6 kPa. The median pore diameter is the median diameter (d50) for all pores with diameters in the range of 0.005 to 100 μm in the log differential pore volume distribution. The mercury parameters were a mercury contact angle of 130 degrees and a mercury surface tension of 485 dyn / cm.

[0165] <Average particle size> The average particle size of the measurement sample (freeze-dried EVOH pellets) was measured using a CAMSIZER X2 from Verder Scientific for 100 g of the ethylene-vinyl alcohol copolymers obtained in Production Examples 1 to 6 described below. The particle size (Q3 50.0%) at which the cumulative particle size distribution from the small particle size side of the circle-equivalent particle size calculated by dynamic image analysis in accordance with ISO 13322-2 (2006) accounts for 50% (by volume) was defined as the average particle size.

[0166] <Melt Flow Rate (MFR)> The melt flow rates of the ethylene-vinyl alcohol copolymers used as raw materials in the Examples and Comparative Examples, and the acetalized products of the ethylene-vinyl alcohol copolymers obtained in the Examples and Comparative Examples, were measured at 190°C and under a load of 2.16 kg in accordance with JIS K7210:2014.

[0167] <Symmetry coefficient (W ０．０５ｈThe symmetry coefficients of the acetalized products obtained in the examples and comparative examples were determined by reversed-phase partition gradient high performance liquid chromatography (HPLC) analysis using a water-ethanol eluent under the following conditions in accordance with JIS K 0124:2011. ０．０５ｈ " represents the peak width at a height (5% peak height position) that is 1 / 20 of the peak height from the baseline of the measured peak obtained by HPLC analysis, and "f" represents the distance on the rising side of the peak when the peak width at the 5% peak height position is bisected by a perpendicular line including the peak apex. (Measurement conditions for HPLC analysis) Sample concentration: 1.5 mg / 1 g Sample solvent: EtOH (99.5%) / ion-exchanged water = 9 / 1 wt% mixed solvent Injection volume: 20 μL Detector: Varian 380-LC, EVAP 80°C (pre-stage heating), NEB 50°C (second-stage heating), Gas 1.5 (SLM), data acquisition interval 1000 ms, filter 1 μm ODS silica column: Shimadzu Corporation "Shinpack G-ODS (octadecyl group-modified spherical fully porous silica gel, inner diameter 4 mm × length 10 mm, particle size 5 μm)" Column temperature: 45°C Flow rate: total flow rate 0.4 mL / min (Procedure for HPLC analysis) Water was used as mobile phase A, and ethanol (99.5%) was used as mobile phase B. Before the sample is injected, the inside of the HPLC system column is filled with a mixed solvent of mobile phase A and mobile phase B in a volume ratio of 95 / 5. The sample is injected in this state. The solvent is then allowed to flow under the following conditions: 0-5 minutes (B concentration: constant at 5%) 5-25 minutes (B concentration: 5-100%) 25-30 minutes (B concentration: constant at 100%) 30-31 minutes (B concentration: 100-5%) 31-55 minutes (B concentration: constant at 5%)

[0168] <Tm / Tg (K / K) and Tm (°C)> The acetalized products obtained in the Examples and Comparative Examples were melted by heating from 25°C to 230°C at a heating rate of 10°C / min using a DSC (TGA / DSC1 Star System, manufactured by Mettler Toledo), cooled from 230°C to -30°C at a heating rate of 10°C / min, and then heated again from -30°C to 230°C at a heating rate of 10°C / min. The melting peak temperature Tm (°C) and midpoint glass transition temperature Tg (°C) were measured in accordance with JIS K7121:2012. The obtained values ​​were each converted into Kelvin (K) units to calculate Tm / Tg (K / K). Similarly, the melting peak temperature Tm (°C) of the compositions obtained in the Examples and Comparative Examples was measured.

[0169] <Oxygen Transmission Rate at 20°C and 65% RH> The resin films obtained in the examples and comparative examples were heat-treated at 20°C below their melting point for 10 minutes. Two sheets of each resin film were conditioned at 20°C and 65% RH for five days. Next, using a MOCON OX-TRAN2 / 20 model manufactured by Modern Controls, the oxygen transmission rates were measured in accordance with JIS K7126 (constant pressure method) under conditions of 20°C and 65% RH, and the average values ​​were calculated.

[0170] <Crystalline Melting Heat ΔH> ΔH was measured in accordance with JIS K7121: 2012. More specifically, the acetalized products obtained in the examples and comparative examples were heated from 25°C to 140°C at a heating rate of 10°C / min, held at 140°C for 30 minutes, cooled from 140°C to -30°C at a heating rate of 4°C / min, and then heated again from -30°C to 200°C at a heating rate of 10°C / min, and ΔH was determined using DSC.

[0171] <{ΔH×Tm×amount of vinyl alcohol unit / 100} / (oxygen transmission rate at 20°C, 65% RH)> For the acetalized products obtained in the examples and comparative examples, {ΔH×Tm×amount of vinyl alcohol unit / 100} / (oxygen transmission rate at 20°C, 65% RH) was calculated using the ΔH, Tm, amount of vinyl alcohol unit, and oxygen transmission rate at 20°C, 65% RH determined as described above.

[0172] <Film Formability> The acetalized products and compositions obtained in the Examples and Comparative Examples were extruded into films using a film-forming machine consisting of a 40φ extruder (PLABOR GT-40-A manufactured by the Plastics Engineering Research Institute) and a T-die under the following extrusion conditions to obtain a single-layer resin film having a thickness of 20 μm. Type: Single-screw extruder (non-vent type), L / D: 24, Bore: 40 mmφ, Screw: Single-thread full-flight type, surface-nitrided steel, Screw rotation speed: 40 rpm, Die: 550 mm wide coat hanger die, Lip gap: 0.3 mm, Cylinder and die temperature settings: C1 / C2 / C3 / adapter / die = 180 / 200 / 210 / 210 / 210 (°C). The film formation stability was observed and evaluated according to the following criteria, which served as an index of film formability. (Evaluation criteria for film formability) A: Continuous film formation was possible without any problems, and a resin film with good appearance was obtained. B: Problems such as breakage or loosening occurred at some of the edges of the resin film, but continuous film production was possible and a resin film with relatively good appearance was obtained. C: Problems such as breakage and / or loosening occurred in the resin film, making continuous film production impossible and not allowing a resin film with good appearance to be obtained.

[0173] <Stretchability> The resin films obtained in the examples and comparative examples were set in a pantograph-type biaxial stretching device manufactured by Toyo Seiki Seisaku-sha, and subjected to simultaneous biaxial stretching at a stretching ratio of 2 x 2 at 60°C. The appearance of the film after stretching was evaluated according to the following evaluation criteria. (Evaluation criteria for stretchability) A: No unevenness or local thickness deviation. B: Significant unevenness and large local thickness deviation. C: The film was torn.

[0174] <Tensile Breaking Elongation and Tensile Modulus at 23°C and 50% RH> The resin films obtained in the examples and comparative examples were conditioned at 23°C and 50% RH for 7 days, and then five 15 mm wide rectangular test pieces were prepared for each resin film. The test pieces were set in an autograph AGS-H manufactured by Shimadzu Corporation, and a tensile test was performed under conditions of a chuck distance of 50 mm and a tensile speed of 500 mm / min to determine the tensile breaking elongation and tensile modulus, and the average values ​​for each were calculated.

[0175] <Transparency (Haze of Resin Film)> Test pieces measuring 20 mm long x 5 mm wide were cut out from the resin films obtained in the Examples and Comparative Examples. The haze of the obtained test pieces was measured using a haze meter (SH7000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7136:2000.

[0176] In the examples and comparative examples, pellet-shaped ethylene vinyl alcohol copolymers (EVOH1 to EVOH6) produced by the following methods were used as raw materials.

[0177] Production Example 1 An EVOH solution containing 100 parts by mass of EVOH having an ethylene unit content of 44 mol% and a degree of saponification of 99.98 mol%, 60 parts by mass of methanol, and 40 parts by mass of water was continuously fed into a 10-plate tower with a tower diameter of 0.3 m from the top tray. Steam was blown into the bottom tray to countercurrently contact the EVOH solution with the steam. The temperature inside the tower was 130°C, and the pressure inside the tower was 0.3 MPa. The water-containing EVOH obtained by countercurrently contacting the steam was withdrawn from the bottom of the tower. The temperature of the obtained water-containing EVOH was 120°C, and the water content was 52.4% by mass. The methanol content was 0.02% by mass. The water-containing EVOH was fed into a twin-screw extruder with a back slit at a rate of 42 kg / hr and extruded through a die with 8 holes and a hole diameter of 3.0 mm attached to the tip of the extruder under the following conditions. The extruded molten material was cut with a two-blade hot cutter at a distance of 0.05 mm from the die to obtain flat spherical pellets of EVOH porous material. The flow rate of the cutter circulating water was 300 L / min, and the cutter blade rotation speed was 3000 rpm. The resin temperature (outlet) at this time was 95°C, and the water content was 34% by mass. <Twin-screw extruder conditions> L / D: 14, Diameter: 30 mm, Screw: Full flight, Rotation speed: 300 rpm, Cylinder temperature: 90°C, Die temperature: 120°C. The obtained EVOH porous material was washed with water at 50°C until the sodium acetate content was 0.002% by mass or less in terms of sodium, and the wash water was filtered off to obtain flat spherical pellets of ethylene-vinyl alcohol copolymer porous material (EVOH1). The obtained EVOH1 was flat spherical pellets with an average particle diameter of 3.2 mm. The pellets of EVOH1 had pores with diameters of 0.003 μm to 100 μm, and the median pore size was 0.07 μm. The median pore size, pore surface area, and average particle size of the obtained EVOH1 are shown in Table 1.

[0178] Production Example 2 Pellet-shaped porous ethylene-vinyl alcohol copolymer (EVOH2) was obtained in the same manner as Production Example 1, except that the ethylene content was 32 mol%. The obtained EVOH2 pellets were flattened spheres with an average particle diameter of 3.2 mm. The EVOH2 pellets had pores with diameters of 0.003 μm to 100 μm, and the median pore diameter was 0.11 μm. The median pore diameter, pore surface area, and average particle diameter of the obtained EVOH2 are shown in Table 1.

[0179] <Production Example 3> The ethylene-vinyl alcohol copolymer (EVOH1) obtained in Production Example 1 was fed into a twin-screw extruder and pelletized at a resin temperature of 100°C at the discharge port. The feed rate of EVOH1 per unit time was 10 kg / hr. The specifications of the twin-screw extruder are shown below. <Twin-screw extruder conditions> L / D: 45.5, Diameter: 30 mmΦ, Screw: Co-rotating fully intermeshing type, Rotation speed: 300 rpm, Die diameter: 3.0 mmΦ, Number of die holes: 5. The resulting pellets were dried at 100°C for 15 hours using a fluidized bed dryer, and then dried at 100°C for 15 hours using a static dryer to obtain pelletized ethylene-vinyl alcohol copolymer (EVOH3). The resulting EVOH3 pellets were spherical with an average particle diameter of 2.9 mm. Observation under an electron microscope revealed that EVOH3 did not contain pores. The average particle size of the obtained EVOH3 is shown in Table 1.

[0180] Production Example 4 Pellets of a porous ethylene-vinyl alcohol copolymer (EVOH4) were obtained in the same manner as in Production Example 1, except that the ethylene content was 27 mol%. The obtained EVOH4 pellets were flattened spheres with an average particle diameter of 3.2 mm. The EVOH4 pellets had pores with diameters of 0.003 μm to 100 μm, and the median pore diameter was 0.11 μm. The median pore diameter, pore surface area, and average particle diameter of the obtained EVOH4 are shown in Table 1.

[0181] Production Example 5 Pellets of a porous ethylene-vinyl alcohol copolymer (EVOH5) were obtained in the same manner as in Production Example 1, except that the ethylene content was 15 mol%. The obtained EVOH5 pellets were flattened spheres with an average particle diameter of 3.2 mm. The EVOH5 pellets had pores with diameters of 0.003 μm to 100 μm, and the median pore diameter was 0.05 μm. The median pore diameter, pore surface area, and average particle diameter of the obtained EVOH5 are shown in Table 1.

[0182] <Production Example 6> The ethylene vinyl alcohol copolymer (EVOH3) obtained in Production Example 3 was pulverized using a Supermass Colloider MKCA6-5 at a clearance of 100 μm and a rotation speed of 1800 rpm to obtain EVOH6. The obtained EVOH6 was observed under an electron microscope, and as a result, it was not confirmed that EVOH6 had pores. The average particle size of the obtained EVOH6 is shown in Table 1.

[0183] Example 1 Synthesis of Acetalized Ethylene-Vinyl Alcohol Copolymer 100 parts by mass of the EVOH porous material (EVOH2) obtained in Production Example 2 was dispersed in 377 parts by mass of water, and 29.7 parts by mass of isobutyl aldehyde was added. The resulting dispersion was heated to 60°C with stirring. Stirring was continued for 5 hours, allowing the ethylene-vinyl alcohol copolymer to be impregnated with isobutyl aldehyde. Next, 10 parts by mass of 1M hydrochloric acid was added to the dispersion at 60°C to carry out an acetalization reaction. Two hours after the first addition of hydrochloric acid, 20 parts by mass of 1M hydrochloric acid was added, and the acetalization reaction was carried out for an additional 12 hours (14 hours in total). The acetalized product produced by acetalization was in a solid state. Thereafter, 75 parts by mass of 1M sodium hydroxide was added to the dispersion to neutralize it, thereby terminating the acetalization reaction. The dispersion was stirred for an additional 8 hours at 60°C to neutralize the acetalized product to its solid interior. The neutralized acetalized product was filtered, and 500 parts by mass of ion-exchanged water was added to the acetalized product, followed by stirring at 60°C for 6 hours to wash the acetalized product. The acetalized product was again filtered, and 500 parts by mass of ion-exchanged water was added to the acetalized product, followed by stirring at 60°C for 6 hours to perform a second washing of the acetalized product. The wash water was filtered off, and the product was vacuum dried at 60°C for 8 hours to obtain 113 parts by mass (yield 100%) of pelletized ethylene-vinyl alcohol copolymer acetalized product (A-1). The obtained acetalized EVOH was a porous body having a pore structure similar to that of the raw material EVOH2.

[0184] The acetalized EVOH obtained above was extruded into a film-forming machine consisting of a 40φ extruder (PLABOR GT-40-A manufactured by Plastics Engineering Research Institute) and a T-die under the following extrusion conditions to obtain a single-layer resin film with a thickness of 20 μm: Type: Single-screw extruder (non-vent type), L / D: 24, Diameter: 40 mmφ, Screw: Single-row full-flight type, surface-nitrided steel, Screw rotation speed: 40 rpm, Die: 550 mm wide coat hanger die, Lip gap: 0.3 mm, Cylinder and die temperature settings: C1 / C2 / C3 / adapter / die=180 / 200 / 210 / 210 / 210 (°C). The physical properties of the obtained resin film were evaluated.

[0185] Examples 2 to 7 Acetalized ethylene-vinyl alcohol copolymer pellets (A-2) to (A-7) were obtained in the same manner as in Example 1, except that the type of ethylene-vinyl alcohol copolymer and the acetalization reaction conditions were changed as shown in Table 1. Of the obtained acetalized ethylene-vinyl alcohol copolymers, (A-2) to (A-6) were porous bodies having the same pore structure as the starting ethylene-vinyl alcohol copolymer. Using the obtained acetalized ethylene-vinyl alcohol copolymers, melt-kneaded products and resin films were obtained, respectively, in the same manner as in Example 1.

[0186] Comparative Examples 1, 3, and 4 Acetalized ethylene-vinyl alcohol copolymer pellets (B-1), (B-3), and (B-4) were obtained in the same manner as in Example 1, except that the type of ethylene-vinyl alcohol copolymer and the acetalization reaction conditions were changed as shown in Table 1. Using the obtained acetalized EVOH, melt-kneaded products and resin films were obtained in the same manner as in Example 1.

[0187] Comparative Example 2: 100 parts by mass of the EVOH porous material (EVOH1) obtained in Production Example 1 was dispersed in a mixed solvent of 500 parts by mass of methanol and 50 parts by mass of ion-exchanged water. Next, 40 parts by mass of 1M hydrochloric acid was added, and the temperature of the resulting dispersion was raised to 60°C with stirring to completely dissolve the EVOH1 pellets. 16.7 parts by mass of isobutyraldehyde was added to the resulting solution and mixed to homogeneity, followed by an acetalization reaction at 60°C. After two hours of reaction, the acetalization reaction was terminated by neutralizing the mixture with the addition of 60 parts by mass of 1M sodium hydroxide, yielding a reaction solution containing an acetalized product of ethylene-vinyl alcohol copolymer. 500 parts by mass of methanol was added to the neutralized reaction solution, and the resulting solution was then added dropwise to 2,000 parts by mass of ion-exchanged water to precipitate an acetalized product of ethylene-vinyl alcohol copolymer. The precipitated acetalized product was filtered, dispersed in ion-exchanged water, and stirred at 23°C for 15 minutes for water washing, and the acetalized product was again filtered. This water-washing and filtration procedure was repeated two more times. This washing procedure from precipitation to water washing and filtration constituted one set. Next, the acetalized product was dissolved in 1,000 parts by mass of methanol, and another set of washing was performed. Vacuum drying was carried out at 60°C for 8 hours to obtain an acetalized product of ethylene-vinyl alcohol copolymer (B-2) after washing and vacuum drying. The ethylene unit content of the acetalized product of ethylene-vinyl alcohol copolymer (B-2) was 44 mol%, and the degree of acetalization was 30 mol%. Using the obtained acetalized product of ethylene-vinyl alcohol copolymer (B-2), a melt-kneaded product and a resin film were obtained in the same manner as in Example 1.

[0188] Comparative Example 5 A pellet-shaped acetalized product of ethylene-vinyl alcohol copolymer (B-5) was obtained in the same manner as in Example 1, except that the type of ethylene-vinyl alcohol copolymer and the acetalization reaction conditions were changed as shown in Table 1. The obtained acetalized product of ethylene-vinyl alcohol copolymer was a porous body having the same pore structure as the raw material ethylene-vinyl alcohol copolymer. Using the obtained acetalized product of ethylene-vinyl alcohol copolymer, a melt-kneaded product and a resin film were obtained in the same manner as in Example 1.

[0189] Comparative Examples 6 and 7 Using EVOH1 and EVOH2 obtained in Production Examples 1 and 2, melt-kneaded materials and resin films were obtained in the same manner as in Example 1, respectively.

[0190] <Comparative Example 8> An acetalized product of ethylene-vinyl alcohol copolymer (B-6) was obtained in the same manner as in Comparative Example 2, except that the amount of isobutyraldehyde was changed as shown in Table 1, and a melt-kneaded product and a resin film were obtained.

[0191] According to the methods described above, various physical properties of the resins and resin films obtained in Examples 1 to 7 and Comparative Examples 1 to 8 were evaluated. The results are shown in Table 1.

[0192]

[0193] Example 8 25 parts by mass of acetalized ethylene-vinyl alcohol copolymer (A-1) and 75 parts by mass of ethylene-vinyl alcohol copolymer (EVOH2) were melt-kneaded using a Labo Plastomill at a chamber temperature of 210°C and a rotation speed of 90 rpm for 5 minutes. The contents of the chamber were removed and cooled to obtain a composition. A resin film was obtained using the obtained composition in the same manner as in Example 1.

[0194] Examples 9 to 12 and Comparative Examples 9 to 10 Compositions and resin films were obtained in the same manner as in Example 8, except that the resins used were changed as shown in Table 2.

[0195] According to the methods described above, various physical properties of the compositions and resin films obtained in Examples 8 to 12 and Comparative Examples 9 and 10 were evaluated. The results are shown in Table 2.

[0196]

[0197] As shown in Tables 1 and 2, it was confirmed that the acetalized products and compositions obtained in the Examples provided resin films excellent in all of barrier property, transparency, stretchability, flexibility, and heat resistance. On the other hand, it was confirmed that the resins and compositions obtained in the Comparative Examples provided resin films inferior in one or more of barrier property, transparency, stretchability, flexibility, and heat resistance.

[0198] Thus, the acetalized product and composition of the ethylene-vinyl alcohol copolymer of the present invention can form a resin film that is excellent in all of barrier properties, transparency, stretchability, flexibility and heat resistance.

Claims

1. An acetalized product of an ethylene-vinyl alcohol copolymer, Based on the total monomer units constituting the acetalized product, 20 to 80 mole % ethylene units, and 4 to 76 mol % vinyl alcohol units Including, The degree of acetalization is 3 to 80 mol %, Formula (1): 0.71≦W ０．０５ｈ / 2f≦1.09 (1) [In formula (1), W ０．０５ｈ / 2f represents a symmetry coefficient determined by reversed-phase partition gradient high-performance liquid chromatography analysis using a water-ethanol eluent in accordance with JIS K 0124:2011. and formula (2): 1.20≦Tm / Tg≦1.35 (2) [In formula (2), Tm and Tg represent the melting peak temperature (Kelvin) and the midpoint glass transition temperature (Kelvin), respectively, measured in accordance with JIS K7121:2012.] Fulfilling Oxygen transmission rate at 20℃ and 65% RH is 150cc・20μm / m ２ ・Day・atm or less, Acetal compounds.

2. Formula (3): {ΔH (J / g) × Tm (Kelvin) × vinyl alcohol unit amount (mol%) / 100} / (oxygen transmission rate at 20 ° C. and 65% RH) ≧ 30 (3) The acetalized product according to claim 1 , which satisfies the above.

3. The acetalized product according to claim 1, having a degree of acetalization of 40 mol % or less.

4. The acetalized product according to claim 1, having a melting peak temperature Tm of 136°C or higher as measured in accordance with JIS K7121:2012.

5. The acetalized product according to claim 1, having a tensile modulus of elasticity of 2000 MPa or less at 23°C and 50% RH.

6. (A) an acetal compound according to any one of claims 1 to 5; (B) (B-1) Acetalization products of ethylene-vinyl alcohol copolymers other than (A), (B-2) ethylene-vinyl alcohol copolymer, and (B-3) Resins other than (B-1) and (B-2) One or more resins selected from the group consisting of A composition comprising:

7. (i) preparing a dispersion containing an ethylene-vinyl alcohol copolymer, an aldehyde, and a solvent, and impregnating at least a portion of the aldehyde into the ethylene-vinyl alcohol copolymer; and (ii) After step (i), a step of adding a catalyst to the dispersion to acetalize the ethylene-vinyl alcohol copolymer. Including, The method for producing an acetalized product according to any one of claims 1 to 5, wherein the acetalization is carried out by a solid-liquid reaction.

8. A resin film comprising at least one layer containing the acetalized product according to any one of claims 1 to 5.

9. A resin film comprising at least one layer containing the composition according to claim 6.

10. The resin film according to claim 8, further comprising one or more layers containing one or more resins selected from the group consisting of polyolefins, polyamides, polyesters, and polyurethanes.

11. The resin film according to claim 9, further comprising one or more layers containing one or more resins selected from the group consisting of polyolefins, polyamides, polyesters, and polyurethanes.

12. A barrier material comprising the resin film according to claim 8.

13. A barrier material comprising the resin film described in claim 9.

14. A molded article comprising the resin film according to claim 8.

15. A molded body comprising the resin film described in claim 9.

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