Gas barrier resin compositions, molded articles, films or sheets, packaging materials, industrial films or sheets, thermoformed containers, cup-shaped containers, tray-shaped containers, blow-molded containers, fuel containers, bottle containers, tubes, multilayer pipes, and paper containers

Abstract

The present invention provides: a gas barrier resin composition which uses a starting material derived from biomass and still has high gas barrier properties and high formability equivalent to those of materials derived from fossil fuels; and a molded body, a film or sheet, a packaging material, a film or sheet for industrial uses, a heat molded container, a cup shaped container, a tray shaped container, a blow molded container, a fuel container, a bottle container, a tube, a multilayer pipe and a paper container, each of which uses the above-described gas barrier resin composition. A gas barrier resin composition that contains a saponified ethylene-vinyl ester copolymer, wherein the ethylene and the vinyl ester, which are starting materials of the saponified ethylene-vinyl ester copolymer, are derived from biomass.

Description

[Technical Field]

[0001] The present invention relates to a gas barrier resin composition, a molded article, a film or sheet, a packaging material, an industrial film or sheet, a thermoformed container, a cup-shaped container, a tray-shaped container, a blow-molded container, a fuel container, a bottle container, a tube, a multilayer pipe, and a paper container. [Background technology]

[0002] Gas barrier materials made of resins with excellent gas barrier properties (gas barrier properties) that block gases such as oxygen are widely used in a variety of applications, such as containers, films, sheets, and pipes. Examples of resins known to have excellent gas barrier properties include polyamide, polyester, polyvinylidene chloride, acrylonitrile copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, and saponified ethylene-vinyl ester copolymer. For example, Patent Document 1 describes an invention for a multilayer plastic container having at least one gas barrier resin layer selected from polyamide, polyester, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, fluorine-containing resin, and silicone resin.

[0003] Meanwhile, in recent years, demand for bioplastics made from carbon-neutral biomass-derived raw materials has been increasing in pursuit of a recycling-oriented society. However, it is known that biomass-derived synthetic resins can have inferior performance compared to fossil fuel-derived synthetic resins. For example, Patent Document 2 describes an invention of a resin film that includes a biomass-derived resin layer of a specific composition containing a biomass-derived resin, which is intended to improve upon the insufficient qualities of conventional biomass-derived film materials such as polyolefins, including adhesion, processability, and durability. Patent Document 3 also describes an invention of a laminate film that includes an intermediate layer containing biomass-derived biomass polyethylene, fossil fuel-derived polyethylene, and a propylene-based block copolymer resin, which is intended to improve upon the insufficient qualities of conventional biomass-derived film materials, such as polyolefins, in terms of adhesion, processability, and durability. Patent Document 4 also describes an invention related to a laminate having a layer made of a carbon-neutral polyester resin film using biomass ethylene glycol, which cites a saponified ethylene-vinyl ester copolymer as an example of a gas barrier resin, but which is described as a resin made from fossil fuel-derived raw materials. The laminate of Patent Document 4 is limited as a bioplastic because it contains both biomass-derived resin and fossil fuel-derived resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-137506 [Patent Document 2] International Publication No. 2014 / 065380 [Patent Document 3] International Publication No. 2018 / 163835 [Patent Document 4] Japanese Patent Application Laid-Open No. 2012-096410 Summary of the Invention [Problem to be solved by the invention]

[0005] For gas barrier material applications, commercialization of gas barrier resins synthesized using biomass-derived raw materials is anticipated. However, as mentioned above, biomass-derived synthetic resins may have inferior performance compared to fossil fuel-derived synthetic resins. Therefore, there is concern that replacing conventional fossil fuel-derived gas barrier resins with biomass-derived gas barrier resins will result in a decline in the most important gas barrier properties and moldability. For this reason, there is a need for the development of biomass-derived resins that have excellent gas barrier properties and moldability comparable to those of fossil fuel-derived resins.

[0006] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a gas barrier resin composition which uses a biomass-derived raw material and which has high gas barrier properties and molding processability comparable to those of fossil fuel-derived raw materials, as well as a molded article, film or sheet, packaging material, industrial film or sheet, thermoformed container, cup-shaped container, tray-shaped container, blow-molded container, fuel container, bottle container, tube, multi-layer pipe and paper container which uses this gas barrier resin composition. [Means for solving the problem]

[0007] The present inventors have discovered that, in the case of saponified ethylene-vinyl ester copolymers, which are a type of gas barrier resin, those synthesized using raw materials derived from biomass as monomers have high gas barrier properties and moldability comparable to conventional products of the same structure synthesized using raw materials derived from fossil fuels as monomers, and have thus completed the present invention.

[0008] That is, the present invention provides: [1] A gas barrier resin composition comprising a saponified ethylene-vinyl ester copolymer, wherein the ethylene and vinyl ester that are raw materials for the saponified ethylene-vinyl ester copolymer are derived from biomass; [2] The gas barrier resin composition of [1], wherein the saponified ethylene-vinyl ester copolymer has a bio-based content of more than 99%; [3] The gas barrier resin composition of [1] or [2], which has a bio-based content of more than 99%; [4] The gas barrier resin composition according to any one of [1] to [3], containing a sulfur compound in an amount of more than 0 ppm and not more than 100 ppm in terms of sulfur atoms; [5] The gas barrier resin composition according to [4], wherein the sulfur compound is dimethyl sulfide or dimethyl sulfoxide; [6] The gas barrier resin composition according to any one of [1] to [5], wherein the saponified ethylene-vinyl ester copolymer comprises a saponified ethylene-vinyl ester copolymer (X) and a saponified ethylene-vinyl ester copolymer (Y) having a melting point lower than that of the saponified ethylene-vinyl ester copolymer (X); [7] The gas barrier resin composition according to [6], wherein the mass ratio (X / Y) of the saponified ethylene-vinyl ester copolymer (X) to the saponified ethylene-vinyl ester copolymer (Y) is 60 / 40 or more and 95 / 5 or less; [8] The gas barrier resin composition according to [6] or [7], wherein the difference in melting point (XY) between the saponified ethylene-vinyl ester copolymer (X) and the saponified ethylene-vinyl ester copolymer (Y) is 15°C or more; [9] The gas barrier resin composition according to any one of [1] to [8], which contains a carboxylic acid in an amount of 30 ppm or more and 1000 ppm or less in terms of a carboxylic acid radical;

[10] The gas barrier resin composition according to any one of [1] to [9], containing metal ions in an amount of 1 ppm or more and 1000 ppm or less;

[11] The gas barrier resin composition according to any one of [1] to

[10] , containing a phosphate compound in an amount of 1 ppm or more and 200 ppm or less in terms of phosphorus atoms;

[12] The gas barrier resin composition according to any one of [1] to

[11] , which contains a boron compound in an amount of 5 ppm or more and 5000 ppm or less in terms of boron atoms;

[13] A molded article having a layer formed from the gas barrier resin composition according to any one of [1] to

[12] .

[14] The molded article according to

[13] , further comprising a thermoplastic resin layer;

[15] A film or sheet comprising a shaped body according to

[13] or

[14] ;

[16]

[15] packaging material comprising a film or sheet;

[17] Industrial films or sheets comprising the shaped body of

[13] or

[14] ;

[18] A thermoformed container comprising the molded article according to

[13] or

[14] ;

[19]

[18] A cup-shaped container comprising a thermoformed container;

[20]

[18] Tray-like containers, including thermoformed containers;

[21] A blow-molded container comprising the molding of

[13] or

[14] ;

[22]

[21] a fuel container comprising a blow-molded container;

[23]

[21] A bottle container comprising a blow-molded container;

[24]

[13] or

[14] , comprising a molding;

[25]

[13] or

[14] multilayer pipes;

[26]

[13] or

[14] , a paper container comprising a molding; This is achieved by providing: [Effects of the Invention]

[0009] The present invention can provide a gas barrier resin composition which uses a biomass-derived raw material and yet has high gas barrier properties and molding processability comparable to those of fossil fuel-derived materials, as well as a molded article, film or sheet, packaging material, industrial film or sheet, thermoformed container, cup-shaped container, tray-shaped container, blow-molded container, fuel container, bottle container, tube, multi-layer pipe and paper container which uses this gas barrier resin composition. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic perspective view showing a cup-shaped container according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the cup-shaped container of FIG. [Figure 3] FIG. 3 is a schematic diagram for explaining a method for manufacturing the cup-shaped container of FIG. [Figure 4]4(A) to 4(D) are schematic diagrams for explaining a method for manufacturing the cup-shaped container of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Gas barrier resin composition> The gas barrier resin composition of the present invention contains a saponified ethylene-vinyl ester copolymer (ethylene-vinyl alcohol copolymer; hereinafter, also referred to as "EVOH"), in which the raw materials (raw material monomers) of the EVOH, ethylene and vinyl ester, are biomass-derived (hereinafter, the EVOH contained in the gas barrier resin composition of the present invention, whose raw materials are biomass-derived, is also referred to as "biomass-derived EVOH"). The gas barrier resin composition has an extremely low environmental impact because it uses biomass-derived raw materials. Furthermore, the gas barrier resin composition uses EVOH as the gas barrier resin, and even when synthesized using biomass-derived raw materials, it exhibits high gas barrier properties and moldability equivalent to those of EVOH of the same structure synthesized exclusively from fossil fuel-derived raw materials. Note that "EVOH of the same structure" refers to EVOH that has the same degree of polymerization, the content ratio of each structural unit, the presence or absence of modification, the degree of saponification, etc.

[0012] The biomass-derived origin of ethylene and vinyl esters used as raw materials can be confirmed by measuring their biobased content. The biobased content is an index that indicates the proportion of raw materials derived from biomass. In this specification, it is defined as the biobased content measured by an accelerator mass spectrometer (AMS) using radiocarbon ( 14 The biobased carbon content is determined by measuring the concentration of carbon dioxide (CO₂) and carbon dioxide (C). Specifically, the biobased content can be measured according to the method described in ASTM D6866-18.

[0013] "Biomass" refers to organic resources derived from plants and animals, excluding fossil fuels (fossil resources). Biomass may be organic resources derived from plants.

[0014] The gas barrier resin composition of the present invention is 14 It is also possible to track your products using the concentration of radiocarbon (C). During their activity, organisms absorb radiocarbon ( 14 C) and contains a certain amount, but when activity stops, new 14 C uptake ceases, and the ratio of C to total carbon 14 In addition, when plants fix carbon, a phenomenon called isotope sorting occurs, and the ratio of C to total carbon varies from plant species to plant species. 14 It is known that the ratio of C to total carbon varies. 14 It is known that the ratio of C varies depending on the origin and age, and the ratio of C to total carbon varies depending on the biomass used as raw material. 14 For example, different ratios of C to total carbon can be obtained. 14 By changing the ratio of C to the raw material, the specific total carbon 14 It is possible to obtain EVOH with a ratio of C to the total carbon. 14 By examining the C ratio, it becomes possible to track the EVOH (gas barrier resin composition) manufactured in-house.

[0015] EVOH is used in a wide range of applications, and it is the responsibility of suppliers to supply high-quality products to the market. Furthermore, there is a need for a method to distinguish one company's products from those of other companies for branding purposes. For example, the EVOH used in the gas barrier layer of commercially available packaging containers is formed into the container by thermoforming. However, the heat history during thermoforming can cause the saponified ethylene-vinyl ester copolymer to form a gel that is insoluble in solvents. Therefore, even if attempts are made to recover packaging containers, extract the EVOH used in the container with a solvent, and measure its molecular weight, accurate molecular weight determination is often difficult. Therefore, it is not possible to determine whether a product is made by one company or not simply by analyzing the molded product.

[0016] EVOH is distributed through many channels and is used in films, sheets, containers, and other packaging materials for foods, pharmaceuticals, industrial chemicals, pesticides, and other products. Its barrier properties, heat retention, and contamination resistance make it suitable for applications such as fuel tanks for automobiles and other vehicles, tire tubes, agricultural films, geomembranes, and shoe cushioning. When these materials containing EVOH are discarded, it is difficult to determine the factory and production line from which the resin and its used packaging containers were manufactured. It is also difficult to investigate the quality of a company's products during or after use, or to track their environmental impact and decomposition in the ground after disposal.

[0017] One method of tracking your own products is to add a tracer substance to EVOH. However, adding a tracer can increase costs and reduce the performance of EVOH. 14 Being able to track your own products using the concentration of C) is a very useful effect.

[0018] The gas barrier resin composition of the present invention is a resin composition that has the function of inhibiting gas permeation. The upper limit of the oxygen permeation rate of the gas barrier resin composition of the present invention, measured under conditions of 20°C and 65% RH in accordance with the method described in JIS K 7126-2 (isobaric method; 2006), is 100 mL 20 μm / (m 2 ·day·atm) is preferred, and 50mL·20μm / (m 2 ·day·atm) is more preferable, and 10mL·20μm / (m 2 ·day·atm), 1mL·20μm / (m 2 ·day·atm), or 0.5mL·20μm / (m 2 ·day·atm) is more preferable.

[0019] (Biomass-derived EVOH) The biomass-derived EVOH contained in the gas barrier resin composition of the present invention is an EVOH in which the raw material monomers, ethylene and vinyl ester, are derived from biomass. By including raw materials derived from biomass in the biomass-derived EVOH, the bio-based content of the gas barrier resin composition of the present invention can be increased, thereby reducing the environmental load.

[0020] Biomass-derived EVOH can be obtained by saponifying a copolymer of ethylene and a vinyl ester derived from biomass. The production and saponification of the ethylene-vinyl ester copolymer, which serves as a precursor to biomass-derived EVOH, can be carried out by known methods similar to those used for the production and saponification of conventional ethylene-vinyl ester copolymers derived from fossil fuels. Examples of vinyl esters that can be used include vinyl carboxylates such as vinyl acetate, vinyl formate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl pivalate, and vinyl versatate, with vinyl acetate being preferred.

[0021] Biomass-derived ethylene can be produced by known methods, such as purifying bioethanol from biomass raw materials and then subjecting it to a dehydration reaction. Examples of biomass raw materials that can be used include waste, unused materials, and resource crops, such as cellulosic crops (pulp, kenaf, wheat straw, rice straw, waste paper, papermaking residues, etc.), wood, charcoal, compost, natural rubber, cotton, sugarcane, soybean pulp refuse, oils and fats (rapeseed oil, cottonseed oil, soybean oil, coconut oil, castor oil, etc.), carbohydrate crops (corn, potatoes, wheat, rice, rice husks, rice bran, used rice, cassava, sago palm, etc.), bagasse, buckwheat, soybeans, essential oils (pine oil, orange oil, eucalyptus oil, etc.), pulp black liquor, and vegetable oil cakes.

[0022] The method for producing bioethanol is not particularly limited, and for example, biomass raw materials can be pretreated as needed (compressed hot water treatment, acid treatment, alkali treatment, saccharification treatment using a saccharifying enzyme), followed by yeast fermentation to produce bioethanol, and then the bioethanol can be purified through a distillation process and a dehydration process. When saccharification treatment is performed during bioethanol production, sequential saccharification and fermentation in which saccharification and fermentation are carried out in stages may be used, or parallel saccharification and fermentation in which saccharification and fermentation are carried out simultaneously may be used, but from the perspective of production efficiency, it is preferable to produce bioethanol by parallel saccharification and fermentation.

[0023] Commercially available biomass-derived ethylene may also be used, for example, sugarcane-derived bioethylene manufactured by Braskem SA.

[0024] Examples of biomass-derived vinyl esters include vinyl esters produced using biomass-derived ethylene. Examples of methods for producing biomass-derived vinyl esters include a common industrial method of reacting ethylene, acetic acid, and molecular oxygen using a palladium catalyst. Furthermore, in biomass-derived vinyl esters, the moiety (acyl group) derived from a carboxylic acid such as acetic acid may be derived from biomass or from a fossil fuel. That is, biomass-derived vinyl esters may be produced using biomass-derived ethylene and a carboxylic acid derived from biomass or a fossil fuel. Most of the carboxylic acid-derived moiety in the ethylene-vinyl ester copolymer is eliminated by saponification, and the eliminated carboxylic acid can be reused for synthesis, so there is little impact from the perspective of carbon neutrality.

[0025] The lower limit of the ethylene unit content of the biomass-derived EVOH is preferably 20 mol%, more preferably 23 mol%, and even more preferably 25 mol%. When the ethylene unit content of the biomass-derived EVOH is 20 mol% or more, molding processability, long-run properties, etc. tend to be improved. The upper limit of the ethylene unit content of the biomass-derived EVOH is preferably 60 mol%, more preferably 55 mol%, and even more preferably 50 mol%. When the ethylene unit content of the biomass-derived EVOH is 60 mol% or less, gas barrier properties tend to be better. The ethylene unit content of the EVOH can be determined by nuclear magnetic resonance (NMR) spectroscopy.

[0026] The lower limit of the saponification degree of the biomass-derived EVOH is preferably 90 mol%, more preferably 95 mol%, and even more preferably 99 mol%. When the saponification degree of the biomass-derived EVOH is 90 mol% or more, the gas barrier properties, molding processability, and long-run properties of the gas barrier resin composition of the present invention tend to be better. Furthermore, the upper limit of the saponification degree of the biomass-derived EVOH may be 100 mol%, or may be 99.97 mol% or 99.94 mol%. The saponification degree of the EVOH is 1 The peak area of ​​the hydrogen atoms contained in the vinyl ester structure and the peak area of ​​the hydrogen atoms contained in the vinyl alcohol structure can be measured by H-NMR measurement and calculated.

[0027] The biobased content of biomass-derived EVOH is preferably greater than 99%, more preferably greater than 99.5%, and may be 100%. Since the raw materials may contain some fossil fuel-derived raw materials, the biobased content may be less than 100%, but from the perspective of reducing the environmental impact, the biobased content of biomass-derived EVOH is preferably in the above range.

[0028] The biomass-derived EVOH may contain units derived from monomers other than ethylene, vinyl esters, and saponified products thereof, provided that the object of the present invention is not impaired. When the biomass-derived EVOH contains units derived from the other monomers, the upper limit of the content of the units derived from the other monomers relative to the total structural units of the biomass-derived EVOH is preferably 30 mol%, more preferably 20 mol%, even more preferably 10 mol%, even more preferably 5 mol%, and sometimes even more preferably 1 mol%. Furthermore, when the biomass-derived EVOH contains units derived from the other monomers, the lower limit of the content may be 0.05 mol% or 0.10 mol%. Examples of the other monomers include alkenes such as propylene, butylene, pentene, and hexene; 3-acyloxy-1-propene, 3-acyloxy-1-butene, 4-acyloxy-1-butene, 3,4-diacyloxy-1-butene, 3-acyloxy-4-methyl-1-butene, 4-acyloxy-2-methyl-1-butene, and 4-acyloxy-3-methyl-1-butene. -butene, 3,4-diacyloxy-2-methyl-1-butene, 4-acyloxy-1-pentene, 5-acyloxy-1-pentene, 4,5-diacyloxy-1-pentene, 4-acyloxy-1-hexene, 5-acyloxy-1-hexene, 6-acyloxy-1-hexene, 5,6-diacyloxy-1-hexene, 1,3-diacetoxy-2-methylene Examples of suitable vinyl silane compounds include alkenes having an ester group such as propane or saponified products thereof; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, or the like, or their anhydrides, salts, or mono- or dialkyl esters; nitriles such as acrylonitrile and methacrylonitrile; amides such as acrylamide and methacrylamide; olefin sulfonic acids such as vinyl sulfonic acid, allyl sulfonic acid, and methallylsulfonic acid, or their salts; vinyl silane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(β-methoxyethoxy)silane, and γ-methacryloxypropylmethoxysilane; alkyl vinyl ethers, vinyl ketone, N-vinylpyrrolidone, vinyl chloride, and vinylidene chloride.

[0029] The biomass-derived EVOH may be post-modified by a method such as urethanization, acetalization, cyanoethylation, or oxyalkylenation.

[0030] When the biomass-derived EVOH has a modifying group such as another monomer unit, the biomass-derived EVOH may have a structural unit (modifying group) represented by the following formula (I).

[0031] [ka]

[0032] [In formula (I), X represents a hydrogen atom, a methyl group, or R 2 R represents a group represented by -OH. 1 and R 2 each independently represents a single bond, an alkylene group having 1 to 9 carbon atoms, or an alkyleneoxy group having 1 to 9 carbon atoms, and the alkylene group and the alkyleneoxy group may contain a hydroxyl group, an alkoxy group, or a halogen atom.

[0033] X is preferably a hydrogen atom or R 2 is a group represented by —OH, and more preferably R 2 It is a group represented by -OH.

[0034] R 1 or R 2 The alkylene and alkyleneoxy groups used as R may contain a hydroxyl group, an alkoxy group, or a halogen atom. 1 and R 2 is preferably an alkylene group or alkyleneoxy group having 1 to 5 carbon atoms, and more preferably an alkylene group or alkyleneoxy group having 1 to 3 carbon atoms.

[0035] Specific examples of the structural unit (modifying group) represented by formula (I) include structural units (modifying groups) represented by the following formulae (II), (III), and (IV).

[0036] [ka]

[0037] [In formula (II), R 3 and R 4 each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and the alkyl group may contain a hydroxyl group, an alkoxy group, or a halogen atom.]

[0038] [ka]

[0039] [In formula (III), R 5 has the same meaning as X in formula (I). 6 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and the alkyl group may contain a hydroxyl group, an alkoxy group, or a halogen atom.]

[0040] [ka]

[0041] [In formula (IV), R 7 and R 8 each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, or a hydroxyl group. Some or all of the hydrogen atoms in the alkyl group or cycloalkyl group may be substituted with a hydroxyl group, an alkoxy group, or a halogen atom.

[0042] In the present invention, R in formula (I) 1 is a single bond, and X is a hydroxymethyl group (R 3 , R 4may be a hydrogen atom). Use of biomass-derived EVOH having this structural unit (modifying group) tends to improve secondary processability such as stretchability and thermoformability without significantly deteriorating gas barrier properties. When the biomass-derived EVOH contains the structural unit (modifying group), the lower limit of its content is preferably 0.1 mol%, more preferably 0.4 mol%, and even more preferably 1.0 mol%. On the other hand, from the viewpoint of improving gas barrier properties, the upper limit of the content of the structural unit (modifying group) is preferably 20 mol%, more preferably 10 mol%, even more preferably 8 mol%, and particularly preferably 5 mol%.

[0043] In the present invention, R in formula (I) 1 is a hydroxymethylene group, X is a hydrogen atom (R 5 , R 6 may be a hydrogen atom). Use of biomass-derived EVOH having this structural unit (modifying group) tends to improve secondary processability such as stretchability and thermoformability without significantly deteriorating gas barrier properties. When the biomass-derived EVOH contains the structural unit (modifying group), the lower limit of its content is preferably 0.1 mol%, more preferably 0.4 mol%, and even more preferably 1.0 mol%. On the other hand, from the viewpoint of improving gas barrier properties, the upper limit of the content of the structural unit (modifying group) is preferably 20 mol%, more preferably 10 mol%, even more preferably 8 mol%, and particularly preferably 5 mol%.

[0044] In the present invention, R in formula (I) 1 may be a methylmethyleneoxy group, and X may be a hydrogen atom. By using biomass-derived EVOH having this structural unit (modifying group), secondary processability such as stretchability and thermoformability tends to be improved without significantly deteriorating gas barrier properties. In addition, the methylmethyleneoxy group has an oxygen atom bonded to a carbon atom in the main chain. That is, in formula (IV), R 7 , R 8Preferably, one of these is a methyl group and the other is a hydrogen atom. When the biomass-derived EVOH contains the structural unit (modifying group), the lower limit of the content is preferably 0.1 mol%, more preferably 0.5 mol%, even more preferably 1.0 mol%, and particularly preferably 2.0 mol%. On the other hand, the upper limit of the content of the structural unit (modifying group) is preferably 20 mol%, more preferably 15 mol%, and even more preferably 10 mol%, from the viewpoint of improving gas barrier properties.

[0045] The biomass-derived EVOH may be used alone or in combination of two or more kinds.

[0046] When two or more types of biomass-derived EVOH are used in combination, it is preferable to use two or more types of biomass-derived EVOH with different melting points. Using two or more types of biomass-derived EVOH with different melting points tends to exhibit excellent molding processability. The gas barrier resin composition of the present invention preferably contains, as the biomass-derived EVOH, EVOH (X) and EVOH (Y) having a melting point lower than that of EVOH (X), and the mass ratio (X / Y) of EVOH (X) to EVOH (Y) is preferably 60 / 40 or more and 95 / 5 or less from the viewpoint of improving molding processability.

[0047] (EVOH(X)) EVOH (X) is an EVOH having a higher melting point than EVOH (Y), and is usually the EVOH having the highest melting point among the biomass-derived EVOHs contained in the gas barrier resin composition of the present invention. When the gas barrier resin composition of the present invention contains EVOH (X), it tends to have excellent gas barrier properties. The lower limit of the melting point of EVOH (X) is preferably 150°C, more preferably 155°C, and even more preferably 160°C. The upper limit of the melting point of EVOH (X) is preferably 200°C. When the melting point of EVOH (X) is within the above range, the gas barrier resin composition of the present invention tends to have good gas barrier properties.

[0048] The lower limit of the ethylene unit content of EVOH (X) is preferably 20 mol%, more preferably 22 mol%, and even more preferably 24 mol%, from the viewpoints of improving moldability and long-run properties. The upper limit of the ethylene unit content of EVOH (X) is preferably 50 mol%, more preferably 48 mol%, and even more preferably 46 mol%, from the viewpoints of increasing the melting point and improving gas barrier properties.

[0049] The lower limit of the saponification degree of EVOH (X) is preferably 90 mol%, more preferably 95 mol%, and even more preferably 99 mol%. When the saponification degree of EVOH (X) is 90 mol% or more, the gas barrier properties, molding processability, and long-run properties of the gas barrier resin composition of the present invention tend to be better. Furthermore, the upper limit of the saponification degree of EVOH (X) may be 100 mol%, 99.97 mol%, or 99.94 mol%.

[0050] EVOH (X) may contain monomer units other than ethylene, vinyl ester, and saponified products thereof described in the above biomass-derived EVOH, provided that the object of the present invention is not impaired. However, from the viewpoint of maintaining high gas barrier properties of the gas barrier resin composition of the present invention, it is preferable that EVOH (X) does not contain any other monomer units. When EVOH (X) contains the above other monomer units, the content of these other monomer units relative to the total structural units of EVOH (X) is preferably 5 mol % or less, more preferably 3 mol % or less, and even more preferably 1 mol % or less.

[0051] (EVOH(Y)) EVOH (Y) is a biomass-derived EVOH having a lower melting point than EVOH (X). When the gas barrier resin composition of the present invention contains EVOH (Y), it tends to exhibit excellent molding processability. The lower limit of the melting point of EVOH (Y) is preferably 100°C, more preferably 105°C, and even more preferably 110°C. The upper limit of the melting point of EVOH (Y) is preferably 180°C. When the melting point of EVOH (Y) is within the above range, the gas barrier resin composition of the present invention tends to have good gas barrier properties.

[0052] The lower limit of the ethylene unit content of EVOH (Y) is preferably 30 mol%, more preferably 32 mol%, and even more preferably 34 mol%, from the viewpoint of lowering the melting point and improving moldability and long-run properties. The upper limit of the ethylene unit content of EVOH (Y) is preferably 60 mol%, more preferably 58 mol%, and even more preferably 56 mol%, from the viewpoint of improving gas barrier properties.

[0053] The lower limit of the saponification degree of EVOH (Y) is preferably 90 mol%, more preferably 95 mol%, and even more preferably 99 mol%. When the saponification degree of EVOH (Y) is 90 mol% or higher, the gas barrier resin composition of the present invention tends to have better gas barrier properties, molding processability, and long-run properties. The upper limit of the saponification degree of EVOH (Y) may be 100 mol%, 99.97 mol%, or 99.94 mol%. The lower limit of the saponification degree of EVOH (Y) may be 70 mol% or 80 mol%, from the viewpoint of improving molding processability, and the upper limit of the saponification degree of EVOH (Y) may be 98 mol%, from the viewpoint of improving molding processability.

[0054] EVOH (Y) may contain monomer units (structural units) other than ethylene, vinyl ester, and saponified products thereof described in the biomass-derived EVOH above, as long as the objectives of the present invention are not impaired. From the viewpoint of lowering the melting point of EVOH (Y) and improving the moldability of the gas barrier resin composition of the present invention, it may be preferable for EVOH (Y) to contain other monomer units (structural units). When EVOH (Y) contains other monomer units, the lower limit of the content relative to the total structural units of EVOH (Y) is preferably 0.1 mol%, more preferably 0.3 mol%. Furthermore, the upper limit of the content is preferably 15 mol%, more preferably 10 mol%. The other monomer units (structural units) are not particularly limited, but are preferably the structural units represented by formula (I) above, more preferably the structural units represented by formula (II), formula (III), or formula (IV) above, and even more preferably formula (IV). When EVOH (Y) contains the other monomer units (structural units), moldability tends to be excellent.

[0055] The difference in ethylene unit content (YX) between EVOH (Y) and EVOH (X) is preferably 5 mol% or more, more preferably 7 mol% or more, and even more preferably 10 mol% or more. The difference in ethylene unit content (YX) may be 25 mol% or less. When the difference in ethylene unit content (YX) is within the above range, the resulting product tends to exhibit good gas barrier properties and good moldability.

[0056] The melting point difference (XY) between EVOH (X) and EVOH (Y) is preferably 15° C. or more, more preferably 18° C. or more. The melting point difference (XY) may be 100° C. or less, or may be 50° C. or less. When the melting point difference (XY) is within the above range, the resulting composition tends to exhibit good gas barrier properties and good moldability.

[0057] The mass ratio (X / Y) of EVOH (X) to EVOH (Y) is preferably 60 / 40 or more, more preferably 65 / 35 or more. The mass ratio (X / Y) is preferably 95 / 5 or less, more preferably 90 / 10 or less. When the mass ratio (X / Y) is within the above range, the resulting composition tends to exhibit good gas barrier properties while also exhibiting good molding processability.

[0058] (EVOH(Z)) The gas barrier resin composition of the present invention may contain EVOH (Z) having a lower melting point than EVOH (Y). When the gas barrier resin composition contains EVOH (Z), it tends to exhibit excellent molding processability. Suitable embodiments of EVOH (Z) are the same as those of EVOH (Y), except that EVOH (Z) has a lower melting point than EVOH (Y).

[0059] The lower limit of the melt flow rate (MFR) of the biomass-derived EVOH measured in accordance with JIS K7210:1999 at 190°C under a load of 2160 g is preferably 0.1 g / 10 min, more preferably 0.5 g / 10 min, and even more preferably 1.0 g / 10 min. Meanwhile, the upper limit of the MFR of the biomass-derived EVOH is preferably 30 g / 10 min, more preferably 20 g / 10 min, and even more preferably 15 g / 10 min. When the MFR of the biomass-derived EVOH at 190°C under a load of 2160 g is within the above range, molding processability tends to be improved.

[0060] The lower limit of the melting point of the biomass-derived EVOH is preferably 135°C, more preferably 150°C, and even more preferably 155°C. When the melting point of the biomass-derived EVOH is 135°C or higher, the gas barrier properties tend to be excellent. Furthermore, the upper limit of the melting point of the biomass-derived EVOH is preferably 200°C, more preferably 190°C, and even more preferably 185°C. When the melting point of the biomass-derived EVOH is 200°C or lower, the molding processability tends to be improved.

[0061] The lower limit of the proportion of biomass-derived EVOH in all resins constituting the gas barrier resin composition of the present invention is preferably 80% by mass, more preferably 90% by mass, even more preferably 95% by mass, particularly preferably 98% by mass, or even 99% by mass, and the resins constituting the gas barrier resin composition of the present invention may consist essentially of biomass-derived EVOH alone, or may consist solely of biomass-derived EVOH. Furthermore, the lower limit of the proportion of biomass-derived EVOH in the gas barrier resin composition of the present invention is preferably 80% by mass, more preferably 90% by mass, even more preferably 95% by mass, particularly preferably 98% by mass, or may even be 99% by mass, and the gas barrier resin composition of the present invention may consist essentially of biomass-derived EVOH alone.

[0062] From the perspective of tracking one's own products, it is preferable for the gas barrier resin composition of the present invention to contain sulfur compounds in an amount greater than 0 ppm and less than 100 ppm, calculated as sulfur atoms. Furthermore, the inventors have found that sulfur compounds at 100 ppm or less, calculated as sulfur atoms, do not substantially affect the performance of the gas barrier resin composition, making these sulfur compounds suitable as tracer substances. The upper limit of the sulfur compound content is more preferably 50 ppm, even more preferably 5 ppm, even more preferably 3 ppm, and particularly preferably 1.5 ppm. The lower limit of the sulfur compound content may be 0.0001 ppm, 0.001 ppm, 0.01 ppm, 0.05 ppm, or 0.1 ppm. When biomass-derived raw materials are used, EVOH containing organic sulfur compounds contained in the biomass raw materials may be obtained. On the other hand, fossil fuel-derived EVOH contains fewer sulfur compounds than biomass-derived EVOH because it is desulfurized during naphtha cracking. Therefore, when using such biomass-derived EVOH, comparing the sulfur compound content makes it easier to track the biomass-derived EVOH. In particular, when the gas barrier resin composition of the present invention contains an organic sulfur compound, particularly dimethyl sulfide or dimethyl sulfoxide, as the sulfur compound, tracking becomes even easier. Furthermore, from the viewpoint of tracking one's own products, it may be preferable not to perform excessive purification of the raw materials, biomass-derived ethylene and biomass-derived vinyl ester, and the resulting EVOH during the production of EVOH, so as to reduce the content of sulfur compounds to below the detection limit.

[0063] (Other ingredients) The gas barrier resin composition of the present invention preferably further contains a carboxylic acid. When the gas barrier resin composition of the present invention contains a carboxylic acid, melt moldability and coloration resistance at high temperatures can be improved. In particular, the pKa of the carboxylic acid is more preferably in the range of 3.5 to 5.5, as this may increase the pH buffering ability of the gas barrier resin composition and improve coloration resistance to acidic and basic substances.

[0064] When the gas barrier resin composition of the present invention contains a carboxylic acid, the lower limit of the content is preferably 30 ppm, more preferably 100 ppm, calculated as a carboxylic acid radical. Meanwhile, the upper limit of the carboxylic acid content is preferably 1000 ppm, more preferably 600 ppm. A carboxylic acid content of 30 ppm or more tends to improve resistance to discoloration at high temperatures. Meanwhile, a carboxylic acid content of 1000 ppm or less tends to improve melt moldability. The carboxylic acid content is calculated by titrating the extract obtained by extracting 10 g of the resin composition with 50 ml of pure water at 95°C for 8 hours. Here, the content of carboxylic acid salts present in the extract is not taken into consideration when determining the carboxylic acid content in the resin composition. Furthermore, the carboxylic acid may exist as a carboxylate ion.

[0065] Examples of carboxylic acids include monocarboxylic acids and polycarboxylic acids, and these may be used alone or in combination. When the carboxylic acid contains both a monocarboxylic acid and a polycarboxylic acid, the melt moldability and coloration resistance at high temperatures of the gas barrier resin composition may be further improved. Furthermore, the polycarboxylic acid may have three or more carboxy groups. In this case, the coloration resistance of the gas barrier resin composition of the present invention may be further improved.

[0066] A monocarboxylic acid is a compound having one carboxy group in the molecule. The pKa of the monocarboxylic acid is preferably in the range of 3.5 to 5.5. Examples of such monocarboxylic acids include formic acid (pKa = 3.77), acetic acid (pKa = 4.76), propionic acid (pKa = 4.85), butyric acid (pKa = 4.82), caproic acid (pKa = 4.88), capric acid (pKa = 4.90), lactic acid (pKa = 3.86), acrylic acid (pKa = 4.25), methacrylic acid (pKa = 4.65), benzoic acid (pKa = 4.20), and 2-naphthoic acid (pKa = 4.17). These carboxylic acids may have a substituent such as a hydroxyl group, an amino group, or a halogen atom, as long as their pKa is in the range of 3.5 to 5.5. Among these, acetic acid is preferred due to its high safety and ease of handling.

[0067] A polycarboxylic acid is a compound having two or more carboxy groups in the molecule, and in this case, it is preferable that the pKa of at least one of the carboxy groups is in the range of 3.5 to 5.5. Examples of such polycarboxylic acids include oxalic acid (pKa2 = 4.27), succinic acid (pKa1 = 4.20), fumaric acid (pKa2 = 4.44), malic acid (pKa2 = 5.13), glutaric acid (pKa1 = 4.30, pKa2 = 5.40), adipic acid (pKa1 = 4.43, pKa2 = 5.41), pimelic acid (pKa1 = 4.71), phthalic acid (pKa2 = 5.41), isophthalic acid (pKa2 = 4.46), terephthalic acid (pKa1 = 3.51, pKa2 = 4.82), citric acid (pKa2 = 4.75), tartaric acid (pKa2 = 4.40), glutamic acid (pKa2 = 4.07), and aspartic acid (pKa = 3.90).

[0068] The gas barrier resin composition of the present invention preferably further contains a phosphate compound. When the gas barrier resin composition of the present invention contains a phosphate compound, the lower limit of the content is preferably 1 ppm, more preferably 3 ppm, calculated as phosphate radicals. On the other hand, the upper limit of the content is preferably 200 ppm, more preferably 100 ppm, calculated as phosphate radicals. When the phosphate compound is contained within this range, the thermal stability of the gas barrier resin composition of the present invention may be improved. In particular, the generation of gel-like particles and coloration during long-term melt molding may be suppressed. As the phosphate compound, for example, various acids such as phosphoric acid and phosphorous acid, and salts thereof, can be used. The phosphate may be in the form of a primary phosphate, a secondary phosphate, or a tertiary phosphate. Examples of cationic species of the phosphate include alkali metals and alkaline earth metals. Specific examples of the phosphate compound include sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, and dipotassium hydrogen phosphate.

[0069] The gas barrier resin composition of the present invention preferably further contains a boron compound. When the gas barrier resin composition of the present invention contains a boron compound, the lower limit of the content is preferably 5 ppm, more preferably 100 ppm, calculated as boron atoms. On the other hand, the upper limit of the content is preferably 5,000 ppm, more preferably 1,000 ppm, calculated as boron atoms. When the boron compound is contained within this range, the thermal stability of the gas barrier resin composition of the present invention during melt molding can be improved, and the occurrence of gel-like particles can be suppressed. Furthermore, the mechanical properties of the resulting molded article can be improved. These effects are presumably due to the chelating interaction between the EVOH and the boron compound. Examples of boron compounds include boric acid, borate esters, borates, and boron hydrides. Specifically, examples of boric acids include orthoboric acid (H3BO3), metaboric acid, and tetraboric acid; examples of boric acid esters include trimethyl borate and triethyl borate; and examples of boric acid salts include alkali metal salts, alkaline earth metal salts, and borax of the above-mentioned boric acids.

[0070] The gas barrier resin composition of the present invention preferably further contains metal ions. When the gas barrier resin composition of the present invention contains metal ions, the interlayer adhesion is excellent when the composition is formed into a multilayer molded article, i.e., a multilayer structure. The reason for the improved interlayer adhesion is unclear, but it is thought that when a layer adjacent to a layer made of the gas barrier resin composition contains a molecule having a functional group capable of reacting with a hydroxy group of EVOH, the metal ions accelerate the bond formation reaction between the two. Furthermore, controlling the content ratio of the metal ions to the above-mentioned carboxylic acid can also improve the melt moldability and coloration resistance of the gas barrier resin composition of the present invention.

[0071] When the gas barrier resin composition of the present invention contains metal ions, the lower limit of the metal ion content is preferably 1 ppm, more preferably 100 ppm, and even more preferably 150 ppm. On the other hand, the upper limit of the metal ion content is preferably 1000 ppm, more preferably 400 ppm, and even more preferably 350 ppm. When the metal ion content is 1 ppm or more, the interlayer adhesion of the resulting multilayer structure tends to be good. On the other hand, when the metal ion content is 1000 ppm or less, the discoloration resistance tends to be good.

[0072] Examples of metal ions include monovalent metal ions, divalent metal ions, and other transition metal ions, and these may be used alone or in combination of two or more. Of these, monovalent metal ions and divalent metal ions are preferred.

[0073] The monovalent metal ion is preferably an alkali metal ion, such as lithium, sodium, potassium, rubidium, or cesium ions, with sodium or potassium ions being preferred from the viewpoint of industrial availability. Examples of alkali metal salts that provide alkali metal ions include aliphatic carboxylates, aromatic carboxylates, carbonates, hydrochlorides, nitrates, sulfates, phosphates, and metal complexes. Among these, aliphatic carboxylates and phosphates are preferred from the viewpoint of availability, and specifically, sodium acetate, potassium acetate, sodium phosphate, and potassium phosphate are preferred.

[0074] It may be preferable to include a divalent metal ion as the metal ion. When the metal ion includes a divalent metal ion, for example, thermal degradation of EVOH when trim is recovered and reused may be suppressed, and the occurrence of gels and lumps in the resulting molded article may be suppressed. Examples of divalent metal ions include beryllium, magnesium, calcium, strontium, barium, and zinc ions, with magnesium, calcium, or zinc ions being preferred from the viewpoint of industrial ease of availability. Furthermore, examples of divalent metal salts that provide divalent metal ions include carboxylates, carbonates, hydrochlorides, nitrates, sulfates, phosphates, and metal complexes, with carboxylates being preferred. The carboxylic acid constituting the carboxylate is preferably a carboxylic acid having 1 to 30 carbon atoms, specifically, acetic acid, stearic acid, lauric acid, montanic acid, behenic acid, octylic acid, sebacic acid, ricinoleic acid, myristic acid, palmitic acid, etc., with acetic acid and stearic acid being particularly preferred.

[0075]

[0043] The gas barrier resin composition of the present invention may contain other components, such as antiblocking agents, processing aids, resins other than EVOH, stabilizers, antioxidants, UV absorbers, plasticizers, antistatic agents, lubricants, colorants, fillers, surfactants, desiccants, oxygen absorbers, crosslinking agents, and reinforcing agents such as various fibers, as long as the effects of the present invention are not impaired.

[0076]

[0033] Examples of the anti-blocking agent include oxides, nitrides, and oxynitrides of elements selected from silicon, aluminum, magnesium, zirconium, cerium, tungsten, molybdenum, etc., and among these, silicon oxide is preferred because of its easy availability. By including an anti-blocking agent in the gas barrier resin composition of the present invention, blocking resistance can be improved.

[0077] Examples of the processing aid include fluorine-based processing aids such as Kynar (trademark) manufactured by Arkema and Dynamer (trademark) manufactured by 3M. When the gas barrier resin composition of the present invention contains a processing aid, it tends to be possible to prevent eye discharge from adhering to the die lip.

[0078] Examples of resins other than EVOH include various polyolefins (polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymers, copolymers of ethylene and an α-olefin having 4 or more carbon atoms, copolymers of polyolefins and maleic anhydride, ethylene-vinyl ester copolymers, ethylene-acrylic acid ester copolymers, and modified polyolefins obtained by graft-modifying any of these with an unsaturated carboxylic acid or a derivative thereof), various polyamides (nylon 6, nylon 6·6, nylon 6 / 66 copolymer, nylon 11, nylon 12, polymetaxylylene adipamide, etc.), various polyesters (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylonitrile, polyurethane, polycarbonate, polyacetal, polyacrylate, and modified polyvinyl alcohol resins.

[0079] Examples of stabilizers for improving melt stability include hydrotalcite compounds, hindered phenol and hindered amine heat stabilizers, metal salts of higher aliphatic carboxylic acids (e.g., calcium stearate, magnesium stearate, etc.), etc. When the gas barrier resin composition of the present invention contains a stabilizer, the content thereof is preferably 0.001 to 1% by mass.

[0080] Examples of antioxidants include 2,5-di-t-butyl-hydroquinone, 2,6-di-t-butyl-p-cresol, 4,4'-thiobis-(6-t-butylphenol), 2,2'-methylene-bis-(4-methyl-6-t-butylphenol), octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, and 4,4'-thiobis-(6-t-butylphenol).

[0081] Examples of ultraviolet absorbers include ethylene-2-cyano-3',3'-diphenylacrylate, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, and 2,2'-dihydroxy-4-methoxybenzophenone.

[0082] Examples of the plasticizer include dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, and phosphate esters.

[0083] Examples of antistatic agents include pentaerythritol monostearate, sorbitan monopalmitate, sulfated polyolefins, polyethylene oxide, and carbowax.

[0084] Examples of the lubricant include ethylene bisstearamide and butyl stearate.

[0085] Examples of colorants include carbon black, phthalocyanine, quinacridone, indoline, azo pigments, and red iron oxide.

[0086] Examples of fillers include glass fiber, asbestos, ballastonite, calcium silicate, and the like.

[0087] Examples of desiccants include phosphates (excluding the above-mentioned phosphates), sodium borate, sodium sulfate, sodium chloride, sodium nitrate, sugar, silica gel, bentonite, molecular sieves, and superabsorbent resins.

[0088] From the viewpoint of preventing the occurrence of voids during molding, the water content of the gas barrier resin composition of the present invention is preferably 3.0 parts by mass or less, more preferably 1.0 part by mass or less, even more preferably 0.5 part by mass or less, and particularly preferably 0.3 part by mass or less, per 100 parts by mass of the total biomass-derived EVOH.

[0089] The gas barrier resin composition of the present invention may contain biomass-derived impurities resulting from the biomass-derived EVOH. Although it may contain various impurities, it tends to contain large amounts of metals such as iron and nickel.

[0090] (Bio-based content of gas barrier resin composition) The biobased content of the gas barrier resin composition of the present invention is preferably greater than 99%, more preferably greater than 99.5%, and may be 100%. The biobased content of the gas barrier resin composition is a value measured taking into consideration other resins contained in optional components other than EVOH. It is preferable that the biobased content of the gas barrier resin composition of the present invention is within the above range, as this has an extremely low environmental impact.

[0091] The method for incorporating the other components into the gas barrier resin composition of the present invention is not particularly limited. The composition can be produced by melt-kneading the other components and additives with biomass-derived EVOH. Each component may be blended in a solid state, such as a powder, or as a melt. Alternatively, the components may be blended as a solute in a solution or a dispersoid in a dispersion. An aqueous solution and an aqueous dispersion are preferred as the solution and dispersion, respectively. For melt-kneading, known mixing or kneading devices, such as a kneader-ruder, extruder, mixing roll, or Banbury mixer, can be used. The temperature range during melt-kneading can be adjusted appropriately depending on the biomass-derived EVOH used and the melting point of each component, and is typically 150 to 250°C. Alternatively, the composition can be produced by pre-adding some components to biomass-derived EVOH and then melt-kneading additional components as described above. An example of a method for pre-adding some components to biomass-derived EVOH is immersing biomass-derived EVOH in the form of pellets or powder in a solution containing the additional components. An aqueous solution is preferred as the solution.

[0092] <Molded body> A molded article comprising a layer formed from the gas barrier resin composition of the present invention (hereinafter also referred to as a "gas barrier resin composition layer") is a suitable embodiment of the present invention. The gas barrier resin composition of the present invention can be formed into a molded article of a single layer structure, or a molded article (laminate) further comprising a thermoplastic resin layer. The thermoplastic resin layer refers to a layer containing a thermoplastic resin as the main component. The molded article of the present invention may further comprise an adhesive resin layer (adhesive layer). The adhesive resin layer refers to a layer containing an adhesive resin, an anchor coating agent, or an adhesive as the main component. Here, "main component" means that the proportion of that component exceeds 50% by mass, and preferably is 90% by mass or more. The molded article of the present invention may further comprise other layers.

[0093] In this way, the molded article of the present invention can also be made into a multilayer structure (laminate). The lower limit of the number of layers of the molded article of the present invention may be 1, but is preferably 2, and more preferably 3. The upper limit of the number of layers of the molded article may be, for example, 1000, 100, 20, or 10. The molded article has a low environmental impact and exhibits good gas barrier properties, appearance, moldability, etc. The uses of molded articles using the gas barrier resin composition of the present invention are diverse, and include, for example, films, sheets, containers, bottles, tanks, pipes, hoses, etc.

[0094] Specific molding methods include extrusion molding for films, sheets, pipes, and hoses, injection molding for container shapes, and blow molding or rotational molding for hollow containers such as bottles and tanks. Examples of blow molding include extrusion blow molding, in which a parison is formed by extrusion molding and then blown to form a hollow container, and injection blow molding, in which a preform is formed by injection molding and then blown to form a hollow container. For the production of flexible packaging materials and containers, a method of forming a packaging material such as a multilayer film by extrusion molding, and a method of thermoforming a multilayer sheet formed by extrusion molding into a container-shaped packaging material are preferably used.

[0095] The multilayer structure includes at least one gas barrier resin composition layer and a thermoplastic resin layer. The multilayer structure is typically obtained by laminating a gas barrier resin composition layer with another layer (thermoplastic resin layer). The layer structure may have a layer structure such as x / y, x / y / x, x / z / y, x / z / y / z / x, x / y / x / y / x / y / x, or x / z / y / z / x / z / y / z / x / z / x. When multiple x, y, and z layers are provided, the layers may be the same or different. A separate layer may be provided using recycled resin made from scraps such as trim generated during molding, or the recycled resin may be mixed with a layer made from another resin. From the standpoints of moldability and cost, the thickness of each layer in the multilayer structure is typically 2 to 20% of the total thickness of the y layer.

[0096] The resin used for the x layer is preferably a thermoplastic resin from the viewpoint of processability, etc. Examples of thermoplastic resins include various polyolefins (polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, copolymers of ethylene and an α-olefin having 4 or more carbon atoms, copolymers of polyolefin and maleic anhydride, ethylene-vinyl ester copolymers, ethylene-acrylic acid ester copolymers, and modified polyolefins obtained by graft-modifying these with unsaturated carboxylic acids or their derivatives), various polyamides (nylon 6, nylon 6·6, nylon 6 / 66 copolymer, nylon 11, nylon 12, polymetaxylylene adipamide, etc.), various polyesters (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylonitrile, polyurethane, polycarbonate, polyacetal, polyacrylate, and modified polyvinyl alcohol resins. Such thermoplastic resin layers may be unstretched, uniaxially or biaxially stretched, or rolled. Among these, polyolefins are preferred in terms of moisture resistance, mechanical properties, cost efficiency, and heat sealability, while polyamides and polyesters are preferred in terms of mechanical properties and heat resistance.

[0097] The adhesive resin used in the z layer is a resin having adhesive properties, and is preferably a thermoplastic resin having adhesive properties. A suitable adhesive resin is, for example, a carboxylic acid-modified polyolefin. Here, the carboxylic acid-modified polyolefin refers to a polyolefin copolymer containing an unsaturated carboxylic acid or its anhydride (such as maleic anhydride) as a copolymerization component; or a graft copolymer obtained by grafting an unsaturated carboxylic acid or its anhydride onto a polyolefin.

[0098] The z-layer can also be made of an adhesive, an anchor coating agent, or the like. The anchor coating agent and adhesive may be a resin, or may be a non-resin material such as a low-molecular-weight compound, or may be composed of multiple components. The z-layer can be formed by applying these and drying them as needed. Adhesion may be enhanced by performing a surface treatment, such as corona discharge treatment, on the coating surface before application. The adhesive is not particularly limited, and it is preferable to use, for example, a two-component reactive polyurethane adhesive in which a polyisocyanate component and a polyol component are mixed and reacted. Furthermore, adhesion may be further enhanced by adding a small amount of a known silane coupling agent. Suitable examples of silane coupling agents include silane coupling agents having reactive groups such as an isocyanate group, an epoxy group, an amino group, a ureido group, or a mercapto group.

[0099] The multilayer structure may further have a paper substrate layer. As the paper substrate used for the paper substrate layer, any paper having various shapeability, flex resistance, rigidity, stiffness, strength, etc. can be used depending on the application of the paper container. For example, various types of paper can be used, such as bleached or unbleached paper that is the main strength material and has strong sizing properties, or pure white roll paper, kraft paper, paperboard, processed paper, or milk base paper. The paper substrate layer may be a laminate of multiple layers of these papers. The paper substrate layer has a basis weight of 80 to 600 g / m. 2 , preferably 100 to 450 g / m 2 The thickness is in the range of 110 to 860 μm, preferably 140 to 640 μm. If the thickness of the paper base layer is thinner than this range, the strength as a container will be insufficient, and if the thickness of the paper base layer is thicker than this range, the rigidity will be too high, which may make processing difficult. Note that, for example, letters, figures, symbols, and other desired patterns can be formed on the paper base layer using a normal printing method.

[0100] Methods for obtaining a multilayer structure include, for example, coextrusion molding, coextrusion blow molding, coinjection molding, extrusion lamination, coextrusion lamination, dry lamination, solution coating, etc. The multilayer structure obtained by such a method may be further reheated and then subjected to secondary processing molding using methods such as vacuum-pressure deep drawing, blow molding, and press molding to obtain the desired molded structure. The multilayer structure may also be reheated at or below the melting point of EVOH and then uniaxially or biaxially stretched using methods such as roll stretching, pantograph stretching, and inflation stretching to obtain a stretched multilayer structure. Methods for producing films or sheets, packaging materials, industrial films or sheets, thermoformed containers, cup-shaped containers, tray-shaped containers, blow-molded containers, fuel containers, bottle containers, tubes, multilayer pipes, and paper containers, which will be described later, are also included in the methods for producing molded articles of the present invention.

[0101] Examples of single-layer or multi-layer molded articles using the gas barrier resin composition of the present invention include containers (bags, cups, tubes, trays, bottles, etc.), fuel containers, pipes, fibers, food and beverage packaging, container packing materials, medical infusion bag materials, tire tube materials, shoe cushioning materials, bag-in-box inner bag materials, organic liquid storage tank materials, organic liquid transport pipe materials, heating hot water pipe materials (hot water pipe materials for floor heating, etc.), cosmetic packaging materials, dental care packaging materials, pharmaceutical packaging materials, packaging subparts (caps, bag-in-box cock parts, etc.), pesticide bottles, agricultural films (greenhouse films, soil fumigation films), grain storage bags, geomembranes, vacuum insulation outer bags, wallpaper or decorative panels, gas tanks for hydrogen, oxygen, etc. Some examples are specifically described below.

[0102] <Film or sheet> The film or sheet of the present invention comprises the molded article of the present invention. The term "film" refers to a "soft, film-like material having an average thickness of less than 250 μm," and the term "sheet" refers to a "soft, thin, plate-like material having an average thickness of 250 μm or more." The same applies to the distinction between film and sheet in industrial "film or sheet." Hereinafter, "film or sheet" will also be referred to as "film, etc." The film, etc. of the present invention may be a film, etc., made from the molded article of the present invention. That is, one embodiment of the molded article of the present invention may be a film, etc. The film, etc. of the present invention has a low environmental impact and is excellent in gas barrier properties, appearance, and moldability. The film, etc. of the present invention may be a single-layer film made only of a gas barrier resin composition layer, or may be a multilayer film. The average thickness of the film, etc. of the present invention is preferably 1 μm or more but less than 300 μm, and more preferably 5 μm or more but less than 100 μm. The film, etc. of the present invention can be suitably used as various packaging materials, etc.

[0103] The arithmetic mean roughness (Ra) of at least one surface of the film of the present invention, measured in accordance with JIS B0601, is preferably 1.0 μm or less, more preferably 0.8 μm or less, even more preferably 0.6 μm or less, and particularly preferably 0.4 μm or less. The arithmetic mean roughness (Ra) of at least one surface of the film of the present invention is preferably 0.05 μm or more, more preferably 0.10 μm or more, even more preferably 0.15 μm or more, and particularly preferably 0.20 μm or more. When the arithmetic mean roughness (Ra) of at least one surface of the film of the present invention is within the above range, excellent break resistance is achieved.

[0104] The average length (RSm) of the profile elements on at least one surface of the film of the present invention, measured in accordance with JIS B0601, is preferably 1000 μm or less, more preferably 800 μm or less, even more preferably 600 μm or less, and particularly preferably 400 μm or less. The average length (RSm) of the profile elements on at least one surface of the film of the present invention is preferably 50 μm or more, more preferably 100 μm or more, even more preferably 150 μm or more, and particularly preferably 200 μm or more. When the average length (RSm) of the profile elements on at least one surface of the film of the present invention is within the above range, excellent break resistance is achieved. Note that JIS B0601 refers to JIS B0601:2001.

[0105] The film of the present invention may be an unstretched film, but is preferably stretched. Stretching improves strength and other properties. Furthermore, when the film of the present invention is a stretched film, the film is less prone to streaky irregularities that can occur during stretching, resulting in good appearance and gas barrier properties. The film of the present invention may also be a heat-shrinkable film.

[0106] (Manufacturing method of film, etc.) The film of the present invention can be produced by a known method. The method for forming the film is not particularly limited and includes, for example, a melting method, a solution method, and a calendaring method, with the melting method being preferred. Melting methods include a T-die method (casting method) and an inflation method, with the casting method being preferred. In particular, the film of the present invention is preferably produced by a method comprising a cast molding step of melt-extruding the resin composition constituting the film onto a casting roll, and a step of stretching an unstretched film obtained from the resin composition. The melting temperature in the melting method varies depending on the melting point of the gas barrier resin composition of the present invention, but is preferably about 150 to 300°C.

[0107] The stretching may be uniaxial or biaxial, with biaxial stretching being preferred. Biaxial stretching may be either sequential biaxial stretching or simultaneous biaxial stretching. The lower limit of the area-equivalent stretching ratio is preferably 6 times, more preferably 8 times. The upper limit of the stretching ratio is preferably 15 times, more preferably 12 times. When the stretching ratio is within the above range, the thickness uniformity of the film, etc., the gas barrier properties, and the mechanical strength can be improved. The stretching temperature can be, for example, from 60°C to 120°C.

[0108] The method for producing a film or the like of the present invention may include, after the stretching step, a step of heat-treating the stretched film or the like. The heat-treatment temperature is usually set to a temperature higher than the stretching temperature, and can be, for example, higher than 120°C and 200°C or lower.

[0109] The film etc. of the present invention is suitably used as a material for various packaging containers such as food packaging containers, pharmaceutical packaging containers, industrial chemical packaging containers, agricultural chemical packaging containers, etc. In addition, heat-shrinkable films etc. and industrial films etc., which will be described later, are also included in one embodiment of the film etc. of the present invention.

[0110] <Packaging material> The packaging material of the present invention includes the film or sheet of the present invention. The packaging material of the present invention may be a packaging material made of the film or sheet of the present invention. That is, one embodiment of the molded article of the present invention may be a packaging material. The packaging material of the present invention has a low environmental impact and is also good in gas barrier properties, appearance, and moldability.

[0111] The packaging material of the present invention may be a single-layer film or a multilayer film. Furthermore, the multilayer film may further include a layer formed from a material other than resin, such as a paper layer or a metal layer. The packaging material of the present invention may be in the form of a film or sheet, or may be a film or sheet that has been subjected to secondary processing. Examples of packaging materials obtained by secondary processing include (1) tray-cup-shaped containers obtained by thermoforming a film or sheet using methods such as vacuum forming, pressure forming, and vacuum-pressure forming; (2) bottles and cup-shaped containers obtained by stretch-blow molding a film or sheet; and (3) bag-shaped containers obtained by heat-sealing a film or sheet. The secondary processing method is not limited to the methods exemplified above, and other known secondary processing methods, such as blow molding, can also be used as appropriate.

[0112] The packaging material of the present invention is used for packaging, for example, foods, beverages, chemicals such as pesticides and medicines, medical equipment, machine parts, industrial materials such as precision materials, clothing, etc. In particular, the packaging material of the present invention is preferably used for applications requiring barrier properties against oxygen and applications in which the interior of the packaging material is replaced with various functional gases. The packaging material of the present invention is formed into various forms depending on the application, such as vertical form-fill-seal bags, vacuum packaging bags, pouches with spouts, laminated tube containers, container lids, etc.

[0113] <Vacuum packaging bag> The packaging material of the present invention may be a vacuum packaging bag. One example of a vacuum packaging bag is a bag-shaped container that includes the film of the present invention as a partition that separates the interior where the contents are packaged from the exterior, and the interior is in a reduced pressure state. In a vacuum packaging bag, for example, two films of the present invention are overlapped, and the peripheral edges of these two films are sealed to each other. In a vacuum packaging bag, a multilayer film or the like is preferably used as the partition. Vacuum packaging bags can be produced using a nozzle-type or chamber-type vacuum packaging machine.

[0114] The vacuum packaging bag is used for applications where packaging in a vacuum state is desired, such as preserving food, beverages, etc. The vacuum packaging bag can also be used as an outer packaging material for vacuum insulators.

[0115] <Industrial film or sheet> The industrial film or sheet (industrial film or industrial sheet) of the present invention comprises a molded article such as a single-layer or multilayer film of the present invention. The industrial film of the present invention may be an industrial film made of the molded article of the present invention. That is, one embodiment of the molded article of the present invention may be an industrial film. The industrial film of the present invention has a low environmental impact and is also excellent in gas barrier properties, appearance, and moldability. Specific examples of industrial films include agricultural films, landfill films, and construction films.

[0116] The industrial film etc. of the present invention is preferably a multilayer film etc., and a hydrophobic thermoplastic resin is preferably used as the thermoplastic resin layer for the purpose of preventing deterioration of the gas barrier performance of the gas barrier resin composition layer due to moisture. Specific examples of the polyolefin resin include polyethylenes such as linear low-density polyethylene, low-density polyethylene, very low-density polyethylene, very low-density linear polyethylene, medium-density polyethylene, and high-density polyethylene, polyethylene resins such as ethylene-α-olefin copolymers, polypropylene resins such as polypropylene, ethylene-propylene (block and random) copolymers, and propylene-α-olefin (α-olefin copolymers having 4 to 20 carbon atoms), polybutene, and polypentene; grafted polyolefins obtained by graft-modifying these polyolefins with unsaturated carboxylic acids or their esters, and cyclic polyolefin resins; ionomers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymers, polyester resins, polyamide resins, polyvinyl chloride, polyvinylidene chloride, acrylic resins, polystyrene, vinyl ester resins, polyester elastomers, polyurethane elastomers, halogenated polyolefins such as chlorinated polyethylene and chlorinated polypropylene, and aromatic or aliphatic polyketones. Among these, polyolefin resins are preferred in terms of mechanical strength and moldability, and polyethylene and polypropylene are particularly preferred.

[0117] Regarding the melt viscosity of the hydrophobic thermoplastic resin, the lower limit of the MFR at 210°C under a load of 2160 g is preferably 1.0 g / 10 min, more preferably 2.0 g / 10 min, and the upper limit is preferably 100 g / 10 min, more preferably 60 g / 10 min. By using a hydrophobic thermoplastic resin composition having such a melt viscosity, a good multilayer film without layer disorder can be obtained.

[0118] The layer structure of the industrial film etc. of the present invention can be exemplified by the following layer configuration, where the layer made of a resin other than the gas barrier resin composition of the present invention is layer x, the gas barrier resin composition layer is layer y, and the adhesive resin layer is layer z. The layer configuration indicates that the layer on the left is the outer layer (the side exposed to the external environment). 5 layers y / z / x / z / y, x / z / y / z / x, x / z / y / z / y 6 layers x / z / y / z / x / x 7 layers x / z / y / z / y / z / x, x / x / z / y / z / x / x

[0119] In particular, for the purpose of preventing a decrease in oxygen barrier properties due to moisture, a configuration using a gas barrier resin composition layer as an intermediate layer and a thermoplastic resin layer as an outer layer is preferred, and a configuration such as x / z / y / z / x or x / x / z / y / z / x / x is more preferred.

[0120] The total thickness of the industrial film of the present invention is usually 5 to 5 mm, preferably 10 to 4.5 mm, more preferably 15 to 4 mm, and particularly preferably 20 to 3.5 mm. The thickness of the hydrophobic resin composition layer in the industrial film is not particularly limited, but is usually 0.5 to 2.5 mm, preferably 1 to 2 mm, and particularly preferably 1 to 1.5 mm. The thickness of the thermoplastic resin layer is not particularly limited, but is preferably in the range of 1 to 20%, preferably 2 to 18%, and more preferably 3 to 15% of the total layer thickness.

[0121] Examples of the architectural film etc. include wallpaper etc. Wallpaper as one embodiment of the industrial film etc. of the present invention has a small environmental impact and is excellent in productivity.

[0122] Examples of the landfill films include geomembranes and landfill sheets. Geomembranes are sheets used as waterproofing at waste disposal sites. Landfill sheets are sheets that prevent the diffusion of harmful substances from industrial waste, etc., and can be used to prevent the diffusion of radon gas, for example.

[0123] In the above agricultural films, etc., it is preferable that the gas barrier resin composition contains an antioxidant or an ultraviolet resistant agent (ultraviolet absorber, light stabilizer, colorant), etc., from the viewpoint of enabling long-term outdoor use. The above agricultural films, etc. are preferably multilayer films, etc., and a hydrophobic thermoplastic resin is preferably used as the thermoplastic resin layer for the purpose of preventing deterioration of the gas barrier performance of the gas barrier resin composition layer due to moisture.

[0124] The thermoplastic resin layer preferably contains an ultraviolet resistant agent or an adhesive component. Examples of the ultraviolet resistant agent include an ultraviolet absorber, a light stabilizer, and a colorant.

[0125] The amount of the UV-resistant agent added to the hydrophobic thermoplastic resin is usually 1 to 10% by mass, preferably 2 to 8% by mass, and particularly preferably 3 to 5% by mass. If the amount added is less than this range, the hydrophobic thermoplastic resin is more likely to be deteriorated by UV rays. On the other hand, if the amount added is more than this range, the mechanical strength of the hydrophobic thermoplastic resin decreases.

[0126] Examples of the adhesive component include aliphatic saturated hydrocarbon resins such as polyisobutene and alicyclic saturated hydrocarbon resins. The blending amount relative to the hydrophobic thermoplastic resin is typically 1 to 30% by mass, preferably 2 to 20% by mass, and particularly preferably 3 to 15% by mass. If the blending amount is appropriate, the films are pressed together when wrapping using the agricultural film, etc., making it easier to maintain a tight seal. If the blending amount is less than the above range, gaps will form between the films, etc., allowing air to enter the interior, resulting in poor long-term storage of the contents. Furthermore, if the blending amount is greater than the above range, blocking of the multilayer film will occur, making it impossible to unwind it from a film roll, etc.

[0127] The total thickness of the agricultural film is usually 5 to 200 μm, preferably 10 to 150 μm, more preferably 15 to 100 μm, and particularly preferably 20 to 50 μm. The thickness of the thermoplastic resin layer (hydrophobic resin composition layer, etc.) in the agricultural film is not particularly limited, but is usually 0.5 to 200 μm, preferably 1 to 100 μm, and particularly preferably 1 to 10 μm. The thickness of the gas barrier resin composition layer is not particularly limited, but is preferably 1 to 20% of the total layer thickness, preferably 2 to 18%, and more preferably 3 to 15%.

[0128] The form of the silo using the above agricultural film or the like is not particularly limited, and examples thereof include wrap silos, bunker silos, bag silos, tube silos, and stack silos, with wrap silos being particularly suitable.

[0129] When preparing a wrap silo, first, pasture is formed into the desired volume using a machine such as a roll baler. Then, the formed pasture is wrapped with the agricultural film or the like using a machine such as a bale wrapper, and sealed. Because the amount of air remaining during sealing affects the quality of the contents, it is preferable to apply tension to the agricultural film or the like while stretching it and wrapping it around the contents, so that the film or the like is tightly attached to the contents.

[0130] The above-mentioned agricultural films and the like can be used for various purposes such as greenhouse films, soil fumigation films, silage films, silo bags, grain storage bags, and the like.

[0131] <Tube> The tube of the present invention comprises the molded article of the present invention. The tube of the present invention may be a tube made of the molded article of the present invention. That is, one embodiment of the molded article of the present invention may be a tube. The tube of the present invention has a low environmental impact and is also good in gas barrier properties, appearance, and moldability.

[0132] The method for producing the tube of the present invention is not particularly limited, and examples thereof include a method in which the tube is directly formed into a tube by melt molding such as coextrusion molding, coinjection molding, or extrusion coating, a method in which the film or sheet of the present invention is heat-sealed to form a tube, and a method in which the film or sheet of the present invention is laminated with an adhesive to form a tube.

[0133] <Multi-layer pipe> The multilayer pipe of the present invention comprises the molded article of the present invention. The multilayer pipe of the present invention may be a multilayer pipe made of the molded article of the present invention. That is, one embodiment of the molded article of the present invention may be a multilayer pipe. The multilayer pipe of the present invention has a low environmental impact and is also excellent in gas barrier properties, appearance, and moldability. From the viewpoint of suppressing oxidative degradation during long-term use, the multilayer pipe of the present invention preferably contains an antioxidant in the gas barrier resin composition. The antioxidant is preferably a compound having a hindered amine group and / or a compound having a hindered phenol group, from the viewpoint of suppressing oxidative degradation during use at high temperatures.

[0134] The layer structure of the multilayer pipe can be the same as that of the molded article described above. When the multilayer pipe is used as a hot water circulation pipe, a three-layer structure of thermoplastic resin layer / gas barrier resin composition layer / thermoplastic resin layer, with the thermoplastic resin layer as the outermost layer, is generally adopted. This is because an existing production line for single-layer pipes such as crosslinked polyolefin can be easily converted into a production line for the multilayer pipe of the present invention by adding co-extrusion coating equipment for the gas barrier resin composition of the present invention and an adhesive resin, and in fact many pipe manufacturers have adopted this structure.

[0135] Providing polyolefin layers or the like on both sides of a gas barrier resin composition layer and using the gas barrier resin composition layer as an intermediate layer is effective in preventing scratches on the gas barrier resin composition layer. However, when a multilayer pipe is used as a hot water circulating pipe, such as a floor heating pipe, it is usually buried under the floor, so the risk of scratches on the gas barrier resin composition layer due to physical impact is relatively small. Therefore, from the perspective of gas barrier performance, it is preferable to arrange the gas barrier resin composition layer as the outermost layer. Gas barrier resin compositions exhibit significant humidity dependency, and their barrier properties deteriorate under high humidity conditions. Therefore, by arranging the gas barrier resin composition layer as the outermost layer, the gas barrier resin composition layer is located farthest from the inner surface of the pipe that mainly comes into contact with water, resulting in the most advantageous layer configuration in terms of barrier performance of the multilayer pipe. On the other hand, when an EVOH layer is arranged as the outermost layer, it is generally susceptible to oxidative degradation due to direct contact with air. In such an environment, when a gas barrier resin composition containing a compound having a hindered amine group and / or an antioxidant having a hindered phenol group is used, the composition is disposed in the outermost layer, which is resistant to oxidative degradation even at high temperatures, and therefore the effect of providing a multi-layer pipe that has good barrier properties while reducing the occurrence of cracks due to oxidative degradation is more effectively exerted.

[0136] Furthermore, when the multilayer pipe of the present invention is used as an insulated multilayer pipe for district heating and cooling, etc., it is preferable that the multilayer pipe have a three-layer structure of thermoplastic resin layer / adhesive resin layer / gas barrier resin composition layer, in which the gas barrier resin composition layer is arranged inside the thermoplastic resin layer (hereinafter, this may be abbreviated as laminate 1), or a five-layer structure of thermoplastic resin layer / adhesive resin layer / gas barrier resin composition layer / adhesive resin layer / thermoplastic resin layer (hereinafter, this may be abbreviated as laminate 2), from the viewpoint of preventing scratches on layer (1).

[0137] The structure of an insulated multilayer pipe for district heating and cooling, etc. is not particularly limited, but it is preferable that, for example, from the inside, an inner pipe, an insulating foam layer covering the inner pipe, and the above-mentioned laminate 1 or 2 as an outer layer are arranged in this order.

[0138] The type (material), shape, and size of the pipe used for the inner pipe are not particularly limited as long as they can transport a heat transfer medium such as gas or liquid, and can be appropriately selected depending on the type of heat transfer medium, the purpose and usage of the piping material, etc. Specific examples include metals such as steel, stainless steel, and aluminum, polyolefins (polyethylene, cross-linked polyethylene (PEX), polypropylene, poly-1-butene, poly-4-methyl-1-pentene, etc.), and the above-mentioned laminates 1 and 2, with cross-linked polyethylene (PEX) being preferred.

[0139] The insulating foam may be polyurethane foam, polyethylene foam, polystyrene foam, phenol foam, or polyisocyanurate foam, with polyurethane foam being preferred from the viewpoint of improving insulating performance.

[0140] Examples of blowing agents for insulating foams include chlorofluorocarbon gases, various chlorofluorocarbon substitutes, water, chlorinated hydrocarbons, hydrocarbons, and carbon dioxide. However, from the viewpoint of foaming effect and environmental impact, hydrocarbons, specifically n-pentane and cyclopentane, are preferred.

[0141] One example of a method for manufacturing a heat-insulating multilayer pipe is to place an inner pipe for transporting a heat transfer medium inside a pipe-shaped outer layer, fix the inner pipe with a spacer to form a double pipe, and then inject various foam concentrates into the gap between the inner pipe and the outer layer, foaming and solidifying them. The material of the spacer is not particularly limited, but polyethylene or polyurethane is preferred to reduce damage to the inner pipe and outer layer caused by the spacer.

[0142] (Manufacturing method for multi-layer pipes, etc.) A method for producing a multilayer pipe will be described below, but part or all of this method can also be applied to other molded articles (films, sheets, etc.). The multilayer pipe of the present invention can be produced, for example, by co-extrusion coating a gas barrier resin composition and an adhesive resin onto a monolayer pipe made of crosslinked polyolefin or the like, as described above. When co-extrusion coating a monolayer pipe with a gas barrier resin composition and an adhesive resin, the monolayer pipe may simply be coated with a molten film of the gas barrier resin composition and the adhesive resin. However, this may result in insufficient adhesion between the pipe and the coating layer, which may result in peeling of the coating layer during long-term use and loss of gas barrier properties. To address this issue, it is effective to flame-treat and / or corona discharge-treat the surface of the pipe to be coated before coating.

[0143] Other multilayer molding methods for producing multilayer pipes include a method using extruders in the number corresponding to the types of resin layers, and simultaneously extruding the molten resin flows in the extruders in a layered state, so-called coextrusion molding.Multilayer molding methods such as dry lamination can also be used.

[0144] The method for producing a multilayer pipe preferably includes a step of cooling with water at 10 to 70°C immediately after molding. That is, after melt molding, it is desirable to solidify the gas barrier resin composition layer by cooling with water at 10 to 70°C before the gas barrier resin composition layer solidifies. If the cooling water temperature is too low, cracks due to strain are likely to occur in the gas barrier resin composition layer at the bent portion when the multilayer pipe is bent in the subsequent secondary processing step. While the details of why strain-induced cracks are likely to occur are unclear, it is presumed that residual stress in the molded product plays a role. From this perspective, the cooling water temperature is more preferably 15°C or higher, and even more preferably 20°C or higher. On the other hand, if the cooling water temperature is too high, cracks due to strain are likely to occur in the gas barrier resin composition layer at the bent portion during secondary processing. While the details of the cause of this are not fully understood, it is presumed that this is due to excessively high crystallinity in the gas barrier resin composition layer. From this perspective, the cooling water temperature is more preferably 60°C or lower, and even more preferably 50°C or lower.

[0145] The multilayer pipe obtained by the above method can be subjected to secondary processing to obtain various molded articles. The secondary processing method is not particularly limited and any known secondary processing method can be used as appropriate, but an example is a method in which the multilayer pipe is heated to 80 to 160°C, deformed into a desired shape, and then fixed in this state for 1 minute to 2 hours.

[0146] <Thermoformed container> The thermoformed container of the present invention comprises the molded article of the present invention. The thermoformed container of the present invention may be a thermoformed container made of the molded article of the present invention. That is, one embodiment of the molded article of the present invention may be a thermoformed container. The thermoformed container of the present invention has a low environmental impact and is excellent in gas barrier properties, appearance, and molding processability. The thermoformed container of the present invention is used in various fields requiring oxygen barrier properties, such as food, cosmetics, medical and chemical drugs, and toiletries. This thermoformed container is formed to have a storage section by, for example, thermoforming a single-layer or multi-layer film or sheet.

[0147] (Storage section) The container is a portion for containing contents such as food. The shape of the container is determined according to the shape of the contents. Specifically, the thermoformed container is formed into, for example, a cup-shaped container, a tray-shaped container, a bag-shaped container, a bottle-shaped container, a pouch-shaped container, or the like.

[0148] The shape of the container can be expressed as an index by the drawing ratio (S). Here, the drawing ratio (S) is the value obtained by dividing the depth of the deepest part of the container by the diameter of the largest circle inscribed in the container opening. In other words, the larger the drawing ratio (S), the deeper the container, and the smaller the drawing ratio (S), the shallower the container. For example, if the thermoformed container is cup-shaped, the drawing ratio (S) is large, and if it is a tray, the drawing ratio (S) is small. Note that the diameter of the largest inscribed circle is, for example, the diameter of the circle if the container opening is circular, the minor axis (length of the minor axis) if it is elliptical, or the length of the short side if it is rectangular.

[0149] The preferred value of the drawing ratio (S) varies depending on the thickness of the film or sheet. When the thermoformed container is obtained by thermoforming a film, the drawing ratio (S) is preferably 0.2 or more, more preferably 0.3 or more, and even more preferably 0.4 or more. On the other hand, when the thermoformed container is obtained by molding a sheet, the drawing ratio (S) is preferably 0.3 or more, more preferably 0.5 or more, and even more preferably 0.8 or more.

[0150] In the thermoformed container, the lower limit of the thickness ratio (I / O) of the total thickness I of the other layers laminated on one side of the gas barrier resin composition layer to the total thickness O of the other layers laminated on the other side of the gas barrier resin composition layer is preferably 1 / 99, more preferably 30 / 70. The upper limit of I / O is preferably 70 / 30, more preferably 55 / 45. The thickness of all layers or a single layer of the thermoformed container is the average value of thicknesses measured by optical microscopy on samples cut out from multiple locations of the thermoformed container using a microtome.

[0151] The lower limit of the overall average thickness of the thermoformed container is preferably 300 μm, more preferably 500 μm, and even more preferably 700 μm. The upper limit of the overall average thickness of the thermoformed container is preferably 10,000 μm, more preferably 8,500 μm, and even more preferably 7,000 μm. The overall average thickness refers to the thickness of all layers in the storage section of the thermoformed container. If the overall average thickness exceeds the upper limit, the manufacturing cost of the thermoformed container increases. On the other hand, if the overall average thickness is less than the upper limit, the rigidity cannot be maintained, and the thermoformed container may easily break.

[0152] (Method for manufacturing multilayer sheets used in thermoformed containers) A method for producing a multilayer sheet, which is one of the single-layer or multilayer films used in the production of thermoformed containers, is described below. The multilayer sheet can be formed using a coextrusion molding device. For example, the gas barrier resin composition and other resins that form each layer are charged into separate extruders, and the multilayer sheet can be formed into a sheet having a predetermined layer structure by coextrusion using these extruders.

[0153] Each layer is extruded by operating an extruder equipped with a single screw at a predetermined temperature. The temperature of the extruder for forming the gas barrier resin composition layer is, for example, 170°C or higher and 260°C or lower. The temperature of the extruder for forming the thermoplastic resin layer, adhesive resin layer, and recovery layer is, for example, 150°C or higher and 260°C or lower.

[0154] (Thermoforming) The thermoformed container of the present invention can be formed by heating a multilayer sheet or the like to soften it, and then molding it into the shape of a mold. Thermoforming methods include, for example, methods of molding into the shape of a mold using vacuum or compressed air, and optionally also using a plug (straight method, drape method, air slip method, snapback method, plug assist method, etc.), and press molding. Various molding conditions such as molding temperature, degree of vacuum, compressed air pressure, and molding speed are appropriately set depending on the plug shape, mold shape, properties of the raw material resin, etc.

[0155] The molding temperature is not particularly limited as long as it is a temperature at which the resin can be softened sufficiently for molding, and the suitable temperature range varies depending on the configuration of the multilayer sheet, etc. This heating temperature is usually lower than the melting point of the resin. Specifically, the lower limit of the heating temperature for the multilayer sheet, etc. is usually 50°C, preferably 60°C, and more preferably 70°C. The upper limit of the heating temperature is, for example, 180°C, and may be 160°C.

[0156] (Layer structure of thermoformed container) The thermoformed container of the present invention is only required to have at least a gas barrier resin composition layer, and may consist of a single layer or multiple layers. When the thermoformed container has multiple layers, the layer structure may be appropriately determined depending on the intended use, etc.

[0157] When the thermoformed container of the present invention is made up of multiple layers, it is preferable that a thermoplastic resin layer is disposed as the outermost layer. If a layer made of a resin other than the gas barrier resin composition of the present invention is designated as layer x, a gas barrier resin composition layer is designated as layer y, and an adhesive resin layer is designated as layer z, then from the inside surface of the container part to the outside surface, x / z / y / z / x is preferred from the viewpoint of impact resistance. Furthermore, when a recovery layer is included, the layer configuration may be, for example: (inner surface) x / z / y / z / recovery layer / x(outer surface), (inner surface) x / recovery layer / z / y / z / recovery layer / x(outer surface), (Inner surface) Recovery layer / z / y / z / Recovery layer (outer surface) In addition, in these layer configurations, a recovery layer may be provided instead of the thermoplastic resin layer. In addition, when a plurality of x, y, z and recovery layers are used, the resins constituting each layer may be the same or different.

[0158] <Cup-shaped container> Next, the thermoformed container of the present invention will be specifically described using the cup-shaped container shown in Figures 1 and 2. However, the cup-shaped container is merely one example of a thermoformed container, and the following description of the cup-shaped container does not limit the scope of the present invention.

[0159] The cup-shaped container 1 in FIGS. 1 and 2 comprises a cup body 2 as a storage portion, and a flange portion 3. This cup-shaped container 1 is used by storing contents in the cup body 2 and sealing a lid 7 to the flange portion 3 so as to close the opening 4 of the cup body 2. Examples of the lid 7 include a resin film, a metal foil, and a metal-resin composite film. Of these, a metal-resin composite film in which a metal layer is laminated on a resin film is preferred. Examples of the resin film include a polyethylene film and a polyethylene terephthalate film. The metal layer is not particularly limited, and metal foil and a metal vapor deposition layer are preferred, with aluminum foil being more preferred from the viewpoints of gas barrier properties and productivity.

[0160] The cup-shaped container 1 is usually obtained by thermoforming a multilayer sheet. This multilayer sheet preferably includes at least a gas barrier resin composition layer, and other layers are laminated on this gas barrier resin composition layer. Examples of other layers include a thermoplastic resin layer, an adhesive resin layer, and a recovery layer. Specific examples of the layer structure of the multilayer sheet are as described above.

[0161] (Method of manufacturing a cup-shaped container) The cup-shaped container 1 is produced by heating and softening a continuous multilayer sheet 21 with a heating device 30, and then thermoforming the sheet with a mold device 40, as shown in FIG.

[0162] (heating device) The heating device 30 includes a pair of heaters (heater 31 and heater 32), and the continuous multilayer sheet 21 can pass between these heaters 31 and 32. The heating device 30 may also be one that heats by heat pressing.

[0163] (Molding equipment) The mold device 40 is suitable for thermoforming by the plug assist method and includes a lower mold 50 and an upper mold 51 housed in a chamber (not shown). The lower mold 50 and the upper mold 51 are independently movable in the vertical direction, and when they are spaced apart, the continuous multilayer sheet 21 can pass between the lower mold 50 and the upper mold 51. The lower mold 50 has a plurality of recesses 52 for forming the receiving portion of the cup-shaped container 1. The upper mold 51 has a plurality of plugs 53 protruding toward the lower mold 50. The plurality of plugs 53 are provided at positions corresponding to the plurality of recesses 52 of the lower mold 50. Each plug 53 can be inserted into the corresponding recess 52.

[0164] (Thermoforming) First, as shown in Figures 3 and 4(A), the lower mold 50 is moved upward with respect to the continuous multilayer sheet 21 softened by the heating device 30, so that the continuous multilayer sheet 21 is brought into close contact with the lower mold 50, and the continuous multilayer sheet 21 is also lifted slightly to apply tension to the continuous multilayer sheet 21. Next, as shown in Figure 4(B), the upper mold 51 is moved downward to insert the plug 53 into the recess 52.

[0165] Next, as shown in Figure 4(C), the upper mold 51 is moved upward to separate the plug 53 from the recess 52, and then the chamber (not shown) is evacuated to make the continuous multilayer sheet 21 adhere to the inner surface of the recess 52. Thereafter, the molded part is cooled by injecting air to fix the shape. Next, as shown in Figure 4(D), the chamber (not shown) is opened to the atmosphere, and the lower mold 50 is moved downward to release the lower mold 50, thereby obtaining a primary molded product. This primary molded product is cut to obtain the cup-shaped container 1 shown in Figures 1 and 2.

[0166] <Other embodiments of thermoformed containers> The thermoformed container of the present invention is not limited to the above-described forms, and tray-shaped containers are also included in the thermoformed container of the present invention. Tray-shaped containers can also be manufactured by the same method as the cup-shaped containers described above. The tray-shaped containers are suitable for use as food trays, etc.

[0167] <Blow-molded containers> The blow-molded container of the present invention comprises the molded article of the present invention. The blow-molded container of the present invention may be a blow-molded container made of the molded article of the present invention. That is, one embodiment of the molded article of the present invention may be a blow-molded container. The blow-molded container of the present invention has a low environmental impact and is also excellent in barrier properties, appearance, and moldability. The blow-molded container of the present invention can be used for various containers that require gas barrier properties, oil resistance, etc.

[0168] The blow-molded container of the present invention can have a layer structure such as, from the inner surface of the container to the outer surface of the container, (inner) x / z / y / z / recovery layer / x(outer), (inner) x / z / y / z / x(outer), (inner) x / recovery layer / z / y / z / recovery layer / x(outer), or (inner) recovery layer / z / y / z / recovery layer(outer), where x is the layer made of a resin other than the gas barrier resin composition of the present invention, y is the gas barrier resin composition layer, and z is the adhesive resin layer. Note that a recovery layer may be provided instead of the adhesive resin layer, and when a plurality of x, y, z, and recovery layers are used, the resins constituting each layer may be the same or different.

[0169] The blow-molded container of the present invention is preferably produced by a production method including a step of blow molding using a gas barrier resin composition. Blow molding can be carried out by a known method such as direct blow molding, injection blow molding, sheet blow molding, or free blow molding.

[0170] Specifically, for example, gas barrier resin composition pellets that form the gas barrier resin composition layer, and, if necessary, each resin that forms each of the other layers, are blow molded in a blow molding machine at a temperature of 100°C to 400°C, and then cooled at an internal mold temperature of 10°C to 30°C for 10 seconds to 30 minutes. This produces a blow-molded hollow container. The heating temperature during blow molding may be 150°C or higher, or may be 180°C or higher, or 200°C or higher. This heating temperature may also be the melting point of the gas barrier resin composition or higher. The upper limit of this heating temperature may be 350°C, or may be 300°C or 250°C. The blow-molded container of the present invention is used in a variety of applications, such as fuel containers and various bottles.

[0171] <Fuel container> The blow-molded container of the present invention can be used as a fuel container. The fuel container of the present invention may also include a filter, a fuel gauge, a baffle plate, and the like. By including the blow-molded container of the present invention, the fuel container of the present invention has a low environmental impact and exhibits good barrier properties, appearance, and moldability, making it suitable for use as a fuel container. Here, "fuel container" refers to a fuel container installed in an automobile, motorcycle, ship, aircraft, generator, industrial or agricultural equipment, or a portable fuel container for refueling such fuel containers, as well as a container for storing fuel. Typical examples of fuel include gasoline, particularly oxygenated gasoline blended with methanol, ethanol, or MTBE, but also heavy oil, light oil, kerosene, and the like. Of these, the fuel container of the present invention is particularly suitable for use as a fuel container for oxygenated gasoline.

[0172] <Bottle container> The blow-molded container of the present invention can be used as a bottle container. The bottle container of the present invention may further include components other than the blow-molded container of the present invention, such as a cover film or a cap. Methods for molding the bottle container of the present invention include direct blow molding and injection blow molding. The blow-molded container of the present invention molded into a bottle shape has a low environmental impact and is excellent in barrier properties, appearance, and moldability, and is therefore suitable for use as a bottle container for food, cosmetics, etc.

[0173] <Paper container> The paper container of the present invention comprises the molded article of the present invention. The paper container of the present invention may be a paper container made of the molded article of the present invention. That is, one embodiment of the molded article of the present invention may be a paper container. The paper container is made of a molded article containing a paper base material and is produced by processing into a shape such as a carton or a cup. Such a paper container is capable of storing various beverages and the like for a long period of time.

[0174] A molded article containing a paper substrate can be formed into a film at high speed by, for example, extrusion coating using a T-die method.

[0175] <Other embodiments> The present invention is not limited to the above-described embodiments. Any of the molded articles, films or sheets, packaging materials, industrial films or sheets, thermoformed containers, cup-shaped containers, tray-shaped containers, blow-molded containers, fuel containers, bottle containers, tubes, and multilayer pipes of the present invention may have, for example, a single-layer structure consisting of only a gas barrier layer formed from a gas barrier resin composition, or a multilayer structure consisting of gas barrier layers formed from a plurality of gas barrier resin compositions. [Example]

[0176] The present invention will be explained in more detail below by showing examples, but the present invention is not limited to these examples.

[0177] [Evaluation method] (1) Ethylene unit content and degree of saponification of EVOH The synthesized EVOH pellets were analyzed using dimethyl sulfoxide (DMSO)-d containing tetramethylsilane as an internal standard and tetrafluoroacetic acid (TFA) as an additive. 6 The ethylene unit content and the degree of saponification were measured at 80°C using a 500 MHz 1H-NMR (JMTC-400 / 54 / SS manufactured by JEOL Ltd.). The peaks in the spectrum measured above are assigned as follows: 0.6 to 1.9 ppm: methylene proton (4H) of ethylene unit, methylene proton (2H) of vinyl alcohol unit, methylene proton (2H) of vinyl acetate unit 1.9-2.0 ppm: methyl proton (3H) of vinyl acetate unit 3.1-4.2 ppm: methine proton (1H) of vinyl alcohol unit (2) Melting point of EVOH The synthesized EVOH pellets were heated from 30°C to 250°C at a rate of 10°C / min using a differential scanning calorimeter "Q2000" manufactured by TA Instruments, and the melting point was determined from the peak temperature measured.

[0178] (3) Determination of carboxylic acids 20 g of synthesized EVOH pellets or gas barrier resin composition pellets obtained in the Examples and Comparative Examples and 100 mL of ion-exchanged water were placed in a 200 mL Erlenmeyer flask with a stopper, a cooling condenser was attached, and stirring and extraction were carried out at 95°C for 6 hours. The obtained extract was neutralized by titration with N / 50 NaOH using phenolphthalein as an indicator, and the carboxylic acid content in terms of carboxylic acid radical was quantified. In embodiments where a phosphorus compound was contained, the carboxylic acid amount was calculated taking into account the content of the phosphorus compound measured by the evaluation method described below.

[0179] (4) Quantitative determination of metal ions, phosphate compounds, and boron compounds 0.5 g of synthesized EVOH pellets or gas barrier resin composition pellets obtained in the Examples and Comparative Examples were placed in a Teflon pressure vessel, and 5 mL of concentrated nitric acid was added and decomposed at room temperature for 30 minutes. After 30 minutes, the vessel was capped and heated in a wet decomposition apparatus (Actac's "MWS-2") at 150°C for 10 minutes and then at 180°C for 5 minutes. The vessel was then cooled to room temperature. This treatment solution was transferred to a 50 mL volumetric flask (TPX) and made up to the desired volume with purified water. Elemental analysis of this solution was performed using an ICP emission spectrometer (PerkinElmer's "OPTIMA4300DV") to determine the metal atom equivalents of metal ions, phosphorus atom equivalents of phosphorus compounds, and boron atom equivalents of boron compounds contained in the EVOH pellets or gas barrier resin composition pellets.

[0180] (5) Bio-based content The synthesized EVOH pellets and the gas barrier resin composition pellets obtained in the examples and comparative examples were analyzed for radiocarbon ( 14 The concentration of C was measured and the biobased content was calculated based on the principles of radiocarbon dating.

[0181] (6) Evaluation of monolayer films (6-1) Evaluation of defects in monolayer film A single-screw extruder ("D2020" manufactured by Toyo Seiki Seisaku-sho, Ltd.; D (mm) = 20, L / D = 20, compression ratio = 3.0, screw: full flight) was used to produce a monolayer film with an average thickness of 20 μm from the gas barrier resin composition pellets obtained in the examples and comparative examples. The conditions used were as follows: (Single screw extrusion equipment conditions) Extrusion temperature: 210℃ Screw rotation speed: 40 rpm Dice width: 30cm Take-up roll temperature: 80℃ Take-up roll speed: 3.1 m / min Monolayer films were produced by continuous operation under the above conditions, and the number of defects per 17 cm of film length was counted for each film produced 30 minutes after the start of operation. The defect count was performed using a film defect inspection device (Frontier Systems' "AI-10"). The detection camera in this film defect inspection device was installed so that its lens was 195 mm from the film surface. Film defects were judged as "good (A)" if there were fewer than 50 defects, "fairly good (B)" if there were 50 to less than 200 defects, and "poor (C)" if there were 200 or more defects.

[0182] (6-2) Evaluation of the appearance of single-layer films The film produced 30 minutes after the start of operation was visually inspected for appearance (streaks) and evaluated according to the following criteria. 100 m of film was wound around a paper tube to produce a roll, and the appearance (coloration) of the end of the roll due to yellowing was visually inspected and evaluated according to the following criteria. (Streak evaluation criteria) Good (A): No streaks were observed Fairly good (B): Streaks were observed Poor (C): Numerous streaks were observed (Evaluation criteria for coloration of roll end) Good (A): Colorless Fairly good (B): Yellowing Poor (C): Significant yellowing

[0183] (7) Oxygen permeability Using the gas barrier resin composition pellets obtained in the examples and comparative examples, a 20 μm-thick monolayer film was formed under the following conditions, and after conditioning under conditions of 20°C / 65% RH, the oxygen permeability was measured under conditions of 20°C / 65% RH using an oxygen permeability measuring device (ModernControl "OX-Tran2 / 20") The measurement was carried out in accordance with JIS K 7126-2 (constant pressure method; 2006). (Preparation of single layer film) A single-layer film having a thickness of 20 μm was produced from the gas barrier resin composition pellets using a single-screw extruder (Toyo Seiki Seisaku-sho, Ltd., "D2020", D (mm) = 20, L / D = 20, compression ratio = 3.0, screw: full flight). The extrusion conditions are as follows: Extrusion temperature: 210℃ Dice width: 30cm Take-up roll temperature: 80℃ Screw rotation speed: 40 rpm Take-up roll speed: 3.1 m / min

[0184] (8) Evaluation of multilayer films (8-1) Evaluation of multilayer film appearance Using the gas barrier resin composition pellets obtained in the Examples and Comparative Examples, a multilayer film (polyethylene layer / adhesive resin layer / gas barrier resin composition layer / adhesive resin layer / polyethylene layer, thickness (μm): 60 / 10 / 10 / 10 / 60) was produced using a three-kind five-layer co-extruder under the following conditions: Novatec™ UF943 manufactured by Japan Polyethylene Co., Ltd. was used as the polyethylene, and Admer™ NF528 manufactured by Mitsui Chemicals, Inc. was used as the adhesive resin. (Extruder conditions) Extrusion temperature for each resin: Feeding section / Compression section / Metering section / Die = 170℃ / 170℃ / 210℃ / 210℃ Polyethylene extruder: 32φ single-screw extruder, GT-32-A model (manufactured by Plastics Technology Research Institute Co., Ltd.) Adhesive resin extruder: 25φ single-screw extruder, P25-18-AC model (manufactured by Osaka Seiki Kogyo Co., Ltd.) Extruder for gas barrier resin composition: 20φ single-screw extruder, laboratory machine ME type CO-EXT (manufactured by Toyo Seiki Seisakusho Co., Ltd.) T-die: 300mm wide, 3 types, 5 layers (manufactured by Plastics Technology Research Institute Co., Ltd.) Cooling roll temperature: 50℃ Take-up speed: 4m / min The multilayer film produced 30 minutes after the start of operation was visually inspected for the presence or absence of streaks and evaluated according to the following criteria. In addition, 100 m of the multilayer film was wound around a paper tube to produce a roll, and the presence or absence of yellowing at the end of the roll was visually inspected and evaluated according to the following criteria. (Streak evaluation criteria) A (Good): No streaks were observed B (fairly good): Streaks were observed C (Poor): Many streaks were observed (Evaluation criteria for coloration of roll end) A (Good): Colorless B (fairly good): Yellowing C (poor): Significant yellowing

[0185] (8-2) Measurement of oxygen permeability The multilayer film produced in (8-1) above 30 minutes after the start of operation was conditioned at 20°C and 65% RH, and then the oxygen permeability was measured using an oxygen permeability measuring device ("OX-Tran2 / 20" from Mocon Modern Controls, Inc.) under conditions of 20°C and 65% RH in accordance with the method described in JIS K 7126-2 (isobaric method; 2006).

[0186] (9) Thermoformed container evaluation Using the gas barrier resin composition pellets obtained in the examples and comparative examples, polypropylene (Novatec™ PP EA7AD manufactured by Japan Polypropylene Corporation), and adhesive resin (Admer™ QF551 manufactured by Mitsui Chemicals, Inc.), a three-kind, five-layer co-extrusion device was used to produce a multilayer sheet (polypropylene / adhesive resin / gas barrier resin composition / adhesive resin / polypropylene, thickness (μm): 368 / 16 / 32 / 16 / 368) under the following conditions. (Extruder conditions) Extrusion temperature for each resin: Feeding section / Compression section / Metering section / Die = 150℃ / 150℃ / 210℃ / 210℃ Polypropylene resin extruder: 32φ single-screw extruder, GT-32-A model (manufactured by Plastics Technology Research Institute Co., Ltd.) Adhesive resin extruder: 25φ single-screw extruder, P25-18-AC model (manufactured by Osaka Seiki Kogyo Co., Ltd.) EVOH resin composition extruder: 20φ extruder, laboratory machine ME type CO-EXT (manufactured by Toyo Seiki Seisakusho Co., Ltd.) T-die: 300mm wide, 3 types, 5 layers (manufactured by Plastics Technology Research Institute Co., Ltd.) Cooling roll temperature: 80℃ Take-up speed: 1m / min The multilayer sheet produced 30 minutes after the start of operation was collected and the obtained multilayer sheet was heated to 160°C in a thermoforming machine (Asano Seisakusho Co., Ltd.: vacuum and compressed air deep drawing molding machine "FX-0431-3 type") and compressed air (pressure 5 kgf / cm 2 ) into a round cup shape (mold shape: upper part 75 mmφ, lower part 60 mmφ, depth 75 mm, drawing ratio S = 1.0) to obtain a thermoformed container. The molding conditions are as follows. Heater temperature: 400℃ Plug: 45φ×65mm Mold temperature: 40℃ The appearance of the resulting cup-shaped thermoformed container was visually inspected and evaluated according to the following criteria. (Appearance evaluation criteria) Good (A): No unevenness or localized thickness deviation was observed Fairly good (B): Slight unevenness and localized thickness deviation were observed. Poor (C): Significant unevenness and localized thickness deviation were observed.

[0187] (10) Streak evaluation of blow molded containers Using the EVOH resin composition pellets obtained in the Examples and Comparative Examples, high-density polyethylene ("Hizex™ 8200B" manufactured by Prime Polymer Co., Ltd.), and adhesive resin ("ADMER™ GT-6A" manufactured by Mitsui Chemicals, Inc.), a 3-type, 6-layer parison consisting of (inner) high-density polyethylene layer / adhesive resin layer / gas barrier resin composition layer / adhesive resin layer / high-density polyethylene layer / high-density polyethylene layer (outer) was blow-molded into a container at 210°C using a blow molding machine TB-ST-6P manufactured by Suzuki Seikosho Co., Ltd. Note that, in producing the blow-molded container, cooling was performed at an internal mold temperature of 15°C for 20 seconds, and a 3L blow-molded container with an average total layer thickness of 1000 μm ((inner) high-density polyethylene layer / adhesive resin layer / gas barrier resin composition layer / adhesive resin layer / high-density polyethylene layer / high-density polyethylene layer (outer) = (inner) 340 μm / 50 μm / 40 μm / 50 μm / 400 μm / 120 μm (outer)) was molded. The blow-molded containers had an average bottom diameter of 100 mm and an average height of 400 mm. 30 minutes after the start of operation, the blow-molded containers were sampled and evaluated for streaks by visually inspecting the appearance and by observing the cross section in the circumferential direction with a microscope. (Streak evaluation criteria) A (good): No streaks were observed. B (fairly good): Streaks were observed. C (Poor): Numerous streaks were observed.

[0188] (11)Fuel permeability Using the gas barrier resin composition pellets obtained in the examples and comparative examples, high-density polyethylene ("Hi-Zex (trademark) 8200B" manufactured by Prime Polymer Co., Ltd.), and an adhesive resin ("ADMER (trademark) GT-6A" of Mitsui Chemicals, Inc.), a multilayer film (polyethylene / adhesive resin / gas barrier resin composition / adhesive resin / polyethylene) was created using the three types of five-layer coextrusion equipment and extruder conditions used in (5) above. The layer structure of the multilayer film was such that the polyethylene resin in the inner and outer layers was 90 μm, the adhesive resin was 10 μm each, and the gas barrier resin composition layer in the intermediate layer was 20 μm. For the obtained multilayer film, the permeation rate of the model fuel was measured using a flow-type gas / vapor permeability measuring device (GTR-30XFKE) of GTR Tech Co., Ltd. The multilayer film was conditioned at 20 °C and 65% RH for 1 month, and the measurement was carried out at 60 °C. CE10 gasoline was used as the model fuel, and its composition was toluene / isooctane / ethanol = 45 / 45 / 10% by mass.

[0189] [Preparation of Vinyl Acetate Synthesis Catalyst] 23 g (water absorption amount 19.7 g) of silica sphere carrier HSV-I (sphere diameter 5 mm, specific surface area 160 m2 / g, water absorption rate 0.75 g / g) manufactured by Shanghai Haiyuan Chemical Technology Co., Ltd. was impregnated with an aqueous solution equivalent to the water absorption amount of the carrier containing 1.5 g of a 56% by mass aqueous solution of sodium tetrachloropalladate and 1.5 g of a 17% by mass aqueous solution of tetrachloroauric acid tetrahydrate, and then immersed in 40 mL of an aqueous solution containing 2.5 g of sodium metasilicate nonahydrate and allowed to stand for 20 hours. Subsequently, 3.3 mL of a 52% by mass aqueous solution of hydrazine hydrate was added, allowed to stand at room temperature for 4 hours, washed with water until chloride ions disappeared in the water, and dried at 110 °C for 4 hours. The obtained palladium / gold / support composition was immersed in 60 mL of a 1.7% by mass acetic acid aqueous solution and allowed to stand overnight. Then, it was washed with water overnight and dried at 110 °C for 4 hours. Thereafter, it was impregnated with an aqueous solution equivalent to the water absorption amount of the carrier of 2 g of potassium acetate and dried at 110 °C for 4 hours to obtain a vinyl acetate synthesis catalyst.

[0190] [Synthesis of Vinyl Acetate] <Synthesis Example of VAM1>[ 3 mL of the above vinyl acetate synthesis catalyst was diluted with 75 mL of glass beads and filled into a SUS316L reaction tube (inner diameter 22 mm, length 480 mm). A gas mixture of ethylene / oxygen / water / acetic acid / nitrogen = 47.3 / 6.1 / 5.6 / 26.3 / 14.7 (mol%) was passed through at a flow rate of 20 NL / h at a temperature of 150 °C and a pressure of 0.6 MPaG to conduct the reaction and synthesize vinyl acetate (VAM1). For ethylene, ethylene derived from biomass (bioethylene derived from sugarcane, manufactured by Braskem S.A.) was used, and a gas cylinder filled with this ethylene (ethylene purity 96.44%, internal volume 29.502 L, internal pressure 1.8234 MPa) was used. For acetic acid, acetic acid derived from biomass (bioacetic acid derived from sugarcane, manufactured by Godavari Biorefineries Ltd.) was used, vaporized at 220 °C, and then introduced into the reaction system by steam.

[0191] <Synthesis of VAM2 - VAM3> Vinyl acetates VAM2 - VAM3 were synthesized in the same manner as VAM1, except that the raw material ethylene and acetic acid were changed to those derived from biomass and / or fossil fuels as shown in Table 1.

[0192] The following raw materials were used as raw materials for the synthesis of vinyl acetate. · Ethylene derived from biomass: Bioethylene derived from sugarcane, manufactured by Braskem S.A. · Ethylene derived from fossil fuels: Ethylene derived from fossil fuels, manufactured by Air Liquide Industrial Gases Corporation · Acetic acid derived from biomass: Bioacetic acid derived from sugarcane, manufactured by Godavari Biorefineries Ltd. · Acetic acid derived from fossil fuels: Acetic acid derived from fossil fuels, manufactured by Fujifilm Wako Pure Chemical Corporation

[0193]

Table 1

[0194] [Synthesis of EVOH] <Preparation of EVOH (A1) pellets> (Polymerization of ethylene-vinyl acetate copolymer) A 250 L pressurized reactor equipped with a jacket, a stirrer, a nitrogen inlet, an ethylene inlet, and an initiator addition port was charged with 105 kg of VAM1 and 32.3 kg of methanol (hereinafter sometimes referred to as MeOH). The temperature was raised to 65 °C, and nitrogen bubbling was performed for 30 minutes to replace the atmosphere inside the reactor. Ethylene was then introduced at elevated pressure until the reactor pressure (ethylene pressure) reached 3.67 MPa. Biomass-derived ethylene (Braskem SA, sugarcane-derived bioethylene) was used. After adjusting the temperature inside the reactor to 65 °C, 16.8 g of 2,2'-azobis(2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd., "V-65") was added as a methanol solution to initiate polymerization. The ethylene pressure was maintained at 3.67 MPa, and the polymerization temperature was maintained at 65 °C during the polymerization. After 3 hours, when the conversion of VAc reached 45%, the polymerization was terminated by cooling. The reaction vessel was opened to remove ethylene, and then nitrogen gas was bubbled through to completely remove ethylene. Next, unreacted VAc was removed under reduced pressure, and MeOH was added to the ethylene-vinyl acetate copolymer to prepare a 20% by mass MeOH solution.

[0195] (Saponification and cleaning) 250 kg of the resulting 20% ​​by weight MeOH solution of ethylene-vinyl acetate copolymer jacket was placed in a 500 L reactor equipped with a stirrer, nitrogen inlet, reflux condenser, and solution addition port. The solution was heated to 60 °C while nitrogen was blown into it, and 4 kg of sodium hydroxide was added as a 2N MeOH solution. After the sodium hydroxide addition was completed, the system was stirred for 2 hours while maintaining the temperature at 60 °C to allow the saponification reaction to proceed. After 2 hours, 4 kg of sodium hydroxide was added again in the same manner, and heating and stirring were continued for 2 hours. Subsequently, 14 kg of acetic acid was added to terminate the saponification reaction, and 50 kg of ion-exchanged water was added. While heating and stirring, MeOH and water were distilled out of the reactor, concentrating the reaction solution. After 3 hours, an additional 50 kg of ion-exchanged water was added to precipitate EVOH. The precipitated EVOH was collected by decantation and crushed in a mixer. The obtained EVOH powder was placed in a 1 g / L aqueous acetic acid solution (bath ratio 20: 10 kg of powder per 200 L of ion-exchanged water) and washed with stirring for 2 hours. This was drained, and then placed in a 1 g / L aqueous acetic acid solution (bath ratio 20) and washed with stirring for 2 hours. The drained material was then placed in ion-exchanged water (bath ratio 20) and washed with stirring for 2 hours, followed by draining. This process was repeated three times for purification. This was dried at 60°C for 16 hours, yielding 25 kg of crude EVOH.

[0196] (Production of EVOH hydrous pellets) 25 kg of the obtained crude EVOH dry product was placed in a 100 L stirring tank equipped with a jacket, a stirrer, and a reflux condenser. Further, 20 kg of water and 20 g of MeOH were added, and the temperature was raised to 70 °C for dissolution. This solution was extruded through a glass tube with a diameter of 3 mm into a mixed solution of water / MeOH = 90 / 10 at 5 °C by weight and precipitated in a strand shape. The strand was cut into pellets with a strand cutter to obtain water-containing EVOH pellets. These water-containing EVOH pellets were put into an aqueous acetic acid solution with a concentration of 1 g / L (bath ratio 20) and stirred and washed for 2 hours. After draining the liquid, it was further put into an aqueous acetic acid solution with a concentration of 1 g / L (bath ratio 20) and stirred and washed for 2 hours. After draining the liquid, the aqueous acetic acid solution was renewed and the same operation was carried out. The product after washing with the aqueous acetic acid solution and draining the liquid was put into ion-exchanged water (bath ratio 20), and the operation of stirring and washing for 2 hours and then draining the liquid was repeated 3 times for purification, and water-containing EVOH pellets from which the catalyst residue during the saponification reaction and MeOH used during strand precipitation were removed were obtained. When the water content of the obtained water-containing EVOH pellets was measured with the halogen moisture meter "HR73" of METTLER, it was 110% by mass.

[0197] (Production of EVOH (A1) pellets) The obtained water-containing EVOH pellets were put into an aqueous solution containing sodium acetate, acetic acid, phosphoric acid, and boric acid (bath ratio 20) and immersed for 4 hours while stirring regularly. The concentration of each component was adjusted so that the content of each component in the obtained EVOH (A1) pellets was as shown in Table 2. After immersion, the liquid was drained, and drying was carried out at 80 °C for 3 hours and at 130 °C for 7.5 hours under air to obtain EVOH (A1) pellets containing sodium acetate, acetic acid, phosphoric acid, and boric acid.

[0198] (Preparation of each pellet of EVOH (A2) to EVOH (A6), EVOH (B1) to (B5)) EVOH (A2) to EVOH (A6) pellets and EVOH (B1) to EVOH (B5) pellets were produced in the same manner as EVOH (A1) pellets, except that the types of ethylene and vinyl acetate raw materials (raw material monomers) and the contents of phosphoric acid compounds and boron compounds were changed as shown in Table 2, and the amounts of ethylene and vinyl acetate used were appropriately changed. Ethylene produced by Air Liquide Kogyo Gas Co., Ltd. was used as the fossil fuel-derived ethylene.

[0199] For each of the EVOH (A1) to EVOH (A6) pellets and the EVOH (B1) to EVOH (B5) pellets, the ethylene unit content, saponification degree, melting point, carboxylic acid content, metal ions, phosphate compounds, and boron compounds, as well as the bio-based content were measured according to the methods described in the above evaluation methods (1) to (5). The results are shown in Table 2.

[0200] [Table 2]

[0201] [Example] Example 1 The EVOH (A1) pellets were extruded and pelletized under a nitrogen atmosphere using a twin-screw extruder (Toyo Seiki Seisaku-sho, Ltd., "2D25W", 25 mmφ, die temperature 220°C, screw rotation speed 100 rpm) to obtain gas barrier resin composition pellets of Example 1.

[0202] The gas barrier resin composition pellets obtained in Example 1 were subjected to measurement or evaluation of carboxylic acid quantification, metal ion quantification, phosphate compound quantification, and boron compound quantification, biobased content, monolayer film evaluation, oxygen permeability, multilayer film evaluation, streak evaluation of blow-molded containers, and fuel permeability, according to the methods described in the above evaluation methods (3) to (8), (10), and (11). The results are shown in Tables 3 and 4. The ethylene unit content and saponification degree in Table 3 are the same as those in Table 2.

[0203] <Examples 2, 4 to 6, Comparative Examples 1, 3 to 5> Gas barrier resin composition pellets of Examples 2, 4 to 6 and Comparative Examples 1, 3 to 5 were prepared and evaluated in the same manner as in Example 1, except that the type of EVOH used was changed as shown in Table 3. The results are shown in Tables 3 and 4.

[0204] <Example 3, Comparative Example 2> Gas barrier resin composition pellets of Example 3 and Comparative Example 2 were prepared in the same manner as Example 1, except that the type and mass ratio (proportion) of EVOH used was changed as shown in Table 3. Measurements or evaluations were then carried out for carboxylic acid quantification, metal ion quantification, phosphate compound quantification, and boron compound quantification, biobased content, monolayer film evaluation, oxygen permeability evaluation, multilayer film evaluation, and thermoformed container evaluation according to the methods described in the above evaluation methods (3) to (9). The results are shown in Tables 3 and 4. The ethylene unit content and saponification degree in Table 3 are the same as those in Table 2.

[0205] The gas barrier resin composition pellets obtained in Examples 1 to 6 and Comparative Examples 1 to 5 were subjected to measurement of sulfur compounds according to the method described below. The results (content and type of sulfur compounds in terms of sulfur atoms) are shown in Table 3. <Measurement of sulfur compound content> The quantitative determination of sulfur compounds was carried out using a Mitsubishi Analytech trace nitrogen and sulfur analyzer (TS-2100H type), and the measurement conditions were as follows: Heater temperature: Inlet 900℃, Outlet 900℃ Gas flow rate: Ar, O2 300 ml / min each [Analysis System NSX-2100] Measurement mode: TS Parameter: SD-210 Measurement time (timer): 540 seconds (9 minutes) PMT sensitivity: high concentration The sulfur compounds were identified using gas chromatography (GC) and gas chromatography mass spectrometry (GC / MS). The GC detector used was a flame photometric detector (FPD), which has high sensitivity to trace amounts of sulfur and phosphorus compounds. The sulfur compounds were identified by analyzing the mass components observed at the retention times at which they were detected.

[0206] Example 7 and Comparative Example 6 (Co-extrusion coated paper evaluation) The base material is carton paper (thickness 500 μm, basis weight 400 g / m 2 Coextrusion coating was performed using a three-type, five-layer structure. The coextrusion configuration was low-density polyethylene / adhesive layer / gas barrier resin composition layer / adhesive layer / low-density polyethylene / carton paper, with a thickness configuration of 20 / 5 / 5 / 5 / 20 / 500 μm. An extruder for low-density polyethylene, an extruder for EVOH, and an extruder for adhesive layer were used, along with a feed block and T-die that merged and distributed the resins supplied from each extruder. Linear low-density polyethylene (Ultzex™ 2022L, manufactured by Prime Polymer Co., Ltd.) was used as the low-density polyethylene, and maleic anhydride-modified polypropylene (Admer™ QF-500, manufactured by Mitsui Chemicals, Inc.) was used as the adhesive layer. The temperature conditions of the feed block and T-die were 250°C, and the take-up speed was 300 m / min. The coextrusion-coated paper produced 30 minutes after the start of operation was visually inspected for the presence or absence of streaks on the coextrusion-coated surface, according to the following evaluation criteria. (Streak evaluation criteria) A (Good): No streaks were observed B (fairly good): Streaks were observed C (Poor): Many streaks were observed

[0207] Co-extrusion coated paper evaluation was carried out using the gas barrier resin composition pellets of Example 5 and Comparative Example 4 as the gas barrier resin composition, and the results are shown as Example 7 and Comparative Example 6. The streak evaluation for Example 7 and Comparative Example 6 was A.

[0208] [Table 3]

[0209] [Table 4]

[0210] As shown in Tables 3 and 4, the gas barrier resin compositions of Examples 1 to 6, although made using biomass-derived raw materials, had high gas barrier properties and molding processability comparable to those made solely from fossil fuels (gas barrier resin compositions of Comparative Examples 1 to 5), suggesting that their performance was not attributable to raw materials such as biomass or fossil fuels.

[0211] Example 8 For Example 3, a traceability evaluation was performed using the thermoformed container obtained 30 minutes after the start of operation in the above-mentioned Evaluation Method (9) Thermoformed Container Evaluation. Specifically, the EVOH layer of the obtained thermoformed container was removed and used as a traceability sample. The biobased content of the removed EVOH layer was measured according to the method described in the above-mentioned Evaluation Method (5), and was found to be 100%, which matched the value obtained for the gas barrier resin composition pellets of Example 3, confirming that traceability was achieved. Furthermore, the sulfur compound content of the removed EVOH layer was measured and identified. The sulfur compound was found to be 1.2 ppm in terms of sulfur atoms, which was dimethyl sulfide, and matched the value obtained for the gas barrier resin composition pellets of Example 3, confirming that traceability was achieved. [Explanation of symbols]

[0212] 1 cup-shaped container 2 cup bodies 3 Flange 4 aperture 5 Inner surface 6 Outer surface 7 Lid 21 Continuous multi-layer sheet 30 Heating device 31,32 Heater 40 Mold equipment 50 Lower mold 51 Upper mold 52 recess 53 Plug

Claims

1. Contains a saponified ethylene-vinyl ester copolymer, the ethylene and vinyl ester that are raw materials for the saponified ethylene-vinyl ester copolymer are derived from biomass; A gas barrier resin composition containing a sulfur compound in an amount of 0.01 ppm or more and 100 ppm or less in terms of sulfur atoms.

2. 2. The gas barrier resin composition according to claim 1, wherein the saponified ethylene-vinyl ester copolymer has a biobased content of more than 99%.

3. The gas barrier resin composition according to claim 1 or 2, which has a bio-based content of more than 99%.

4. 4. The gas barrier resin composition according to claim 1, wherein the sulfur compound is dimethyl sulfide or dimethyl sulfoxide.

5. 5. The gas barrier resin composition according to claim 1, wherein the saponified ethylene-vinyl ester copolymer comprises a saponified ethylene-vinyl ester copolymer (X) and a saponified ethylene-vinyl ester copolymer (Y) having a melting point lower than that of the saponified ethylene-vinyl ester copolymer (X).

6. 6. The gas barrier resin composition according to claim 5, wherein the mass ratio (X / Y) of the saponified ethylene-vinyl ester copolymer (X) to the saponified ethylene-vinyl ester copolymer (Y) is 60 / 40 or more and 95 / 5 or less.

7. 7. The gas barrier resin composition according to claim 5, wherein the difference in melting point (X−Y) between the saponified ethylene-vinyl ester copolymer (X) and the saponified ethylene-vinyl ester copolymer (Y) is 15° C. or more.

8. 8. The gas barrier resin composition according to claim 1, which contains 30 ppm or more and 1000 ppm or less of a carboxylic acid in terms of a carboxylic acid radical.

9. The gas barrier resin composition according to any one of claims 1 to 8, which contains metal ions in an amount of 1 ppm to 1000 ppm.

10. 10. The gas barrier resin composition according to claim 1, comprising a phosphate compound in an amount of 1 ppm or more and 200 ppm or less in terms of phosphorus atoms.

11. The gas barrier resin composition according to any one of claims 1 to 10, comprising a boron compound in an amount of 5 ppm to 5,000 ppm in terms of boron atoms.

12. A molded article comprising a layer formed from the gas barrier resin composition according to any one of claims 1 to 11.

13. A molded body as described in claim 12, further comprising a thermoplastic resin layer other than the layer formed from the gas barrier resin composition.

14. A film or sheet comprising the molded article according to claim 12 or 13.

15. A packaging material comprising the film or sheet of claim 14.

16. An industrial film or sheet comprising the molded article according to claim 12 or 13.

17. A thermoformed container comprising the molded article according to claim 12 or 13.

18. A cup-shaped container comprising the thermoformed container of claim 17.

19. A tray-like container comprising the thermoformed container of claim 17.

20. A blow-molded container comprising the molded article according to claim 12 or 13.

21. A fuel container comprising the blow molded container of claim 20.

22. A bottle container comprising the blow-molded container of claim 20.

23. A tube comprising the molded article according to claim 12 or 13.

24. A multi-layer pipe comprising the molded article according to claim 12 or 13.

25. A paper container comprising the molded article according to claim 12 or 13.

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