Resin composition and layered body

Abstract

The present invention addresses the problem of providing a resin composition which comprises a polyolefin-based resin and a polyvinyl alcohol-based resin and which is less susceptible to coloration and thermal decomposition. The present invention relates to a resin composition containing (A) a polyolefin-based resin having a melting point of 90°C or higher, (B) a polyvinyl alcohol-based resin, (C) acetic acid, and (D) a thermoplastic resin having no melting point or having a melting point of less than 90°C, wherein the content ratio of acetic acid (C) based on the total amount is 50 ppm by mass or more and less than 150 ppm by mass.

Description

Resin composition and laminate

[0001] The present invention relates to resin compositions and laminates.

[0002] Conventionally, resin films made of polyamide resins, polyester resins, polyolefin resins, etc., have been used as packaging materials. For packaging materials of items whose quality deteriorates due to oxygen, such as food and beverages, pharmaceuticals, and chemicals, single resin films of the above-mentioned resins do not provide sufficient oxygen gas barrier properties. Therefore, laminates that combine materials with oxygen gas barrier properties by coating, laminating, co-extrusion molding, etc., are widely used.

[0003] As such a laminate, for example, a multilayer film produced by co-extrusion molding of a polyvinyl alcohol-based resin (hereinafter also referred to as "PVA-based resin") and a polyolefin-based resin is used (Patent Document 1). On the other hand, it is also known that a resin composition is used in which the polyvinyl alcohol-based resin and polyolefin-based resin constituting each layer of such a laminate are mixed (Patent Document 2).

[0004] Japanese Patent Publication No. 4883281 Japanese Patent Publication No. 2007-126586

[0005] As described above, multilayer films, which are constructed by laminating layers containing different resins, are useful because they can exhibit the properties of the resins contained in each layer. In recent years, instead of multilayer films in which different resins are contained in each layer, the production of films obtained from resin compositions made by mixing different resins has been investigated.

[0006] For example, when a PVA resin is added to a polyolefin resin, a resin composition can be obtained that possesses the properties of the polyolefin resin as well as the surfactant properties, mechanical properties, and gas barrier properties of the PVA resin. However, the inventors' studies have shown that the resulting resin composition may have problems originating from the PVA resin, namely, discoloration, an increase in the yellow index (hereinafter also referred to as "YI"), and a decrease in the decomposition temperature. Furthermore, it has been found that these problems can lead to a decrease in the functionality of the film obtained from the resin composition.

[0007] Therefore, the present invention aims to provide a resin composition containing a polyolefin resin and a polyvinyl alcohol resin that exhibits minimal discoloration and is resistant to thermal decomposition.

[0008] In view of these circumstances, the present inventors conducted extensive research and, as a result, discovered that a resin composition containing a polyolefin resin and a polyvinyl alcohol resin can be further enriched with a predetermined amount of acetic acid to obtain a resin composition that is less discolored and less susceptible to thermal decomposition, thus completing the present invention.

[0009] In other words, the present invention encompasses the following embodiments.

[0010] One aspect of the present invention relates to a resin composition containing a polyolefin resin (A) having a melting point of 90°C or higher, a polyvinyl alcohol resin (B), acetic acid (C), and a thermoplastic resin (D) having no melting point or a melting point of less than 90°C, wherein the content of acetic acid (C) relative to the total amount is 50 ppm by mass or more and less than 150 ppm by mass.

[0011] Aspect 2 of the present invention relates to a resin composition of Aspect 1, wherein the resin composition contains polypropylene as the polyolefin resin (A).

[0012] Aspect 3 of the present invention relates to a resin composition of aspect 1 or 2, wherein the resin composition includes a modified polyvinyl alcohol resin as the polyvinyl alcohol resin (B).

[0013] Aspect 4 of the present invention relates to a resin composition of Aspect 3, wherein the amount of modification of the modified polyvinyl alcohol-based resin is 1 to 20 mol% with respect to the vinyl alcohol units in the polyvinyl alcohol main chain.

[0014] Aspect 5 of the present invention relates to a resin composition of aspect 3 or 4, wherein the modified polyvinyl alcohol-based resin contains structural units having primary hydroxyl groups in their side chains.

[0015] Aspect 6 of the present invention relates to a resin composition in which, in any one of the resin compositions of aspects 1 to 5, the content of acetic acid (C) is less than 140 ppm by mass relative to the total amount of the resin composition.

[0016] Aspect 7 of the present invention relates to a resin composition in which, in any one of the resin compositions of aspects 1 to 6, the content of acetic acid (C) is less than 130 ppm by mass relative to the total amount of the resin composition.

[0017] Aspect 8 of the present invention relates to a resin composition in which any one of the resin compositions of aspects 1 to 7 contains 55 to 99.8% by mass of a polyolefin resin (A) based on the total amount of the resin composition.

[0018] Aspect 9 of the present invention relates to a resin composition in which any one of the resin compositions of aspects 1 to 8 contains 0.1 to 15% by mass of a polyvinyl alcohol-based resin (B) based on the total amount of the resin composition.

[0019] Aspect 10 of the present invention relates to a resin composition in any one of aspects 1 to 9, wherein the total amount of polyolefin resin (A), polyvinyl alcohol resin (B), acetic acid (C), and thermoplastic resin (D) is 55 to 100% by mass of the total amount of the resin composition.

[0020] Aspect 11 of the present invention relates to a resin composition which further contains an acid-modified polyolefin resin (E) having a melting point of 120°C or higher, in any one of the resin compositions of aspects 1 to 10.

[0021] Aspect 12 of the present invention relates to a resin composition comprising 0.1 to 15% by mass of an acid-modified polyolefin resin (E) based on the total amount of the resin composition, in any one of the resin compositions of aspects 1 to 11.

[0022] Aspect 13 of the present invention relates to a resin composition according to any one of aspects 1 to 12, wherein the thermoplastic resin (D) has a melting point of less than 90°C and a density of 0.85 to 0.95 g / cm³. ３ Acid-modified polyolefins, having a melting point of less than 90°C and a density of 0.92 to 1.05 g / cm³. ３ This invention relates to a resin composition comprising at least one selected from the group consisting of vinyl acetate copolymer resins.

[0023] Aspect 14 of the present invention relates to a resin composition according to any one of aspects 1 to 13, wherein the thermoplastic resin (D) has a melting point of less than 90°C and a density of 0.85 to 0.95 g / cm³. ３ This invention relates to a resin composition containing an acid-modified polyolefin.

[0024] Embodiment 15 of the present invention is a resin composition according to any one of embodiments 1 to 14, wherein the thermoplastic resin (D) has a melting point of less than 90°C and a density of 0.92 to 1.05 g / cm³. ３ This invention relates to a resin composition containing a vinyl acetate copolymer resin.

[0025] Embodiment 16 of the present invention relates to a resin composition in which, in any one of embodiments 1 to 15, the melting point of the polyvinyl alcohol-based resin (B) is 150 to 230°C.

[0026] Embodiment 17 of the present invention relates to a laminate having at least one layer containing the resin composition of Embodiments 1 to 16.

[0027] The present invention can provide a resin composition containing a polyolefin resin and a polyvinyl alcohol resin that exhibits minimal discoloration and is resistant to thermal decomposition.

[0028] The resin compositions according to this embodiment will be described in detail below, but these are merely examples of desirable embodiments and are not limiting. In this specification, when expressed as "X to Y" (where X and Y are any numbers), unless otherwise specified, it means "X or more and Y or less," and also includes the meaning of "preferably greater than X" or "preferably less than Y." Also, when expressed as "X or more" (where X is any number) or "Y or less" (where Y is any number), it also includes the meaning of "preferably greater than X" or "preferably less than Y." Furthermore, for numerical ranges described in stages in this specification, the upper or lower limit of a numerical range in one stage can be arbitrarily combined with the upper or lower limit of a numerical range in another stage. Also, in numerical ranges described in this specification, the upper or lower limit of that numerical range can be replaced with the values ​​shown in the examples. In this specification, unless otherwise specified, "parts" refers to "parts by mass."

[0029] The resin composition according to this embodiment contains a polyolefin resin (A) with a melting point of 90°C or higher, a polyvinyl alcohol resin (B), acetic acid (C), and a thermoplastic resin (D) that has no melting point or a melting point of less than 90°C, wherein the content of acetic acid (C) relative to the total amount is 50 ppm by mass or more and less than 150 ppm by mass.

[0030] The reason why the resin composition according to this embodiment contains a predetermined amount of acetic acid (C) results in less discoloration and reduced susceptibility to thermal decomposition is not entirely clear, but the following reasons are possible.

[0031] Because polyvinyl alcohol-based resins are hydrophilic, they easily absorb moisture unless they are packaged in completely moisture-proof packaging. When this moisture is heated and evaporates during extrusion molding, the latent heat of vaporization suppresses the rise in resin temperature due to shear heating, thus reducing the thermal history. However, since the boiling point of water is 100°C, if the resin temperature exceeds 100°C during mixing, the moisture will completely evaporate, and the resin temperature will rise. If acetic acid is added to the resin composition, since the boiling point of acetic acid is higher than that of water, the acetic acid remains in the resin even after the resin temperature exceeds 100°C, and the rise in resin temperature can be suppressed by the latent heat of vaporization. As a result, the thermal history of the resin composition is reduced, and discoloration is thought to be reduced. Also, for the same reason, the resin composition is thought to be less susceptible to thermal decomposition.

[0032] As described later, the resin composition according to this embodiment may further contain an acid-modified polyolefin resin (E) having a melting point of 120°C or higher. The preferred mass ratio of the polyolefin resin (A), polyvinyl alcohol resin (B), thermoplastic resin (D), and acid-modified polyolefin resin (E) in the resin composition is 55 to 99.8:15 to 0.1:15 to 0.1:15 to 0, and more preferably 70 to 98:10 to 0.5:10 to 0.5:10 to 1. This ratio has the advantage of less discoloration and less thermal decomposition.

[0033] In the resin composition, the polyolefin resin (A), polyvinyl alcohol resin (B), thermoplastic resin (D), and acid-modified polyolefin resin (E) are each contained as different resins.

[0034] [Polyolefin Resin (A)] In this embodiment, polyolefin resin (A) has a melting point of 90°C or higher and can be broadly defined as polyolefin resins such as polyethylene including linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), very low-density polyethylene (VLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE), ionomers, ethylene-propylene (block or random) copolymers, ethylene-acrylic acid ester copolymers, ethylene-methacrylic acid ester copolymers, polypropylene, propylene-α-olefin (α-olefin with 4 to 20 carbon atoms) copolymers, polybutene, polypentene, polymethylpentene, and other olefins, either alone or copolymers thereof, or blends thereof. Note that acid-modified polyolefin resin (E) is not included in polyolefin resin (A).

[0035] In particular, from the viewpoint of economic efficiency and mechanical properties, polyethylene or polypropylene is preferred as the polyolefin resin (A), and polypropylene is especially preferred. That is, the polyolefin resin (A) preferably contains polyethylene or polypropylene, and is especially preferred to contain polypropylene.

[0036] As for polyethylene, the density is 0.86 to 0.97 g / cm³. ３ Linear low-density polyethylene consisting of an ethylene-α-olefin copolymer is preferably used. The density is 0.86 g / cm³. ３ As a result of the above, the mechanical properties of the laminated packaging material are improved, and blocking is less likely to occur, which is preferable. Also, the density is 0.97 g / cm³. ３ The following conditions are preferable because they result in good resistance to flexural fatigue and vibration fatigue. The density referred to here is the value measured at 20°C according to JIS K7112:1999, and ethylene-α-olefin is a copolymer of ethylene and α-olefins, such as butene-1, pentene-1, 4-methylpentene-1, hexene-1, and octene-1, which typically have 18 or fewer carbon atoms. Among these, ethylene-α-olefin copolymers using olefins with 4 to 8 carbon atoms are preferably used.

[0037] As the aforementioned linear low-density polyethylene, an ethylene-α-olefin copolymer produced in the presence of a single-site catalyst is further preferred. A single-site catalyst refers to a catalyst characterized by uniform (single-site) active sites, unlike conventional multi-site catalysts such as Ziegler catalysts and Phillips catalysts which have non-uniform active sites, and typical examples thereof include metallocene-based catalysts and the like. Specific trade names of single-site catalysts include "Kernel ＴＭ " (manufactured by Nippon Polychem Co., Ltd.), "Evolue ＴＭ " (manufactured by Mitsui Chemicals, Inc.), "Exact ＴＭ " (manufactured by ExxonMobil Chemical Company), "Affinity ＴＭ " (manufactured by The Dow Chemical Company), and the like.

[0038] As the polypropylene, a polypropylene having a density of 0.87 to 0.93 g / cm ３ is preferably used. When the density is 0.87 g / cm ３ or more, various mechanical physical properties of the laminated packaging material become good, and further, blocking is less likely to occur, which is preferable. In addition, when the density is 0.93 g / cm ３ or less, flexural fatigue resistance, vibration fatigue resistance and the like are improved, which is preferable. The density referred to herein is a value measured according to JIS K7122:1999 at 20°C. Among them, a polypropylene of 0.89 to 0.91 g / cm ３ is suitably used.

[0039] The melting point of the polyolefin resin (A) is preferably 90 to 190°C, more preferably 95 to 180°C, and particularly preferably 100 to 170°C. This melting point is measured by differential scanning calorimetry (hereinafter abbreviated as "DSC") in accordance with JIS K7121:2012. In this embodiment, the melting point is measured in more detail as follows. First, the sample is heated in a nitrogen atmosphere from -60°C to 220°C at a heating rate of 10°C / min and held for 1 minute. Next, it is cooled to -60°C at a cooling rate of 10°C / min and held for 1 minute. After that, it is heated again to 220°C at a heating rate of 10°C / min. The melting point can be determined from the DSC curve obtained from the second heating. Specifically, the temperature at the minimum point of the endothermic curve is taken as the melting point. Furthermore, if a minimum point is not obtained in the DSC curve obtained during the second heating step, it is assumed that the substance does not have a melting point.

[0040] The melt flow rate (MFR) of the polyolefin resin (A) (according to JIS K7210:2014: 230°C, load 21.2 N) is preferably 0.1 to 50 g / 10 min, and more preferably 0.5 to 30 g / 10 min.

[0041] There is no particular lower limit to the content of polyolefin resin (A) in the resin composition, but from the viewpoint of moldability, it is preferable that it be 55% by mass or more, more preferably 65% ​​by mass or more, and particularly preferable 75% by mass or more, based on the total amount of the resin composition. Furthermore, there is no particular upper limit to the content of polyolefin resin (A) in the resin composition, but from the viewpoint of functionality, it is preferable that it be 99.8% by mass or less, more preferably 99% by mass or less, even more preferably 98% by mass or less, and particularly preferable 97% by mass or less, based on the total amount of the resin composition. In one embodiment, the polyolefin resin (A) can be contained in an amount of 55 to 99.8% by mass or 55 to 99% by mass based on the total amount of the resin composition.

[0042] [Polyvinyl alcohol-based resin (PVA-based resin) (B)] Generally, polyvinyl alcohol-based resins are resins obtained by saponifying a homopolymer of vinyl ester monomers, or a copolymer of vinyl ester monomers and other monomers (hereinafter, these are also referred to as "vinyl ester polymers") using an alkaline catalyst or the like. However, the polyvinyl alcohol-based resin (B) in this embodiment does not include so-called polyethylene vinyl alcohol-based resins in which the ethylene unit content relative to the total monomer is 20 mol% or more. Therefore, in polyvinyl alcohol-based resin (B), the total amount of vinyl ester monomers and other monomers other than ethylene is 80 mol% or more relative to the total monomer.

[0043] From the viewpoint of extrusion moldability, the polyvinyl alcohol-based resin (B) preferably contains a modified polyvinyl alcohol-based resin, and more preferably consists of a modified polyvinyl alcohol-based resin. A modified polyvinyl alcohol-based resin is a resin in which a modifying group is introduced by copolymerization or post-reaction to a resin mainly composed of vinyl alcohol structural units obtained by saponifying a polyvinyl ester resin obtained by polymerizing a vinyl ester compound. The modified polyvinyl alcohol-based resin consists of vinyl alcohol structural units corresponding to the degree of saponification, vinyl ester structural units that remain unsaponified, as well as unsaturated monomer structural units by copolymerization or structural units by post-reaction.

[0044] Examples of the vinyl ester compounds mentioned above include vinyl formate, vinyl acetate, vinyl trifluoroacetate, vinyl propionate, vinyl butyrate, vinyl caprate, vinyl laurylate, vinyl versaticate, vinyl palmitate, and vinyl stearate, but vinyl acetate is preferred. The vinyl ester compounds may be used alone or in combination of two or more.

[0045] Copolymerized modified polyvinyl alcohol resins (copolymerized modified polyvinyl alcohol resins) include vinyl ester monomers and unsaturated monomers copolymerizable with vinyl ester monomers, such as olefins like ethylene, propylene, isobutylene, α-octene, α-dodecene, α-octadecene; unsaturated acids like acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, their salts, monoesters, or dialkyl esters; nitriles like acrylonitrile and methacrylonitrile; amides like acrylamide and methacrylamide; olefin sulfonic acids like ethylene sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid or their salts; alkyl vinyl ethers; N-acrylamidomethyltrimethylammonium chloride, allyltrimethylammonium chloride, dimethylallyl vinyl ketone, N-vinylpyrrolidone; vinyl chloride; vinylidene chloride; and polyoxyethylene. Examples include those obtained by copolymerization with polyoxyalkylene (meth)allyl ethers such as (meth)allyl ether and polyoxypropylene (meth)allyl ether, polyoxyalkylene (meth)acrylates such as polyoxyethylene (meth)acrylate and polyoxypropylene (meth)acrylate, polyoxyalkylene (meth)acrylamides such as polyoxyethylene (meth)acrylamide and polyoxypropylene (methacrylamide), polyoxyethylene (1-(meth)acrylamide-1,1-dimethylpropyl) ester, polyoxyethylene vinyl ether, polyoxypropylene vinyl ether, polyoxyethylene allylamine, polyoxypropylene allylamine, polyoxyethylene vinylamine, polyoxypropylene vinylamine, hydroxyl group-containing α-olefins such as 3-buten-1-ol, 4-penten-1-ol, and 5-hexen-1-ol, and derivatives such as their acylated products.

[0046] The amount of modification in the modified polyvinyl alcohol resin is preferably 1 to 20 mol%, more preferably 2 to 10 mol%, and particularly preferably 3 to 8 mol%, relative to the vinyl alcohol units in the polyvinyl alcohol main chain. A modification amount of 1 mol% or more has the advantage of good extrusion moldability. Furthermore, a modification amount of 20 mol% or less has the advantage of reduced metal adhesion, improved flowability during melt molding, and reduced thermal degradation due to stagnation, etc.

[0047] Furthermore, examples of post-modified polyvinyl alcohol resins (post-modified polyvinyl alcohol resins) include those having acetoacetyl groups obtained by reaction with diketene, those having polyalkylene oxide groups obtained by reaction with ethylene oxide, those having hydroxyalkyl groups obtained by reaction with epoxy compounds, etc., or aldehyde compounds having various functional groups, obtained by reacting them with polyvinyl alcohol resins through esterification, acetalization, urethaneization, etherification, grafting, phosphate esterification, oxyalkyleneization, etc.

[0048] Furthermore, as the modified polyvinyl alcohol resin, a modified polyvinyl alcohol resin containing a structural unit with a primary hydroxyl group in its side chain is preferred, and among these, a modified polyvinyl alcohol resin containing a 1,2-diol structure is preferred, and a modified polyvinyl alcohol resin having a 1,2-diol structural unit represented by the following general formula (1) is even more preferred. In general formula (1), R １ , R ２ , and R ３ Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, X represents a single bond or a bonded chain, and R ４ , R ５ , and R ６ Each of these independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0049]

[0050] In particular, R in the 1,2-diol structural unit represented by general formula (1) １ ~R ３ , and R ４~R ６ Most preferably, the material consists entirely of hydrogen atoms and X is a single bond, and a modified polyvinyl alcohol resin having a structural unit represented by the following general formula (1') is preferably used.

[0051]

[0052] Furthermore, R in the structural unit represented by the general formula (1) １ ~R ３ , and R ４ ~R ６ Most preferably, all of these atoms are hydrogen atoms, but they may be substituted with C1-C4 alkyl groups as long as the resin properties are not significantly impaired. Examples of such C1-C4 alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl groups. These C1-C4 alkyl groups may optionally have functional groups such as halogen atoms, hydroxyl groups, ester groups, carboxylic acid groups, and sulfonic acid groups.

[0053] Furthermore, in the 1,2-diol structural unit represented by general formula (1), a single bond is most preferable for X in terms of thermal stability and stability under high temperature and acidic conditions, but a bonding chain may also be used as long as it does not hinder the effects of the present invention. Such bonding chains may include hydrocarbons such as alkylene, alkenylene, alkynylene, phenylene, and naphthylene (these hydrocarbons may be substituted with halogen atoms such as fluorine, chlorine, or bromine atoms), as well as -O-, -(CH ２ O) ｍ -, - (OCH ２ ) ｍ -, - (CH ２ O) ｍ CH ２ -, -CO-, -COCO-, -CO(CH ２ ) ｍ CO-, -CO(C ６ H ４ )CO-, -S-, -CS-, -SO-, -SO ２ -, -NR-, -CONR-, -NRCO-, -CSNR-, -NRCS-, -NRNR-, -HPO ４ -, -Si (OR) ２-, -OSi(OR) ２ -, -OSi(OR) ２ O-, -Ti (OR) ２ -, -OTi(OR) ２ -, -OTi(OR) ２ Examples include O-, -Al(OR)-, -OAl(OR)-, -OAl(OR)O-, etc. (where R is an arbitrary substituent, preferably a hydrogen atom or an alkyl group, and m is a natural number). Among these, alkylene groups with 6 or fewer carbon atoms, especially methylene groups, or -CH are preferred in terms of stability during production or use. ２ OCH ２ - is preferable.

[0054] Examples of modified polyvinyl alcohol resins containing a 1,2-diol structure include Nichigo G-Polymer. ＴＭ Examples include (manufactured by Mitsubishi Chemical Corporation), etc. Nichigo G-Polymer ＴＭ For example, this can be manufactured by the method described in paragraphs

[0026] to

[0034] of Japanese Patent Publication No. 2015-143356.

[0055] The content of 1,2-diol structural units in a modified polyvinyl alcohol resin containing a 1,2-diol structure is the same as that of a modified polyvinyl alcohol resin that has been completely saponified. １ It can be determined from the 1H-NMR spectrum (solvent: DMSO-d6, internal standard: tetramethylsilane), and specifically, it can be calculated from the peak areas derived from the hydroxyl protons, methine protons, and methylene protons in the 1,2-diol unit, the methylene proton of the main chain, and the protons of the hydroxyl group linked to the main chain.

[0056] The amount of modification in the modified polyvinyl alcohol resin containing the 1,2-diol structure is preferably 1 to 20 mol%, more preferably 2 to 10 mol%, and particularly preferably 3 to 8 mol%. A modification amount of 1 mol% or more has the advantage of good extrusion moldability. Furthermore, a modification amount of 20 mol% or less has the advantage of reduced metal adhesion, improved flowability during melt molding, and reduced thermal degradation due to stagnation, etc.

[0057] As a copolymerization method for the vinyl ester compound and an unsaturated monomer copolymerizable with the vinyl ester compound, any known polymerization method such as solution polymerization, emulsion polymerization, or suspension polymerization can be used. However, it is usually carried out by solution polymerization using an alcohol such as methanol, ethanol, or isopropyl alcohol as the solvent.

[0058] As the polymerization catalyst, known polymerization catalysts such as azo catalysts like azobisisobutyronitrile, and peroxide catalysts like acetyl peroxide, benzoyl peroxide, and lauroyl peroxide can be appropriately selected depending on the polymerization method. The polymerization reaction temperature is selected from a range of 50°C to approximately the boiling point.

[0059] Saponification can be carried out by known methods, and is usually performed by dissolving the obtained copolymer in an alcohol in the presence of a saponification catalyst. Examples of alcohols include methanol, ethanol, and butanol. The concentration of the copolymer in the alcohol is selected from a range of 20 to 50% by mass from the viewpoint of solubility.

[0060] As the saponification catalyst, alkali catalysts such as alkali metal hydroxides or alkoxides, including sodium hydroxide, potassium hydroxide, sodium methylate, sodium ethylate, and potassium methylate, can be used, and acid catalysts can also be used. The amount of saponification catalyst used is preferably 1 to 100 mmol equivalents relative to the vinyl ester compound.

[0061] The average degree of saponification of the polyvinyl alcohol-based resin (B) contained in the resin composition according to this embodiment is preferably 70 to 100 mol%, more preferably 90 to 99.9 mol%, and particularly preferably 98 to 99.8 mol%. An average degree of saponification of 70 mol% or more is preferable because it makes the polyvinyl alcohol-based resin less susceptible to thermal decomposition. The degree of saponification of the polyvinyl alcohol-based resin is a value measured in accordance with JIS K6726:1994.

[0062] The melting point of the polyvinyl alcohol-based resin (B) is preferably 150 to 230°C, more preferably 160 to 225°C, and particularly preferably 170 to 220°C. This melting point was measured by DSC in accordance with JIS K7121:2012.

[0063] There is no particular lower limit to the content of polyvinyl alcohol-based resin (B) in the resin composition, but from the viewpoint of functionality, it is preferable that it be 0.1% by mass or more, more preferably 0.3% by mass or more, and particularly preferable 0.5% by mass or more, relative to the total amount of the resin composition. Furthermore, there is no particular upper limit to the content of polyvinyl alcohol-based resin (B) in the resin composition, but from the viewpoint of moldability, it is preferable that it be 15% by mass or less, more preferably 12.5% ​​by mass or less, and particularly preferable 10% by mass or less, relative to the total amount of the resin composition. In one embodiment, the resin composition may contain 0.1 to 15% by mass of polyvinyl alcohol-based resin (B) relative to the total amount, more preferably 0.3 to 12.5% ​​by mass, and even more preferably 0.5 to 10% by mass.

[0064] [Acetic Acid (C)] The content of acetic acid (C) in the resin composition is 50 ppm by mass or more, preferably 53 ppm by mass or more, more preferably 55 ppm by mass or more, and particularly preferably 60 ppm by mass or more, based on the total amount of the resin composition.

[0065] The upper limit of the acetic acid (C) content in the resin composition is less than 150 ppm by mass, preferably less than 140 ppm by mass, more preferably less than 130 ppm by mass, and particularly preferably less than 120 ppm by mass, based on the total amount of the resin composition, from the viewpoint of preventing reaction with the hydroxyl groups of the polyvinyl alcohol-based resin (B) when the resin composition is melt-kneaded and effectively suppressing the rise in resin temperature due to the latent heat of vaporization. In one embodiment, the acetic acid (C) content in the resin composition can be 50 ppm by mass or more and less than 150 ppm by mass, 53 ppm by mass or more and less than 150 ppm by mass, 55 ppm by mass or more and less than 150 ppm by mass, 60 ppm by mass or more and less than 150 ppm by mass, 53 to 140 ppm by mass, 55 to 140 ppm by mass, 55 to 130 ppm by mass, 60 to 120 ppm by mass, etc.

[0066] The content of acetic acid (C) in the resin composition can be adjusted by the amount of acetic acid added.

[0067] Note that the acetic acid (C) content in the resin composition may be lower than the content calculated from the amount added. This is because some of the acetic acid (C) volatilizes during melt mixing and is released from the reduced pressure section (vent). In such cases, the amount of acetic acid (C) added should be increased or decreased so that the acetic acid (C) content in the resin composition falls within the desired range.

[0068] The content of acetic acid (C) in a resin composition can be measured by known methods. For example, acetic acid (C) can be extracted from the resin composition using a suitable solvent, the mass of the extracted acetic acid can be determined using a gas chromatograph-mass spectrometer (GC-MS), and the content can be determined from the relationship between the extracted acetic acid and the mass of the resin composition used.

[0069] When adding acetic acid (C) to a resin, it is preferable to add it as a mixed solution with a solvent rather than mixing it directly, in order to uniformly disperse the acetic acid (C).

[0070] Any known solvent can be used to prepare the mixed solution with acetic acid (C). Typical examples include ethanol, methanol, and propanol. Among these, ethanol and methanol are preferred.

[0071] When preparing a mixed solution of acetic acid (C) and a solvent, from the viewpoint of workability, the concentration of acetic acid (C) in the mixed solution is preferably 0.01 to 20% by mass, more preferably 0.05 to 15% by mass, and particularly preferably 0.1 to 10% by mass.

[0072] [Thermoplastic resin (D)] The thermoplastic resin (D) in this embodiment is not limited as long as it is a thermoplastic resin that has no melting point or a melting point of less than 90°C, but polyvinyl alcohol-based resin (B) is not included. Examples of thermoplastic resin (D) include acid-modified polyolefin-based resins, ethylene-vinyl acetate copolymers, and thermoplastic elastomers.

[0073] As the thermoplastic resin (D), any known acid-modified polyolefin resin may be used. Such acid-modified polyolefin resins may be selected as appropriate, but typically, modified olefin resins containing carboxyl groups, obtained by chemically bonding an unsaturated carboxylic acid or its anhydride to a polyolefin resin by addition reaction, graft reaction, etc., can be mentioned. Among these, maleic anhydride-modified polyolefins are more preferred, and maleic anhydride-graft modified polyolefins are particularly preferred.

[0074] The maleic anhydride-modified polyolefin resin is not particularly limited; for example, it may be a copolymer of α-olefin and maleic anhydride, or a polyolefin resin that has been graft-modified with maleic anhydride. Furthermore, there are no particular limitations on the method for producing the maleic anhydride-modified polyolefin resin.

[0075] The α-olefin is not particularly limited and includes, for example, ethylene, propylene, 1-butene, 1-hexene, 1-octene, vinyl acetate, vinyl benzoate and other vinyl esters, acrylic acid esters such as methyl acrylate and ethyl acrylate, methacrylic acid esters such as methyl methacrylate, ethyl methacrylate and glycidyl methacrylate, and unsaturated carboxylic acids such as acrylic acid and methacrylic acid. These may be used individually or in combination of two or more.

[0076] The density of the acid-modified polyolefin resin is preferably 0.85 to 0.95 g / cm³. ３ More preferably 0.85 to 0.94 g / cm³ ３ Particularly preferably 0.85 to 0.92 g / cm³ ３ The density was measured by DSC in accordance with JIS K7121:2012.

[0077] The vinyl acetate copolymer (EVA) used as the thermoplastic resin (D) refers to a polymer obtained by copolymerizing ethylene and vinyl acetate, and may be modified as needed.

[0078] The vinyl acetate content in EVA is preferably 1 to 60 mol%, more preferably 2 to 50 mol%, and particularly preferably 3 to 30 mol%.

[0079] The melt flow rate (MFR) of EVA (at 190°C and under a load of 2160g) is preferably 0.1 to 100g / 10min, more preferably 0.5 to 50g / 10min, and particularly preferably 1 to 30g / 10min. When the MFR is within the above range, the dispersibility with other resins when mixed with other resins tends to be good.

[0080] EVA may be a modified form containing a carboxyl group, obtained by chemically bonding an unsaturated carboxylic acid or its anhydride by an addition reaction, graft reaction, etc., to the extent that it does not impede the spirit of the present invention. The amount of such modification is preferably, for example, 10 mol% or less. Examples of the above unsaturated carboxylic acid or its anhydride include ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, and crotonic acid, as well as ethylenically unsaturated dicarboxylic acids and their anhydrides, half esters, such as fumaric acid, itaconic acid, citraconic acid, maleic acid, monomethyl maleate, monoethyl maleate, and maleic anhydride, among which maleic anhydride is preferably used.

[0081] Furthermore, EVA can be used alone, or in combination of two or more types of EVA with different ethylene content, molecular weight, MFR, density, partial saponification, modifying groups, and the degree of modification thereof. When using two or more types, it is preferable to use EVA in combination with EVA saponification with a high ethylene content, as described later.

[0082] From the viewpoint of compatibility, the thermoplastic resin (D) preferably contains an EVA saponified product with an ethylene content of 70 mol% or more (hereinafter also referred to as "high-ethylene-content EVA saponified product"). This high-ethylene-content EVA saponified product is obtained by saponifying the vinyl acetate component of EVA with an ethylene content of 70 mol% or more, and is different from EVA in that it is saponified. That is, the above EVA is an ethylene vinyl acetate copolymer that has not been saponified, while the high-ethylene-content EVA saponified product is an ethylene vinyl acetate copolymer that has been saponified. It is preferable to use the high-ethylene-content EVA saponified product together with the above EVA.

[0083] Such high-ethylene-content EVA saponified products may be modified as needed. The ethylene vinyl acetate copolymer can be produced by any known polymerization method, such as solution polymerization, suspension polymerization, emulsion polymerization, etc., and the saponification of the above-mentioned ethylene vinyl acetate copolymer can also be carried out by known methods. The ethylene content of this high-ethylene-content EVA saponified product should be 70 mol% or more, preferably 98 mol% or less, and more preferably 75 to 95 mol%, and particularly preferably 80 to 95 mol%.

[0084] Furthermore, the degree of saponification of the EVA saponide with a high ethylene content is preferably 20 mol% or more, more preferably 40 to 99.5 mol%, and particularly preferably 80 to 99 mol%.

[0085] The melt flow rate (MFR) (190°C, load 2160g) of the EVA saponide with a high ethylene content is preferably 0.5 to 100 g / 10 min, more preferably 1 to 50 g / 10 min, and particularly preferably 2 to 30 g / 10 min, as this is preferable for achieving the effects of the present invention.

[0086] EVA saponides with a high ethylene content may be modified products containing carboxyl groups obtained by chemically bonding unsaturated carboxylic acids or their anhydrides by addition reactions, graft reactions, etc., to the extent that they do not impede the spirit of the present invention. The amount of such modification is preferably, for example, 10 mol% or less. Examples of the above unsaturated carboxylic acids or their anhydrides include ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, and crotonic acid, as well as ethylenically unsaturated dicarboxylic acids and their anhydrides, half esters, such as fumaric acid, itaconic acid, citraconic acid, maleic acid, monomethyl maleate, monoethyl maleate, and maleic anhydride, among which maleic anhydride is preferably used.

[0087] High-ethylene-content EVA saponides can be used alone, or two or more high-ethylene-content EVA saponides with different ethylene content, degree of saponification, molecular weight, MFR, density, modifying groups, and their modification levels can be used in combination.

[0088] The content of EVA saponified with a high ethylene content is preferably 1 to 30 parts, more preferably 1.5 to 15 parts, and particularly preferably 2 to 10 parts, per 100 parts of EVA. In other words, having the content of EVA saponified with a high ethylene content within the above range tends to suppress the rate of eye discharge.

[0089] Furthermore, it is preferable to use at least one selected from, for example, hydrotalcites and higher fatty acid metal salts in combination with the above-mentioned EVA and the EVA saponified component with a high ethylene content in the thermoplastic resin (D) because it improves thermal stability and color suppression effect, and among these, hydrotalcites are particularly preferred due to their excellent properties.

[0090] (Hydrotalcites) Examples of hydrotalcites include hydrotalcite-based solid solutions represented by the following formula (2). [(M １ ２＋ ) ｙ１ (M ２ ２＋ ) ｙ２ ] １－ｘ M ｘ３＋ (OH) ２ A ｎ－ ｘ／ｎ ·mH ２ O ……(2) [wherein M １ ２＋ is at least one metal selected from Mg, Ca, Sr and Ba, M ２ ２＋ is at least one metal selected from Zn, Cd, Pb and Sn, M ｘ ３＋ is a trivalent metal, An- is an n-valent anion, and x, y1, y2, and m are positive numbers respectively represented by 0<x≤0.5, 0.5<y1<1, y1+y2=1, and 0≤m<2.]

[0091] In formula (2), M １ ２＋ is preferably Mg or Ca, and M ２ ２＋ is preferably Zn or Cd. Further, examples of M ｘ ３＋ include Al, Bi, In, Sb, B, Ga, Ti and the like, which may be used alone or in combination of two or more, and among them, Al is practical. Also, in the above general formula (2), A ｎ－ includes, for example, CO ３ ２－ , OH － , HCO ３ － , salicylate ion, citrate ion, tartrate ion, NO ３ － , I － , (OOC-COO) ２－ , ClO ４－ , CH ３ COO － , CO ３ ２－ , (OOCHC=CHCOO) ２－ , [Fe(CN) ６ ４－ and the like, which may be used alone or in combination of two or more, and among them, CO ３ ２－ and OH － are useful. ​

[0092] And, as a specific example of a hydrotalcite-based solid solution, [Mg ０．７５ Zn ０．２５ ] ０．６７ Al ０．３３ (OH) ２ (CO ３ ) ０．１６５・ 0.45H ２ O, [Mg ０．７９ Zn ０．２１ ] ０．７ Al ０．３ (OH) ２ (CO ３ ) ０．１５ [Mg １／７ Ca ３／７ Zn ３／７ ] ０．７ Al ０．３ (OH) ２ (OOCHC=CHCOO) ０．１５ 0.41H ２ O, [Mg ６／７ CD １／７ ] ０．７ Al ０．３ (OH) ２ (CH ３ COO) ０．３ 0.34H ２ O, [Mg ５／７ Pd ２／７ ] ０．７ Al ０．３０ (OH) ２ (CO ３ ) ０．１５ 0.52H ２ O, [Mg ０．７４ Zn ０．２６ ] ０．６８ Al ０．３２ (OH) ２ (CO ３ ) ０．１６ [Mg ０．５６ Zn ０．４４ ] ０．６８ Al ０．３２ (OH) ２ (CO ３ ) ０．１６ 0.2H ２ O, [Mg ０．８１ Zn ０．１９ ] ０．７４ Al ０．２６ (OH) ２ (CO ３ )０．１３ [Mg ０．７５ Zn ０．２５ ] ０．８ Al ０．２０ (OH) ２ (CO ３ ) ０．１０ 0.16H ２ O, [Mg ０．７１ Zn ０．２９ ] ０．７ Al ０．３０ (OH) ２ (NO ３ ) ０．３０ [Mg ０．７１ Zn ０．２９ ] ０．７ Al ０．３０ (OH) ２ (OOCHC=CHCOO) ０．１５ [Mg ０．１４ Ca ０．５７ Zn ０．２８ ] ０．７ Al ０．３０ (OH) ２．３ 0.25H ２ O is one example, and among them, [Mg ０．７５ Zn ０．２５ ] ０．６７ Al ０．３３ (OH) ２ (CO ３ ) ０．１６５ 0.45H ２ O, [Mg ０．７９ Zn ０．２１ ] ０．７ Al ０．３ (OH) ２ (CO ３ ) ０．１５ [Mg ６／７ CD １／７ ] ０．７ Al ０．３ (OH) ２ (CH ３ COO) ０．３ 0.34H ２ O, [Mg ５／７ Pd ２／７ ] ０．７ Al ０．３０ (OH)) ２ (CO ３ ) ０．１５ 0.52H ２ Examples include O.

[0093] In addition, other examples include the compound represented by the following formula (3): MxAlly(OH) ２ｘ＋３ｙ－２ｚ (E) z・aH ２ O... (3) [wherein M is Mg, Ca or Zn, E is CO ３ or HPO ４ Therefore, x, y, and z are positive numbers, and a is 0 or a positive number.

[0094] Specifically, the compound represented by formula (3) is Mg ４．５ Al ２ (OH) １３ CO ３ 3.5H ２ O, Mg ５ Al ２ (OH) １４ CO ３ 4H ２ O, Mg ６ Al ２ (OH) １６ CO ３ 4H ２ O, Mg ８ Al ２ (OH) ２０ CO ３ ・5H ２ O, Mg １０ Al ２ (OH) ２２ (CO ３ ) ２ 4H ２ O, Mg ６ Al ２ (OH) １６ HPO ４ 4H ２ O, Ca ６ Al ２ (OH) １６ CO ３ 4H ２ O, Zn ６ Al ６ (OH) １６ CO ３ 4H ２ Examples include O, etc. Furthermore, the list is not limited to the above; for example, Mg ２ Al(OH) ９ 3H ２ Some of the OH in O is CO ３ or HPO ４Even if the chemical formula is not clearly shown, such as when a substitution occurs, or even if the water of crystallization has been removed (a=0), a similar effect can be expected. In particular, among these, M is Mg and E is CO ３ The compound in question exhibits improved molding stability and suppression of mold growth, making it suitable for use.

[0095] Regarding the particle size of hydrotalcites, for example, the average particle size is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 1 μm or less. In other words, if the average particle size is too large, the effects of the present invention tend not to be fully obtained. The average particle size referred to here is the value measured by the LUZEX method.

[0096] Among hydrotalcites, it is particularly preferable to use the hydrotalcite-based solid solution represented by formula (2) above.

[0097] (Metal salts of higher fatty acids) Examples of the metal salts of higher fatty acids include alkali metal salts such as lithium, sodium, and potassium, alkaline earth metal salts such as magnesium, calcium, and barium, and transition metal salts such as zinc, copper, cobalt, iron, and manganese, of organic acids having 8 or more carbon atoms (more preferably 12 to 30 carbon atoms, and particularly preferably 12 to 20 carbon atoms). Among these, alkaline earth metal salts and transition metal salts having 12 to 20 carbon atoms are preferred in terms of their effect in suppressing eye discharge, and magnesium, calcium, and zinc salts of stearic acid, hydroxystearic acid, oleic acid, and lauric acid are particularly preferred.

[0098] The respective contents of hydrotalcites and higher fatty acid metal salts in the thermoplastic resin (D) are preferably 1 to 30 parts, more preferably 2 to 25 parts, and particularly preferably 5 to 20 parts, per 100 parts of EVA.

[0099] Furthermore, hydrotalcites and higher fatty acid metal salts can be used individually or in combination of two or more, and when two or more are used in combination, the amounts used are preferably within the above range.

[0100] The density of the ethylene vinyl acetate copolymer is preferably 0.92 to 1.05 g / cm³. ３ More preferably 0.92 to 1.04 g / cm³ ３ Particularly preferably 0.92 to 1.03 g / cm³ ３ This density was measured by DSC in accordance with JIS K7121:2012.

[0101] Examples of thermoplastic resins (D) include at least one thermoplastic elastomer selected from the group consisting of olefin-based elastomers and styrene-based elastomers.

[0102] Examples of olefin-based elastomers include ethylene-α-olefin copolymer elastomers such as ethylene-propylene copolymer elastomer (EPR), ethylene-butene copolymer elastomer (EBR), ethylene-hexene copolymer elastomer (EHR), and ethylene-octene copolymer elastomer (EOR); and ethylene-α-olefin-diene terpolymer elastomers such as ethylene-propylene-ethylidene norbornene copolymer, ethylene-propylene-butadiene copolymer, and ethylene-propylene-isoprene copolymer.

[0103] Examples of styrene-based elastomers include styrene-butadiene-styrene triblock copolymer elastomer (SBS), styrene-isoprene-styrene triblock copolymer elastomer (SIS), styrene-ethylene-butylene copolymer elastomer (SEB), styrene-ethylene-propylene copolymer elastomer (SEP), styrene-ethylene-butylene-styrene copolymer elastomer (SEBS), styrene-ethylene-butylene-ethylene copolymer elastomer (SEBC), hydrogenated styrene-butadiene elastomer (HSBR), and styrene. Examples of styrene-based elastomers include ethylene-propylene-styrene copolymer elastomer (SEPS), styrene-ethylene-ethylene-propylene-styrene copolymer elastomer (SEEPS), styrene-butadiene-butylene-styrene copolymer elastomer (SBBS), partially hydrogenated styrene-isoprene-styrene copolymer elastomer, and partially hydrogenated styrene-isoprene-butadiene-styrene copolymer elastomer, as well as hydrogenated polymer-based elastomers such as ethylene-ethylene-butylene-ethylene copolymer elastomer (CEBC).

[0104] The melting point of the thermoplastic elastomer is preferably 50°C or higher and less than 90°C, more preferably 55°C or higher and less than 90°C, and particularly preferably 60°C or higher and less than 90°C. Such melting points are measured by DSC in accordance with JIS K7121:2012.

[0105] The density of the thermoplastic elastomer is preferably 0.85 to 0.95 g / cm³. ３ More preferably 0.85 to 0.94 g / cm³ ３ Particularly preferably 0.85 to 0.92 g / cm³ ３ This density was measured by DSC in accordance with JIS K7121:2012.

[0106] The melting point of the thermoplastic resin (D) in this embodiment is preferably less than 90°C, more preferably less than 85°C, even more preferably less than 80°C, and also preferably 50°C or higher, more preferably 55°C or higher, and even more preferably 60°C or higher. In one embodiment, the melting point of the thermoplastic resin (D) in this embodiment can be 50°C or higher and less than 90°C, 55°C or higher and less than 90°C, or 60°C or higher and less than 90°C. Such melting points are measured by DSC in accordance with JIS K7121:2012.

[0107] There is no particular lower limit to the content of thermoplastic resin (D), but from the viewpoint of functionality, it is preferable that it be 0.1% by mass or more, more preferably 0.3% by mass or more, and particularly preferable 0.5% by mass or more, relative to the total amount of the resin composition. Furthermore, there is no particular upper limit to the content of thermoplastic resin (D) in the resin composition, but from the viewpoint of moldability, it is preferable that it be 15% by mass or less, more preferably 12.5% ​​by mass or less, and particularly preferable 10% by mass or less.

[0108] There is no particular lower limit to the combined content of polyolefin resin (A), polyvinyl alcohol resin (B), acetic acid (C), and thermoplastic resin (D) in the resin composition. However, from the viewpoint of functionality, it is preferable that the combined content be 55% by mass or more, more preferably 70% by mass or more, and particularly preferable 80% by mass or more, based on the total amount of the resin composition. Furthermore, there is no particular upper limit to the combined content of polyolefin resin (A), polyvinyl alcohol resin (B), acetic acid (C), and thermoplastic resin (D) in the resin composition. However, from the viewpoint of functionality, it is preferable that the combined content be 100% by mass or less, more preferably 99.9% by mass or less, even more preferably 99% by mass or less, and particularly preferable 98% by mass or less, based on the total amount of the resin composition. In one embodiment, the combined content of polyolefin resin (A), polyvinyl alcohol resin (B), acetic acid (C), and thermoplastic resin (D) can be 55 to 100% by mass, more preferably 60 to 99.9% by mass, based on the total amount of the resin composition.

[0109] The thermoplastic resin (D) preferably contains at least one selected from an acid-modified polyolefin resin, an ethylene vinyl acetate copolymer, and a thermoplastic elastomer, and preferably contains 50% by mass or more of the acid-modified polyolefin resin, ethylene vinyl acetate copolymer, or thermoplastic elastomer relative to the total amount of the thermoplastic resin (D), more preferably 65% ​​by mass or more, and even more preferably 80% by mass or more.

[0110] Furthermore, from a functional standpoint, the thermoplastic resin (D) has a melting point of less than 90°C and a density of 0.85 to 0.95 g / cm³. ３ Acid-modified polyolefins, having a melting point of less than 90°C and a density of 0.92 to 1.05 g / cm³. ３ Preferably, the material contains at least one selected from the group consisting of vinyl acetate copolymer resins. In one embodiment, the thermoplastic resin (D) has a melting point of less than 90°C and a density of 0.85 to 0.95 g / cm³. ３ This may include an acid-modified polyolefin. In another embodiment, the thermoplastic resin (D) has a melting point of less than 90°C and a density of 0.92 to 1.05 g / cm³. ３ It can contain vinyl acetate copolymer resin.

[0111] Furthermore, the thermoplastic resin (D) may also be blended with other thermoplastic resins other than the acid-modified polyolefin resin, ethylene vinyl acetate copolymer, and thermoplastic elastomer, such as polyamide resins and polyester resins, in a range that does not impair the effects of the present invention (for example, less than 30% by mass relative to the total amount of the thermoplastic resin (D)), as well as additives other than the hydrotalcite components and higher fatty acid metal salts, such as lubricants, plasticizers, heat stabilizers, light stabilizers, ultraviolet absorbers, antioxidants, nucleating agents, colorants, antistatic agents, surfactants, antibacterial agents, desiccants, oxygen absorbers, and antiblocking agents.

[0112] [Acid-modified polyolefin resin (E)] The resin composition according to this embodiment may further contain an acid-modified polyolefin resin (E) having a melting point of 120°C or higher. An acid-modified polyolefin resin is a resin in which an acid is introduced to a polyolefin resin by copolymerization or post-reaction.

[0113] As the acid-modified polyolefin resin (E), any known resin may be used. Such acid-modified polyolefin resins may be selected as appropriate, but typically, modified olefin resins containing carboxyl groups can be obtained by chemically bonding an unsaturated carboxylic acid or its anhydride to a polyolefin resin by addition reaction, graft reaction, etc. Among these, maleic anhydride-modified polyolefins are more preferred, and maleic anhydride-graft modified polyolefins are particularly preferred.

[0114] Examples of maleic anhydride-modified polyolefins include maleic anhydride-grafted polyethylene, maleic anhydride-grafted polypropylene, maleic anhydride-grafted ethylene-propylene (block and random) copolymer, and maleic anhydride-grafted ethylene-ethyl acrylate (block and random) copolymer. One or more of these selected materials are preferred.

[0115] The melting point of the acid-modified polyolefin resin (E) is preferably 120 to 190°C, more preferably 120 to 180°C, and particularly preferably 120 to 170°C. This melting point was measured by DSC in accordance with JIS K7121:2012.

[0116] The melt flow rate (MFR) (according to JIS K7210:2014: 230°C, load 21.2N) of the acid-modified polyolefin resin (E) is preferably 0.1 to 50 g / 10 min, and more preferably about 0.5 to 30 g / 10 min.

[0117] There is no particular lower limit to the content of acid-modified polyolefin resin (E) in the resin composition, but from the viewpoint of compatibility, it is preferably 0% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 1% by mass or more. Furthermore, there is no particular upper limit to the content of acid-modified polyolefin resin (E) in the resin composition, but from the viewpoint of economy, it is preferably 15% by mass or less, more preferably 12.5% ​​by mass or less, and particularly preferably 10% by mass or less. In one embodiment, the resin composition may contain 0.1 to 15% by mass of acid-modified polyolefin resin (E) relative to the total amount.

[0118] [Other Components] The resin composition according to this embodiment may further contain other components other than those described above.

[0119] Other components that can be used include, for example, antioxidants, heat stabilizers, light stabilizers, lubricants, antistatic agents, crystal nucleating agents, plasticizers, colorants, UV absorbers, surfactants, thermoplastic resins, regrinding aids, antibacterial agents, antiviral agents, desiccants, oxygen absorbers, antiblocking agents, slip agents, and inorganic / organic fillers, in order to improve moldability, physical properties, etc.

[0120] If the resin composition according to this embodiment contains other components, from the viewpoint of safety and efficacy, the content is preferably 0.01 to 10% by mass, more preferably 0.025 to 8% by mass, and particularly preferably 0.05 to 5% by mass.

[0121] [Method for producing a resin composition] A resin composition can be obtained by blending and mixing a polyolefin resin (A), a polyvinyl alcohol resin (B), acetic acid (C), and a thermoplastic resin (D), and optionally an acid-modified polyolefin resin (E) and other components. In one embodiment, a resin composition can be obtained by adding acetic acid (C) to a mixed resin containing a polyolefin resin (A), a polyvinyl alcohol resin (B), a thermoplastic resin (D), and optionally an acid-modified polyolefin resin (E), and mixing. When adding acetic acid (C) to the mixed resin, from the viewpoint of dispersibility, it is preferable to prepare a mixed solution by mixing acetic acid with a suitable solvent and add this using a spray or the like, or to impregnate the mixed resin into the mixed solution.

[0122] The resin composition obtained above can be supplied directly to the extruder for molded products, or it can be pelletized beforehand using a melt kneader such as a single-screw or twin-screw extruder using a known method, and then supplied to the extruder for molded products. The melt molding temperature during the melt extrusion described above is usually selected from the range of 150 to 300°C.

[0123] [Physical Properties of the Resin Composition] The MFR (Mold Fuel Rate) of the resin composition according to this embodiment (according to JIS K7210:2014: 230°C, load 21.2N) is preferably 0.5 to 20 g / 10 min. Having the MFR within the above range has the advantage of making it less likely for drawdown to occur during molding and making it easier to obtain a film with uniform thickness.

[0124] Furthermore, the resin composition used for the above molding process can be molded into any shape, such as films, sheets, tapes, cups, trays, tubes, bottles, pipes, filaments, extruded products with irregular cross-sections, and various irregularly shaped products.

[0125] Furthermore, in molding, heat stretching is often performed to improve the physical properties of the molded product or to mold it into any desired container shape. Here, heat stretching refers to the operation of uniformly molding a thermally heated film, sheet, or parison-shaped molded product into a cup, tray, tube, bottle, or film shape using a chuck, plug, vacuum force, compressed air, blow, etc. Examples of stretching methods include roll stretching, tenter stretching, tubular stretching, stretch blowing, vacuum forming, compressed air forming, and vacuum compressed air forming. Either uniaxial stretching or biaxial stretching may be used, but in the case of biaxial stretching, either simultaneous biaxial stretching or sequential biaxial stretching can be employed. The stretching temperature is usually 60 to 170°C, and more preferably 80 to 160°C.

[0126] In addition to the examples of molded products described above, the resin composition is generally used as at least one layer in a laminate containing it. Below, a laminate containing a layer obtained from the resin composition according to this embodiment (hereinafter also referred to as "the layer according to this embodiment") will be described in detail.

[0127] [Laminate containing the layer according to this embodiment] The laminate containing the layer according to this embodiment only needs to have at least one layer containing the above resin composition, and generally, a laminate containing a polyolefin resin layer, a PVA layer, and an adhesive resin layer as needed, in addition to the layer according to this embodiment is preferred. In this specification, "polyolefin resin layer" means a layer containing only a polyolefin resin as a resin component, "PVA layer" means a layer containing only a polyvinyl alcohol resin as a resin component, and "adhesive resin layer" means a layer containing an adhesive resin.

[0128] Specific layer configurations of a laminate containing the layer according to this embodiment include, for example, a polyolefin resin layer / layer according to this embodiment / adhesive resin layer / PVA layer, a polyolefin resin layer / layer according to this embodiment / adhesive resin layer / PVA layer / adhesive resin layer / polyolefin resin layer, a polyolefin resin layer / layer according to this embodiment / adhesive resin layer / PVA layer / adhesive resin layer / layer according to this embodiment / polyolefin resin layer, and furthermore, a layer according to this embodiment / PVA layer, and the embodiment Examples include the layer / adhesive resin layer / PVA layer according to the embodiment, the layer / adhesive resin layer / PVA layer / adhesive resin layer / PVA layer according to this embodiment, the layer / adhesive resin layer / PVA layer / adhesive resin layer / polyolefin resin layer according to this embodiment, the layer / adhesive resin layer / PVA layer / adhesive resin layer / the layer / polyolefin resin layer according to this embodiment, the polyolefin resin layer / adhesive resin layer / PVA layer / the layer / PVA layer / adhesive resin layer / polyolefin resin layer, and so on.

[0129] The thickness of each layer in a laminate containing the layers according to this embodiment cannot be generalized as it depends on the layer configuration, the type of polyolefin resin, the application, the container form, the required physical properties, etc., but the thickness of the layers according to this embodiment is preferably 1 to 5000 μm, and more preferably 5 to 1000 μm. For any layer, the thickness of the PVA layer is preferably 0.1 to 200 μm, and more preferably 0.5 to 100 μm. The thickness of the polyolefin resin layer is usually 1 to 5000 μm, and more preferably 10 to 1000 μm. In addition, the thickness of the adhesive resin layer is preferably 1 to 400 μm, and more preferably 2 to 150 μm.

[0130] Furthermore, the thickness ratio of the layer / polyolefin resin layer in this embodiment is preferably 1 / 1 to 100, and more preferably 1 / 1 to 50. Also, the thickness ratio of the layer / PVA layer in this embodiment is preferably 100 / 1 to 100, and more preferably 100 / 1 to 50.

[0131] [Method for manufacturing a laminate containing the layers according to this embodiment] As a method for manufacturing a laminate containing the layers according to this embodiment, for example, it is possible to mold it using the same type of resin as the resin composition according to this embodiment as the material and in the same manner. Specifically, it can be manufactured using the polyolefin resin used in the polyolefin resin layer exemplified above, the polyvinyl alcohol resin used in the PVA layer, and the adhesive resin used in the adhesive resin layer, by the lamination method exemplified below.

[0132] Examples of lamination methods for the above-mentioned laminate include: a method of melt-extrude-laminating the resin composition according to this embodiment onto a film or sheet of polyvinyl alcohol-based resin; a method of melt-extrude-laminating the resin composition according to this embodiment onto a substrate made of a polyolefin layer; a method of co-extruding a polyvinyl alcohol-based resin or polyolefin-based resin with the resin composition according to this embodiment; and a method of dry-laminating a film or sheet of polyvinyl alcohol-based resin or polyolefin-based resin with a film or sheet of the resin composition according to this embodiment using an adhesive such as an organic titanium compound, isocyanate compound, polyester compound, or polyurethane compound. The melt molding temperature during the above-mentioned melt extrusion is preferably in the range of 150 to 300°C.

[0133] The laminate containing the layer according to this embodiment can be used as is in various shapes, but it is also preferable to subject the laminate to a heat stretching treatment in order to further improve its physical properties and mold it into any desired container shape.

[0134] Here, heat stretching refers to the operation of uniformly shaping a thermally uniformly heated film, sheet, or parison-shaped laminate into a cup, tray, tube, bottle, or film shape using a chuck, plug, vacuum force, compressed air, blow, or the like.

[0135] The stretching methods used in the above-mentioned heat stretching process include roll stretching, tenter stretching, tubular stretching, stretch blowing, vacuum forming, pressure forming, and vacuum pressure forming. In the case of biaxial stretching, either simultaneous biaxial stretching or sequential biaxial stretching can be employed. The stretching temperature is preferably 60 to 170°C, and more preferably around 80 to 160°C. Either uniaxial stretching or biaxial stretching is acceptable, and stretching at the highest possible magnification results in better physical properties, and a stretched molded product with excellent gas barrier properties can be obtained without the occurrence of pinholes, cracks, uneven stretching, uneven thickness, or delamination during stretching.

[0136] Furthermore, each layer of the laminate obtained by this embodiment may be enriched with antioxidants, heat stabilizers, light stabilizers, lubricants, antistatic agents, nucleating agents, plasticizers, colorants, UV absorbers, surfactants, thermoplastic resins, regrinding aids, antibacterial agents, antiviral agents, desiccants, oxygen absorbers, antiblocking agents, slip agents, inorganic and organic fillers, etc., to improve moldability, physical properties, etc., within limits that do not hinder the effects of the present invention.

[0137] The laminate described above can be formed not only into sheets and films, but also into pipes, tubes, tanks, bottles, and other containers using the same molding methods as described above. Furthermore, the laminate can be reheated to approximately 60 to 170°C and stretched using the same methods as described above, such as blow stretching or deep drawing (vacuum forming, pressure forming, vacuum pressure forming, etc.), to form into bottles, tubes, cups, trays, and other containers.

[0138] Furthermore, the resulting laminate can be subjected to heat treatment, cooling treatment, rolling treatment, printing treatment, dry lamination treatment, solution or molten coating treatment, bag making, deep drawing, box making, tube making, splitting, etc., as needed.

[0139] The laminates obtained in this way are useful as containers for various products such as general foods, condiments like mayonnaise and dressings, fermented foods like miso, oily foods like salad oil, soups, beverages, cosmetics, pharmaceuticals, detergents, fragrances, industrial chemicals, pesticides, and fuels. In particular, they are useful as bottle-shaped or tube-shaped containers for semi-solid foods and condiments such as mayonnaise, ketchup, sauces, miso, wasabi, mustard, and yakiniku sauces; as well as for liquid beverages and condiments such as salad oil, mirin, sake, beer, wine, juice, tea, sports drinks, mineral water, and milk; as cup-shaped containers for semi-solid foods and condiments such as fruits, jelly, pudding, yogurt, mayonnaise, miso, processed rice, cooked foods, and soups; and as tray-shaped containers for raw meat, processed meat products (ham, bacon, wieners, etc.), cooked rice, and pet food.

[0140] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention.

[0141] First, prior to the examples, the following materials were prepared.

[0142] <Polyolefin resin (A)> Polyolefin resin (A1) Polypropylene [Density: 0.90 g / cm³] ３ MFR: 1.9 g / 10 min (measured in accordance with JIS K7210:2014), Melting point: 165°C (measured by DSC in accordance with JIS K7121:2012), Manufactured by Nippon Polypropylene Co., Ltd., Product name: Novatec ＴＭ PP FY6H]

[0143] The melting point of polyolefin resin (A1) was measured using a differential scanning calorimeter (TA Instruments, product name "DSC Q2000") according to the following 1) to 3) procedure: 1) The temperature was raised from -60°C to 220°C at a heating rate of 10°C / min and held for 1 minute. 2) The temperature was cooled to -60°C at a cooling rate of 10°C / min. 3) The temperature was raised from -60°C to 220°C at a heating rate of 10°C / min. The temperature of the endothermic peak observed during the second heating was defined as the melting point.

[0144] <Polyvinyl alcohol-based resin (PVA-based resin (B))> PVA-based resin (B1) 1,2-diol-modified polyvinyl alcohol-based resin [Degree of saponification 99 mol%, degree of polymerization 450, 1,2-diol modification 6 mol%, melting point: 188°C (measured by DSC in accordance with JIS K7121:2012)]

[0145] The melting point of the PVA-based resin (B1) was measured using the same method as that used for the polyolefin-based resin (A1).

[0146] <Thermoplastic resin (D)> Thermoplastic resin (D1) RETAIN ＴＭ 3000 (manufactured by Dow Chemical, maleic anhydride-modified polyolefin, melting point: 68°C (measured by DSC in accordance with JIS K7121:2012), density: 0.87 g / cm³) ３ The following was used: Thermoplastic resin (D2): EVA (88 parts), high-ethylene-content EVA saponified (2 parts), hydrotalcite-based solid solution (5 parts), and calcium stearate (5 parts) were mixed and melt-kneaded in a co-screw extruder to produce pellets of the target resin mixture (D2), which were then used. Melting point: 70°C (measured by DSC in accordance with JIS K7121:2012) Density: 1.00 g / cm³ ３

[0147] The melting and mixing conditions are as follows: [Melting and Mixing Conditions] ・Melting and mixing equipment: 30 mm diameter co-direction twin-screw extruder, L / D = 42 ・Setting conditions: 210°C, screw rotation speed 160 rpm, discharge rate 10 kg / hr, average mixing time of mixture 2 minutes

[0148] (EVA) Ethylene vinyl acetate copolymer [Melting point: 71°C (measured by differential scanning calorimeter according to JIS K7121:2012), vinyl acetate content: 28% by mass, MFR: 5.7 g / 10 min (190°C, load 2160 g), manufactured by Tosoh Corporation, product name "UltraSen" ＴＭ 3B53A] (EVA saponified with high ethylene content) Ethylene vinyl acetate copolymer saponified [Ethylene content: 89 mol%, degree of saponification: 99 mol%, MFR: 6.5 g / 10 min (190℃, load 2160 g), manufactured by Tosoh Corporation, product name "Mersen" ＴＭH0051K] (Hydrotalcite) Hydrotalcite-based solid solution (manufactured by Kyowa Chemical Industry Co., Ltd., product name "ZHT-4A") (Higher fatty acid metal salt) Calcium stearate (manufactured by NOF Corporation, product name "Calcium Stearate S")

[0149] The melting points of the thermoplastic resins (D1) and (D2) were measured using the same method as described above for the polyolefin resin (A1).

[0150] <Acid-modified polyolefin resin (E)> Acid-modified polyolefin resin (E1) Acid-modified polypropylene [MFR: 3.4 g / 10 min (measured in accordance with JIS K7210:2014), melting point: 141°C, measured by DSC in accordance with JIS K7121:2012), manufactured by Mitsubishi Chemical Corporation, product name "Modic ＴＭ P674V]

[0151] The melting point of the acid-modified polyolefin resin (E1) was measured using the same method as that used for the polyolefin resin (A1).

[0152] [Example 1] (Preparation of raw material composition) A mixed resin was prepared by mixing 1365 g of the above-mentioned polyolefin resin (A1), 45 g of PVA resin (B1), 45 g of thermoplastic resin (D1), and 45 g of acid-modified polyolefin resin (E1). Using a micropipette, 150 μL of acetic acid (manufactured by Wako Pure Chemical Industries, Ltd.) and 20 mL of ethanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were measured out to prepare an acetic acid / ethanol mixed solution. The raw material composition was obtained by adding the acetic acid / ethanol mixed solution using a spray while mixing the mixed resin. In Example 1, the acetic acid addition rate to the mixed resin was 100 ppm by mass.

[0153] [Example 2] (Preparation of raw material composition) A mixed resin was prepared by mixing 1365 g of the above-mentioned polyolefin resin (A1), 45 g of PVA resin (B1), 45 g of thermoplastic resin (D2), and 45 g of acid-modified polyolefin resin (E1). Using a micropipette, 750 μL of acetic acid (manufactured by Wako Pure Chemical Industries, Ltd.) and 20 mL of ethanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were measured out to prepare an acetic acid / ethanol mixed solution. The raw material composition was obtained by adding the acetic acid / ethanol mixed solution using a spray while mixing the mixed resin. In Example 2, the acetic acid addition rate to the mixed resin was 500 ppm by mass. The composition of the raw material composition is shown in Table 1 below.

[0154] (Pellet Preparation) The obtained raw material composition was fed into the hopper of a twin-screw extruder and melt-kneaded at a screw rotation speed of 250 rpm. The resin extruded from the die was placed on a belt conveyor and solidified, and then cut into pellets using a pelletizer to produce pellets of the resin compositions of Examples 1 and 2. The conditions for pellet preparation are described below.

[0155]

[0156] [Comparative Example 1] Pellets of the resin composition of Comparative Example 1 were prepared in the same manner as in Example 1, except that the amount of acetic acid in the acetic acid / ethanol mixed solution was 30 μL.

[0157] [Comparative Example 2] Pellets of the resin composition of Comparative Example 2 were prepared in the same manner as in Example 1, except that the amount of acetic acid in the acetic acid / ethanol mixed solution was 1500 μL.

[0158] [Comparative Example 3] Pellets of the resin composition of Comparative Example 3 were prepared in the same manner as in Example 2, except that an acetic acid / ethanol mixed solution was not added.

[0159] [Comparative Example 4] Pellets of the resin composition of Comparative Example 4 were prepared in the same manner as in Example 2, except that the amount of acetic acid in the acetic acid / ethanol mixed solution was 1500 μL.

[0160] <Pellet Production Conditions> ・Twin-screw extruder: TEM-18DS (manufactured by Shibaura Machinery Co., Ltd.) ・Screw size: Diameter φ20 (L / D = 40) ・Temperature setting: C1 / C2 / C3 / C4 / C5 / C6 / H = 30 / 150 / 210 / 210 / 210 / 210 / 210 (°C) ・Screen mesh: 90 / 90 ・Die: 2 holes ・Discharge rate: 4-5 kg / h

[0161] <Pellet Evaluation> The granulated pellets were evaluated using the following method. The results are shown in Table 2.

[0162] [Acetic Acid Content] The obtained pellets were finely powdered by freeze-grinding, and 2 g of the fine powder was weighed into a headspace vial. A stirring bar and 10 mL of dimethylformamide (DMF) were added to this vial, and it was sealed with a polytetrafluoroethylene (PTFE) septum-aluminum cap. The mixture was stirred at 70°C for about 1 hour to extract the acetic acid from the 2 g of pellets into the DMF layer. A certain amount of the gas phase was introduced into a gas chromatograph-mass spectrometer (GC-MS) using a headspace sampler, and the acetic acid content in the sample, i.e., the acetic acid content relative to the total amount of resin composition, was determined from the calibration curve of the standard solution. Details of the headspace sampler and GC-MS used are described below.

[0163] For the quantitative standard, acetic acid was weighed, diluted to the correct volume with DMF, and then graded to create the standard solution. 10 mL of the standard solution was taken into a headspace vial, a stirring bar was added, and the vial was sealed in the same manner as used for pellet measurement. This sample was then used as the calibration curve sample.

[0164] (Headspace Sampler) • Device: G1888 (Agilent Technologies) • Oven Temperature: 70°C • Loop Temperature: 140°C • Transfer Line Temperature: 150°C • Vial Equilibrium Time: 30 min • Loop Fill Pressure: 20 psi → 2 psi • Injection Loop Volume: 1 mL • Shaking: None

[0165] (Gas Chromatograph-Mass Spectrometer (GC-MS)) • GC Instrument: 7890B (Agilent Technologies) • MS Instrument: 5977B (Quadrupole Mass Spectrometer) (Agilent Technologies) • Column: DB-WAX 30m × 0.25mm × 0.25μm (Agilent Technologies) • Carrier Gas Type and Flow Rate: Helium, 1 mL / min • Temperature (Oven): 40°C (5 min) → Rate 10°C / min → 250°C (5 min) • Temperature (Injection): 250°C • Temperature (Auxiliary Device): Transfer Line = 250°C • Injection Mode: Split Injection Method, Split Ratio: 1 / 5 • Detector: Mass Spectrometer (Electron Multiplier Tube) • Ionization method: Electron bombardment method • Scanning range: SIM • Acetate quantitative ion (m / z 43), confirmation ion (m / z 60)

[0166] [Melt Flow Rate (MFR)] The MFR was measured in accordance with JIS K7210:2014 at a temperature of 210°C and a load of 21.2 N.

[0167] [Yellow Index (YI)] The YI of the pellets was measured using a spectrophotometer SE6000 (manufactured by Nippon Denshoku Industries Ltd.).

[0168] [Thermal Decomposition Temperature] Using a thermogravimetric analyzer TGA8000 (manufactured by PerkinElmer), the temperature at which the sample weight of 2-8 mg of a sample decreased to 90% of its weight before heating when heated to 50-550°C (10°C / min) was measured. Here, the thermal decomposition temperature represents the temperature at which the weight loss of the resin composition reaches 5% under the above conditions. A higher thermal decomposition temperature indicates that thermal decomposition is more difficult, while a lower temperature indicates that thermal decomposition is easier. When polyolefin resins undergo thermal decomposition during molding at high temperatures, they may generate toxic gases such as carbon monoxide. A higher thermal decomposition temperature indicates better thermal stability and a safer resin composition.

[0169]

[0170] The results above show that the resin composition of the present invention has a low yellow index and a high thermal decomposition temperature. This indicates that the resin composition of the present invention is less prone to discoloration and thermal decomposition.

[0171] Although various embodiments have been described above, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components in the above embodiments may be combined in any way without departing from the spirit of the invention.

[0172] This application is based on the Japanese Patent Application No. 2025-067737 filed on April 16, 2025, the contents of which are incorporated herein by reference.

[0173] The resin composition of the present invention contains a polyolefin resin (A) with a melting point of 90°C or higher, a polyvinyl alcohol resin (B), acetic acid (C), and a thermoplastic resin (D) that has no melting point or a melting point of less than 90°C, wherein the content of acetic acid (C) relative to the total amount is 50 ppm by mass or more and less than 150 ppm by mass. Due to this composition, the resin composition of the present invention can exhibit excellent effects such as low discoloration and resistance to thermal decomposition. Laminates obtained from the resin composition of the present invention are useful, for example, as containers.

Claims

1. A resin composition containing a polyolefin resin (A) having a melting point of 90°C or higher, a polyvinyl alcohol resin (B), acetic acid (C), and a thermoplastic resin (D) having no melting point or a melting point of less than 90°C, wherein the content of acetic acid (C) relative to the total amount is 50 ppm by mass or more and less than 150 ppm by mass.

2. The resin composition according to claim 1, comprising polypropylene as the polyolefin resin (A).

3. The resin composition according to claim 1 or 2, comprising a modified polyvinyl alcohol resin as the polyvinyl alcohol resin (B).

4. The resin composition according to claim 3, wherein the amount of modification of the modified polyvinyl alcohol resin is 1 to 20 mol% with respect to the vinyl alcohol units in the polyvinyl alcohol main chain.

5. The resin composition according to claim 3, wherein the modified polyvinyl alcohol-based resin contains structural units having primary hydroxyl groups in their side chains.

6. The resin composition according to claim 1 or 2, wherein the content of acetic acid (C) is less than 140 ppm by mass relative to the total amount of the resin composition.

7. The resin composition according to claim 1 or 2, wherein the content of acetic acid (C) is less than 130 ppm by mass relative to the total amount of the resin composition.

8. The resin composition according to claim 1 or 2, comprising 55 to 99.8% by mass of polyolefin resin (A) based on the total amount of the resin composition.

9. The resin composition according to claim 1 or 2, comprising 0.1 to 15% by mass of a polyvinyl alcohol-based resin (B) based on the total amount of the resin composition.

10. The resin composition according to claim 1 or 2, wherein the total amount of polyolefin resin (A), polyvinyl alcohol resin (B), acetic acid (C), and thermoplastic resin (D) is 55 to 100% by mass of the total amount of the resin composition.

11. The resin composition according to claim 1 or 2, further comprising an acid-modified polyolefin resin (E) having a melting point of 120°C or higher.

12. The resin composition according to claim 1 or 2, comprising 0.1 to 15% by mass of an acid-modified polyolefin resin (E) based on the total amount of the resin composition.

13. The thermoplastic resin (D) has a melting point of less than 90°C and a density of 0.85 to 0.95 g / cm³. ３ Acid-modified polyolefins, having a melting point of less than 90°C and a density of 0.92 to 1.05 g / cm³. ３ The resin composition according to claim 1 or 2, comprising at least one selected from the group consisting of vinyl acetate copolymer resins.

14. The thermoplastic resin (D) has a melting point of less than 90°C and a density of 0.85 to 0.95 g / cm³. ３ The resin composition according to claim 1 or 2, comprising an acid-modified polyolefin.

15. The thermoplastic resin (D) has a melting point of less than 90°C and a density of 0.92 to 1.05 g / cm³. ３ The resin composition according to claim 1 or 2, comprising a vinyl acetate copolymer resin.

16. The resin composition according to claim 1 or 2, wherein the melting point of the polyvinyl alcohol-based resin (B) is 150 to 230°C.

17. A laminate having at least one layer containing the resin composition described in claim 1 or 2.

Images