Multilayer body and multilayer container

Abstract

To provide a multilayer body which is more excellent in gas barrier property, and a multilayer container.SOLUTION: A multilayer body contains a polyamide resin layer containing a xylylenediamine-based polyamide resin as a main component, and a polyester resin layer containing a polyester resin as a main component. The polyamide resin layer contains at least one kind of halide selected from the group consisting of a halide of alkali metal and a halide of an alkali earth metal. The xylylenediamine-based polyamide resin contains a diamine-derived constitutional unit and a dicarboxylic acid-derived constitutional unit. 70 mol% or more of the diamine-derived constitutional unit is derived from xylylenediamine, and 70 mol% or more of the dicarboxylic acid-derived constitutional unit is derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a multi-layer body and a multi-layer container. [Background technology]

[0002] Conventionally, multilayer bodies and multilayer containers have been studied in which polyester resin is used as the resin constituting the outer and inner layers, and a barrier layer formed from a polyamide resin is provided between the outer and inner layers (Patent Document 1, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-169027 A [Patent Document 2] Japanese Patent Application Publication No. 60-232952 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in recent years, the demand for multilayer containers has been expanding, and there is a demand for novel multilayer bodies and multilayer containers having outer and inner layers made of polyester resins and a barrier layer (intermediate layer) made of polyamide resins. In particular, there is a demand for further improvement in gas barrier properties. The present invention has an object to solve the above problems, and to provide a multilayer body and a multilayer container having superior gas barrier properties. [Means for solving the problem]

[0005] In view of the above problems, the present inventors have conducted research and have found that the above problems can be solved by using a polyamide resin layer in which a xylylenediamine-based polyamide resin is blended with at least one kind of halide selected from the group consisting of alkali metal halides and alkaline earth metal halides. Specifically, the above problems were solved by the following means. <1> a polyamide resin layer mainly composed of a xylylenediamine-based polyamide resin; A polyester resin layer mainly composed of a polyester resin, the polyamide resin layer contains at least one kind of halide selected from the group consisting of alkali metal halides and alkaline earth metal halides, the xylylenediamine-based polyamide resin contains diamine-derived structural units and dicarboxylic acid-derived structural units, 70 mol % or more of the diamine-derived structural units are derived from xylylenediamine, and 70 mol % or more of the dicarboxylic acid-derived structural units are derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms; multilayer body. <2> The halogenide is contained in a ratio of 0.1 to 3 parts by mass relative to 100 parts by mass of the xylylenediamine-based polyamide resin. <1> The multilayer body according to claim 1. <3> The halide comprises chloride. <1> or <2> The multilayer body according to claim 1. <4> The halide comprises a magnesium halide and / or a lithium halide; <1> ~ <3> 13. The multilayer body according to any one of claims 1 to 12. <5> The molar ratio of metaxylylenediamine to paraxylylenediamine in the xylylenediamine is, when the total amount of metaxylylenediamine and paraxylylenediamine is 100 moles, metaxylylenediamine / paraxylylenediamine is 10 to 100 / 90 to 0. <1> ~ <4> 13. The multilayer body according to any one of claims 1 to 12. <6> 70 mol % or more of the dicarboxylic acid-derived structural units are structural units derived from one or more of adipic acid, sebacic acid, and dodecanedioic acid. <1> ~ <5> 13. The multilayer body according to any one of claims 1 to 12. <7> The polyester resin includes a polyethylene terephthalate resin. <1> ~ <6> 13. The multilayer body according to any one of claims 1 to 12. <8> The halogenide is contained in an amount of 0.1 to 3 parts by mass relative to 100 parts by mass of the xylylenediamine-based polyamide resin, the halide comprises chloride; the halide comprises magnesium halide and / or lithium halide; a molar ratio of metaxylylenediamine to paraxylylenediamine in the xylylenediamine is, when the total moles of metaxylylenediamine and paraxylylenediamine is 100 moles, metaxylylenediamine / paraxylylenediamine is 10 to 100 / 90 to 0; 70 mol % or more of the dicarboxylic acid-derived structural units are structural units derived from one or more of adipic acid, sebacic acid, and dodecanedioic acid, The polyester resin includes a polyethylene terephthalate resin. <1> ~ <7> 13. The multilayer body according to any one of claims 1 to 12. <9> It is stretched, <1> ~ <8> 13. The multilayer body according to any one of claims 1 to 12. <10> <1> ~ <9> A multilayer container comprising the multilayer body according to any one of claims 1 to 5. Effect of the Invention

[0006] According to the present invention, it is possible to provide a multilayer body and a multilayer container having excellent gas barrier properties. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an example of a schematic cross-sectional view of the body of a multi-layer container of this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to the present embodiment. In this specification, the use of "to" means that the numerical values ​​before and after it are included as the lower limit and upper limit. In this specification, various physical properties and characteristic values ​​are those at 23° C. unless otherwise specified. If the measurement methods, etc. described in the standards shown in this specification vary from year to year, they will be based on the standards as of January 1, 2023, unless otherwise stated. Figure 1 may not be to scale and may not correspond to reality.

[0009] The multilayer body of the present embodiment includes a polyamide resin layer (sometimes simply referred to as a "polyamide resin layer" in this specification) mainly composed of a xylylenediamine-based polyamide resin, and a polyester resin layer (sometimes simply referred to as a "polyester resin layer" in this specification) mainly composed of a polyester resin, and the polyamide resin layer includes at least one halide (sometimes simply referred to as a "halide" in this specification) selected from the group consisting of alkali metal halides and alkaline earth metal halides, and the xylylenediamine-based polyamide resin includes a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 70 mol % or more of the diamine-derived structural unit is derived from xylylenediamine, and 70 mol % or more of the dicarboxylic acid-derived structural unit is derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. By adopting such a configuration, a multilayer body having excellent gas barrier properties can be obtained. In particular, a multilayer body having excellent oxygen barrier properties and / or carbon dioxide gas barrier properties can be obtained. The reason for this is presumably that alkali metal ions such as lithium ions and alkaline earth metal ions such as magnesium ions are coordinated to the amide groups of the xylylenediamine-based polyamide resin, forming a pseudo-crosslinked structure that inhibits gas permeation. In addition, since alkali metal ions and alkaline earth metal ions have polarity, they are easily dispersed in the xylylenediamine-based polyamide resin, and it is presumed that the use of a halide makes it easier to provide the alkali metal ions and alkaline earth metal ions.

[0010] <Polyamide resin layer> The polyamide resin layer in this embodiment has a xylylenediamine-based polyamide resin as a main component and contains at least one kind of halide selected from the group consisting of alkali metal halides and alkaline earth metal halides, and the xylylenediamine-based polyamide resin contains diamine-derived structural units and dicarboxylic acid-derived structural units, with 70 mol % or more of the diamine-derived structural units being derived from xylylenediamine, and 70 mol % or more of the dicarboxylic acid-derived structural units being derived from α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms.

[0011] <<Xylylenediamine-based polyamide resin>> The polyamide resin layer used in this embodiment contains a xylylenediamine-based polyamide resin. The xylylenediamine-based polyamide resin refers to a polyamide resin that contains a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, in which 70 mol % or more of the diamine-derived structural units are derived from xylylenediamine, and 70 mol % or more of the dicarboxylic acid-derived structural units are derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. In this embodiment, there is a tendency that a multilayer body having excellent barrier properties can be obtained while maintaining the strength inherent to the xylylenediamine-based polyamide resin. The diamine-derived constitutional units of the xylylenediamine-based polyamide resin are preferably derived from xylylenediamine (preferably paraxylylenediamine and / or metaxylylenediamine, more preferably metaxylylenediamine) at 75 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, and particularly preferably 99 mol% or more. The dicarboxylic acid-derived constitutional units of the xylylenediamine-based polyamide resin are preferably derived from α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms at 75 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, and particularly preferably 99 mol% or more.

[0012] In this embodiment, the molar ratio of metaxylylenediamine and paraxylylenediamine in the xylylenediamine, when the total of metaxylylenediamine and paraxylylenediamine is 100 moles, is preferably metaxylylenediamine / paraxylylenediamine, 10 to 100 / 90 to 0, more preferably 20 to 100 / 80 to 0, even more preferably 40 to 100 / 60 to 0, even more preferably 80 to 100 / 20 to 0, and even more preferably 90 to 100 / 10 to 0. By adopting such a configuration, there is a tendency that better processability can be obtained.

[0013] Diamines other than metaxylylenediamine and paraxylylenediamine that can be used as the raw diamine component of the xylylenediamine-based polyamide resin include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine, 1,3-bis( Examples of the diamines include alicyclic diamines such as bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminomethyl)decalin, and bis(aminomethyl)tricyclodecane; and diamines having an aromatic ring such as bis(4-aminophenyl)ether, paraphenylenediamine, and bis(aminomethyl)naphthalene. These can be used alone or in combination of two or more.

[0014] In the xylylenediamine-based polyamide resin, 70 mol % or more of the dicarboxylic acid-derived constitutional units are preferably derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. The α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms preferably has 6 or more carbon atoms, and preferably has 18 or less, more preferably has 16 or less, further preferably has 14 or less, even more preferably has 13 or less, and even more preferably has 12 or less. Examples of α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms that are suitable for use as the raw dicarboxylic acid component of the xylylenediamine-based polyamide resin include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. One or a mixture of two or more of these can be used. Among these, one or more of adipic acid, sebacic acid, and dodecanedioic acid are more preferred, and adipic acid is even more preferred.

[0015] A preferred embodiment of the xylylenediamine-based polyamide resin in this embodiment is one in which 50 mol % or more (preferably 70 mol % or more, more preferably 90 mol % or more) of the dicarboxylic acid-derived structural units are derived from one or more of adipic acid, sebacic acid, and dodecanedioic acid (preferably adipic acid).

[0016] Examples of dicarboxylic acid components other than the above-mentioned α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms include phthalic acid compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, and isomers of naphthalenedicarboxylic acids such as 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. These can be used alone or in combination of two or more kinds.

[0017] In addition, the xylylenediamine-based polyamide resin is mainly composed of diamine-derived structural units and dicarboxylic acid-derived structural units, but does not completely exclude other structural units, and may contain lactams such as ε-caprolactam and laurolactam, and aliphatic aminocarboxylic acid-derived structural units such as aminocaproic acid and aminoundecanoic acid. Here, the main component means that the total number of diamine-derived structural units and dicarboxylic acid-derived structural units is the largest among all structural units among the structural units constituting the xylylenediamine-based polyamide resin. In this embodiment, the total of diamine-derived structural units and dicarboxylic acid-derived structural units in the xylylenediamine-based polyamide resin preferably accounts for 90% by mass or more of all structural units, more preferably accounts for 95% by mass or more, even more preferably accounts for 97% by mass or more, and even more preferably accounts for 99% by mass or more.

[0018] It is also preferable to use a polyamide resin produced using a biomass raw material (biomass polyamide resin) as the xylylenediamine-based polyamide resin. By using a biomass polyamide resin, it is possible to reduce the environmental load. For xylylenediamine-based polyamide resins, bio-adipic acid can be used as a biomass raw material. Mass balance certified (ISCC PLUS) adipic acid can also be used. Mass balance certification means that the amount of renewable raw materials and bio-raw materials used at each factory or production facility and the amount of products produced or shipped are quantified and guaranteed along with their quality.

[0019] The melting point of the xylylenediamine-based polyamide resin is preferably 150 to 350° C., more preferably 180 to 330° C., even more preferably 200 to 330° C., and still more preferably 200 to 320° C. When the polyamide resin layer contains two or more kinds of xylylenediamine-based polyamide resins, the melting point is the melting point of the xylylenediamine-based polyamide resin with the largest content.

[0020] In this specification, the melting point (Tm) is a value measured by differential scanning calorimetry (DSC) in accordance with ISO11357. A differential scanning calorimeter is used, and the resin is placed in the measurement pan of the differential scanning calorimeter, heated to a temperature above the melting point at a heating rate of 10°C / min under a nitrogen atmosphere, and then rapidly cooled before measurement. The measurement conditions are a heating rate of 10°C / min, held at 280°C for 5 minutes, and then cooled down to 100°C at a cooling rate of -5°C / min to determine the melting point (Tm). As the differential scanning calorimeter, a "DSC-60" manufactured by SHIMADZU CORPORATION is used.

[0021] The lower limit of the number average molecular weight (Mn) of the xylylenediamine-based polyamide resin is preferably 6,000 or more, more preferably 8,000 or more, and even more preferably 10,000 or more, and is preferably 100,000 or less, more preferably 50,000 or less. When the polyamide resin layer contains two or more kinds of xylylenediamine-based polyamide resins, the number average molecular weight is the number average molecular weight of the mixture.

[0022] The number average molecular weight (Mn) of xylylenediamine-based polyamide resin is determined by gel permeation chromatography (GPC) measurement using a standard polymethyl methacrylate (PMMA) equivalent value. Two columns packed with styrene-based polymers are used as the packing material, and hexafluoroisopropanol (HFIP) with a sodium trifluoroacetate concentration of 2 mmol / L is used as the solvent. The resin concentration is 0.02 mass%, the column temperature is 40°C, the flow rate is 0.3 mL / min, and the measurement is performed using a refractive index detector (RI). In addition, the calibration curve is measured by dissolving six levels of PMMA in HFIP.

[0023] The polyamide resin layer contains a xylylenediamine-based polyamide resin as a main component. The main component means a component that is contained in the polyamide resin layer in the largest amount. In this embodiment, the content of the xylylenediamine-based polyamide resin in the polyamide resin layer is preferably more than 50% by mass in the resin composition, more preferably 70% by mass or more, even more preferably 90% by mass or more, even more preferably 96% by mass or more, and even more preferably 98% by mass or more. The upper limit of the content of the xylylenediamine-based polyamide resin in the polyamide resin layer is an amount in which all components other than halides selected from the group consisting of alkali metal halides and alkaline earth metal halides in the resin composition are xylylenediamine-based polyamide resin. The polyamide resin layer may contain only one type of xylylenediamine-based polyamide resin, or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0024] The polyamide resin layer may or may not contain a polyamide resin other than the xylylenediamine-based polyamide resin. The other polyamide resin may be either an aliphatic polyamide resin or a semi-aromatic polyamide resin. Examples of aliphatic polyamide resins include polyamide 4, polyamide 46, polyamide 410, polyamide 6, polyamide 66, polyamide 666, polyamide 610, polyamide 11, polyamide 12, and the like. Examples of semi-aromatic polyamide resins include polyamide 4T, polyamide 6I, polyamide 6T, polyamide 6I / 6T, and polyamide 9T. In addition, as other polyamide resins that may be contained in the polyamide resin layer, the description in paragraph 0052 of JP2023-027478A can be referred to, the contents of which are incorporated herein by reference.

[0025] When the polyamide resin layer contains another polyamide resin, the content thereof is preferably 1 to 10 parts by mass with respect to 100 parts by mass of the xylylenediamine-based polyamide resin. The polyamide resin layer may be configured to be substantially free of other polyamide resins, which means that the content of other polyamide resins contained in the resin composition is less than 10% by mass, preferably less than 5% by mass, more preferably less than 3% by mass, and even more preferably less than 1% by mass.

[0026] <<Halides>> The polyamide resin layer contains at least one kind of halide selected from the group consisting of alkali metal halides and alkaline earth metal halides. By containing such a halide, a multilayer body having excellent barrier properties can be obtained. Examples of the alkali metal include lithium, sodium, potassium, rubidium, cesium, and francium, with lithium, sodium, and potassium being preferred, lithium and sodium being more preferred, and lithium being even more preferred. Examples of alkaline earth metals include beryllium, magnesium, calcium, strontium, barium, and radium, with beryllium, magnesium, and calcium being preferred, magnesium and calcium being more preferred, and magnesium being even more preferred. Examples of the halide include fluoride, chloride, bromide, and iodide, with fluoride, chloride, and iodide being preferred, fluoride and chloride being more preferred, and chloride being even more preferred.

[0027] The halide used in the present embodiment preferably contains magnesium halide and / or lithium halide, more preferably contains lithium chloride and / or magnesium chloride, and further preferably contains lithium chloride.

[0028] In this embodiment, the total content of the halide selected from the group consisting of alkali metal halides and alkaline earth metal halides is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, relative to 100 parts by mass of the xylylenediamine-based polyamide resin. By making it equal to or more than the lower limit, the gas barrier property tends to be further improved. In addition, the upper limit of the content of the halide is preferably 3 parts by mass or less, more preferably 2.5 parts by mass or less, preferably 1.8 parts by mass or less, and even more preferably 0.9 parts by mass or less, relative to 100 parts by mass of the xylylenediamine-based polyamide resin. By making it equal to or less than the upper limit, the moldability of the multilayer body or multilayer container tends to be further improved. The polyamide resin layer may contain only one kind of the halide or may contain two or more kinds of the halide. When two or more kinds are contained, the total amount is preferably within the above range.

[0029] <<Other Ingredients>> The polyamide resin layer in this embodiment may contain components other than the xylylenediamine-based polyamide resin and the halide, without departing from the spirit of the present invention. Other components may include thermoplastic resins other than xylylenediamine-based polyamide resins, inorganic fillers such as glass fibers and carbon fibers; plate-like inorganic fillers such as glass flakes, talc, kaolin, mica, montmorillonite, and organic clay; impact resistance modifiers such as various elastomers; crystal nucleating agents; lubricants such as fatty acid amide compounds and fatty acid amide compounds; antioxidants such as copper compounds, organic halogen compounds, hindered phenols, hindered amines, hydrazines, sulfur compounds, and phosphorus compounds; coloring inhibitors; ultraviolet absorbers such as benzotriazoles; additives such as release agents, plasticizers, colorants, and flame retardants; additives such as oxidation reaction accelerators, recycling aids, and compounds containing benzoquinones, anthraquinones, and naphthoquinones. The total content of these other components is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, and may be 1% by mass or less. For the oxidation reaction accelerator, reference can be made to paragraphs 0034 to 0036 of WO 2019 / 058986, the contents of which are incorporated herein by reference.

[0030] The polyamide resin other than the xylylenediamine-based polyamide resin may be an aliphatic polyamide resin or a semi-aromatic polyamide resin, and is preferably an aliphatic polyamide resin. Examples of the aliphatic polyamide resin include polyamide 6, polyamide 66, polyamide 10, polyamide 11, polyamide 12, polyamide 46, polyamide 410, polyamide 610, polyamide 612, and polyamide 666, and polyamide 6 is preferable. Examples of the semi-aromatic polyamide resin include 6T, 6T / 6I, 9T, and 9N (polycondensation product of nonanediamine and naphthalenedicarboxylic acid). These polyamide resins other than the xylylenediamine-based polyamide resin may be used alone or in combination of two or more kinds.

[0031] In this embodiment, the polyamide resin layer may or may not contain an alkali metal salt of a higher fatty acid. In the present embodiment, the content of the alkali metal salt of a higher fatty acid contained in the polyamide resin layer is preferably less than 50 ppm by mass, more preferably less than 40 ppm by mass, and even more preferably less than 30 ppm by mass, calculated as alkali metal atoms. Reducing the content of the alkali metal salt of a higher fatty acid in the polyamide resin layer has the advantage of improving the appearance of the resulting multilayer container. The alkali metal salt of a higher fatty acid is preferably a salt of a fatty acid having 12 to 30 carbon atoms. Favorable examples of fatty acids that form salts include saturated fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, and behenic acid. The alkali metal is preferably potassium or sodium.

[0032] <Polyester resin layer> The multilayer body of the present embodiment has a polyester resin layer. The polyester resin layer in the present embodiment is mainly composed of a polyester resin. Here, the term "main component" means that the polyester resin is the component with the largest content among the components contained in the polyester resin layer, and preferably 80% by mass or more of the polyester resin is polyester resin, more preferably 90% by mass or more of the polyester resin, even more preferably 95% by mass or more of the polyester resin, and even more preferably 98% by mass or more of the polyester resin. The polyester resin may contain only one type, or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0033] Examples of the polyester resin used in the present embodiment include polyethylene terephthalate resin and polybutylene terephthalate resin, with polyethylene terephthalate resin being more preferred. Polyethylene terephthalate resin is a polyester resin that contains constituent units derived from a diol and constituent units derived from a dicarboxylic acid, in which 70 mol % or more of the constituent units derived from the diol are derived from ethylene glycol, and 60 mol % or more of the constituent units derived from the dicarboxylic acid are derived from at least one selected from terephthalic acid and its esters (preferably terephthalic acid). The constituent units derived from the diol preferably derive from ethylene glycol at 85 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and even more preferably 99 mol % or more. The dicarboxylic acid-derived structural units are preferably 70 mol % or more, more preferably 80 mol % or more, and even more preferably 90 mol % or more of at least one selected from terephthalic acid and its esters. The upper limit may be 100 mol %, and is preferably 99 mol % or less.

[0034] Furthermore, in this embodiment, 60 to 99 mol% of the constitutional units derived from the dicarboxylic acid may be derived from at least one selected from terephthalic acid and its esters (preferably terephthalic acid), and 40 to 1 mol% may be derived from at least one selected from isophthalic acid and its esters (preferably isophthalic acid). By including constitutional units derived from at least one selected from isophthalic acid and its esters, crystallization of the polyester resin proceeds slowly, and solidification proceeds slowly. Therefore, the interaction with the polyamide resin contained in the polyamide resin layer becomes stronger, and the interlayer peel resistance tends to improve. Furthermore, in this embodiment, the proportion of structural units derived from at least one selected from isophthalic acid and its esters in the structural units derived from the dicarboxylic acid is preferably 20 mol % or less, more preferably 15 mol % or less, even more preferably 10 mol % or less, and even more preferably 5 mol % or less.

[0035] The polyester resin used in this embodiment may further contain other constituent units such as a constituent unit derived from 1,4-cyclohexanedimethanol as a constituent unit derived from a diol. However, in this embodiment, it is preferable that ethylene glycol accounts for preferably 85 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and even more preferably 99 mol % or more of the constituent units derived from the diol. In addition, the polyester resin used in this embodiment may further contain other structural units such as structural units derived from naphthalenedicarboxylic acid, etc. However, in this embodiment, it is preferable that 85 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and even more preferably 99 mol % or more of the structural units derived from dicarboxylic acid are terephthalic acid, isophthalic acid, and their esters (preferably terephthalic acid and isophthalic acid).

[0036] In the polyester resin in this embodiment, of all structural units excluding the terminal groups, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, even more preferably 98% by mass or more, and still more preferably 99% by mass or more are composed of structural units derived from diols and dicarboxylic acids.

[0037] The polyester resin contained in the polyester resin layer may be a crystalline polyester resin having a definite melting point, or may be an amorphous polyester resin not having a definite melting point, but is preferably a crystalline polyester resin having a melting point. The melting point of the polyester resin in the polyester resin of this embodiment is preferably 150°C or higher, more preferably 200°C or higher, and even more preferably 220°C or higher, and is preferably 300°C or lower, more preferably 290°C or lower, and even more preferably 280°C or lower. In the present embodiment, when the polyester resin layer contains two or more kinds of polyester resins, the melting point of the polyester resin is a value obtained by multiplying the melting point of each polyester resin by the mass fraction.

[0038] The intrinsic viscosity of the polyester resin is preferably 0.30 dL / g or more, more preferably 0.40 dL / g or more, and even more preferably 0.60 dL / g or more, and is preferably 2.00 dL / g or less, more preferably 1.50 dL / g or less, even more preferably 1.00 dL / g or less, and even more preferably 0.90 dL / g or less. In the present embodiment, when the polyester resin layer contains two or more polyester resins, the intrinsic viscosity refers to the intrinsic viscosity of the polyester resin mixture.

[0039] The intrinsic viscosity is measured according to the following method. Polyester resin (pellets) is dissolved in a mixed solvent of phenol / 1,1,2,2-tetrachloroethane (mass ratio 1 / 1) by stirring at 110°C for 1 hour to a concentration of 1.00 g / dL. The solution is then cooled to 30°C. The time it takes for the sample solution and the solvent alone to fall at 30°C is measured using a fully automatic solution viscometer, and the intrinsic viscosity is calculated using the following formula (1). Intrinsic viscosity=((1+4K H η sp ) 0.5 -1) / (2K H C) …(1) Here, η sp = η / η0-1, where η is the time it takes for the sample solution to fall, η0 is the time it takes for the solvent alone to fall, C is the concentration of the sample solution (g / dL), and K H is Huggins' constant. K H will be set to 0.33.

[0040] In addition to the above, examples of the polyester resin include the polyester resins described in paragraphs

[0064] to

[0080] of JP 2016-169027 A, the polyester resins described in paragraphs

[0010] to

[0021] of JP 2006-111718 A, the polyester resins described in JP 2017-105873 A, and the polyester resins described in WO 2013 / 168804 A, the contents of which are incorporated herein by reference.

[0041] The polyester resin layer of this embodiment may contain other components within the scope of this embodiment. Specifically, various additives such as antioxidants, light stabilizers, ultraviolet absorbers, plasticizers, extenders, matting agents, drying regulators, antistatic agents, antisettling agents, surfactants, flow improvers, drying oils, waxes, colorants, reinforcing agents, surface smoothing agents, leveling agents, curing reaction accelerators, and thickeners may also be added. For other components, the description in paragraph 0026 of JP 2006-111718 A may be referred to, and the contents of these are incorporated herein by reference.

[0042] <Multilayer body> Next, the multilayer body of the present embodiment will be described. The multilayer body of the present embodiment has a polyamide resin layer and a polyester resin layer. The number of layers constituting the multilayer body is preferably at least 3. In the present embodiment, an embodiment including at least two polyester resin layers and at least one polyamide resin layer is exemplified. In the multilayer body of the present embodiment, the layer formed from the polyamide resin preferably functions as a barrier layer. More specifically, the number of layers constituting the multilayer body is more preferably 3 to 10 layers, and further preferably 3 to 5 layers. In addition, the multilayer body of the present embodiment may include a gas barrier layer other than the oxygen absorbing layer, the adhesive layer, and the polyamide resin layer, a protective layer, a design layer, etc. For details of these, refer to the descriptions in paragraphs 0012 to 0046 of JP 2021-080025 A, the descriptions in JP 2017-114532 A, and the descriptions in paragraphs 0120 to 0122 of JP 2016-169291 A, the contents of which are incorporated herein by reference.

[0043] <Stretching> The multilayer body of the present embodiment is preferably stretched. The stretching may be uniaxial or biaxial stretching of a film-like multilayer body, or may be biaxial stretch blow molding carried out when forming a multilayer container such as a bottle, and biaxial stretch blow molding is preferred.

[0044] The thickness of the polyester resin and the thickness of the polyamide resin layer in the multilayer body after stretching are the same as the thickness of the polyester resin and the thickness of the polyamide resin layer in the multilayer container described below, respectively, and the preferred ranges are also the same. In the multilayer body of the present embodiment, the mass of the polyamide resin layer is preferably 1% by mass or more, more preferably 2% by mass or more, and may be 3% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less, based on the total mass of the multilayer body. By setting it to the lower limit or more, the barrier property of the multilayer body tends to be improved. Furthermore, by setting it to the upper limit or less, the transparency of the multilayer body tends to be further improved. Meanwhile, in the multilayer body of the present embodiment, the mass of the polyester resin layer is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more, based on the total mass of the multilayer body. Furthermore, in the multilayer body of the present embodiment, the mass of the polyester resin layer is preferably 99% by mass or less, more preferably 98% by mass or less, and may be 97% by mass or less, based on the total mass of the multilayer body.

[0045] <Method of manufacturing multi-layer body> The method for producing the multilayer body of the present embodiment is not particularly limited, and any known method for producing a multilayer body can be used. In manufacturing the multilayer body, it is preferable to prepare a polyester resin composition constituting the polyester resin layer and a polyamide resin composition constituting the polyamide resin layer (hereinafter, these are collectively referred to as "resin composition"). The polyamide resin composition uses at least a xylylenediamine-based polyamide resin, but when it contains other polyamide resins, there is no particular restriction on the blending method, and it may be dry-blended and supplied when making a bottle preform, or may be melt-blended using a single-screw extruder or a twin-screw extruder prior to making a preform, or a master batch may be prepared by melt-blending a part of the resins and used. In addition, when a resin additive such as an oxidation reaction accelerator is blended into the polyamide resin layer, the resin additive may be dry blended together with the xylylenediamine-based polyamide resin, or the polyamide resin or the like may be used as a masterbatch and then blended or melt blended. The same applies when the polyester resin composition contains two or more kinds of polyester resins or when it contains resin additives or the like.

[0046] As a method for producing the multi-layer body, an appropriate production method is selected taking into consideration the structure of the molded product containing the multi-layer body, etc. For example, a film or sheet can be produced by extruding a molten resin composition from an extruder through a T-die, a circular die, etc. The obtained film can also be processed into a stretched film by stretching it. Bottle-shaped packaging containers can be obtained by injecting a molten resin composition from an injection molding machine into a mold to produce a preform, followed by blow stretching (injection blow molding, injection stretch blow molding), or by extruding a molten resin composition from an extrusion molding machine into a mold to obtain a parison, which is then blown in the mold (direct blow molding). Containers such as trays and cups can be produced by injecting a molten resin composition into a mold from an injection molding machine, or by forming a sheet using a forming method such as vacuum forming or pressure forming.

[0047] The multi-layer container of the present embodiment is preferably produced by biaxially stretching and blow molding a preform. The multi-layer container of the present embodiment may be produced by cold parison molding or hot parison molding.

[0048] <Multilayer container> In this embodiment, a multilayer container including the multilayer body of this embodiment is exemplified. The multilayer container of this embodiment has a polyester resin layer and a polyamide resin layer. Usually, the polyester resin layer is on the outside. Furthermore, the multilayer container of this embodiment preferably has a three-layer structure of polyester resin layer / polyamide resin layer / polyester resin layer. Specifically, as illustrated in FIG. 1, the cross section of the body of the multilayer container preferably has a polyester resin layer 1, a polyamide resin layer 2, and a polyester resin layer 3 in that order from the outside. More preferably, the polyester resin layer 1 and the polyamide resin layer 2 are in contact with each other directly or through an adhesive layer in a plane direction perpendicular to the cross section of the body, and the polyamide resin layer 2 and the polyester resin layer 3 are also in contact with each other directly or through an adhesive layer in a plane direction perpendicular to the cross section of the body. The thickness in FIG. 1 is not necessarily proportional to the actual thickness. In the multilayer container of the present embodiment, the portions other than the body portion, such as the bottom portion, preferably have the three-layer structure of polyester resin layer / polyamide resin layer / polyester resin layer, but this is not necessarily required. In this case, the two polyester resin layers may be polyester resin layers having the same composition, or may be polyester resin layers having different compositions. Furthermore, the multilayer container of this embodiment may include a gas barrier layer other than the oxygen absorbing layer, the adhesive layer, and the polyamide resin layer, a protective layer, a design layer, etc. For details of these, refer to the descriptions in paragraphs 0012 to 0046 of JP 2021-080025 A, the descriptions in JP 2017-114532 A, and the descriptions in paragraphs 0120 to 0122 of JP 2016-169291 A, the contents of which are incorporated herein by reference.

[0049] The shape of the multilayer container is not particularly limited, and may be, for example, a molded container such as a bottle, a cup, a tube, a tray, Tupperware, etc., or a bag-like container such as a pouch, a standing pouch, a zippered storage bag, etc. In this embodiment, a bottle is preferred. In addition, it is not necessary for all parts of the bottle to contain the multilayer body of this embodiment, particularly the polyamide resin layer. For example, a polyamide resin layer may be contained in the body of the bottle, and no polyamide resin layer may be contained in the vicinity of the opening (stopper). However, it is preferable for the polyamide resin layer to extend to the vicinity of the opening of the bottle, since this further enhances the barrier performance.

[0050] The volume of the multilayer container of this embodiment is preferably 0.1 to 2.0 L, more preferably 0.2 to 1.5 L, and even more preferably 0.3 to 1.0 L, in view of the preservation of the contents. The thickness of the body of the multilayer container of this embodiment (total of the polyester resin layer, polyamide resin layer, etc.) is preferably 0.02 mm or more, more preferably 0.15 mm or more, even more preferably 0.20 mm or more, and is preferably 5.0 mm or less, more preferably 3.0 mm or less, even more preferably 2.5 mm or less. In the multilayer container of this embodiment, the thickness of the inner layer (polyester resin layer) is preferably 0.01 mm or more, more preferably 0.03 mm or more, even more preferably 0.05 mm or more, and is preferably 2.0 mm or less, more preferably 1.5 mm or less, even more preferably 1.0 mm or less. The thickness of the outer layer (polyester resin layer) is preferably 0.01 mm or more, more preferably 0.03 mm or more, and even more preferably 0.05 mm or more, and is preferably 2.0 mm or less, more preferably 1.5 mm or less, and even more preferably 1.0 mm or less. The thickness of the polyamide resin layer is preferably 0.005 mm or more, more preferably 0.01 mm or more, and even more preferably 0.02 mm or more, and is preferably 0.2 mm or less, more preferably 0.15 mm or less, and even more preferably 0.1 mm or less. When the film has two or more polyamide resin layers, it is preferable that the total thickness of the polyamide resin layers is the above-mentioned thickness. In addition, when the film has two or more polyamide resin layers and has an intermediate layer between the polyamide resin layers, the thickness of the intermediate layer is preferably 0.01 mm or more, more preferably 0.03 mm or more, even more preferably 0.05 mm or more, and is preferably 2.0 mm or less, more preferably 1.5 mm or less, even more preferably 1.0 mm or less.

[0051] The multilayer container of this embodiment has excellent oxygen barrier properties. Specifically, the oxygen barrier properties of the multilayer container of this embodiment are preferably less than 0.012 cc / (bottle·day·0.21 atm), more preferably 0.011 cc / (bottle·day·0.21 atm) or less, and even more preferably less than 0.011 cc / (bottle·day·0.21 atm). The lower limit is ideally 0 cc / (bottle·day·0.21 atm), but even if it is 0.001 cc / (bottle·day·0.21 atm) or more, the required performance is sufficiently met. The oxygen barrier property is measured according to the description in the Examples section below.

[0052] The multilayer container of this embodiment has excellent carbon dioxide gas barrier properties. Specifically, the carbon dioxide gas barrier properties of the multilayer container of this embodiment are preferably less than 1.7 cc / (bottle·day), more preferably 1.6 cc / (bottle·day) or less, more preferably 1.5 cc / (bottle·day) or less, and even more preferably less than 1.5 cc / (bottle·day). The lower limit is ideally 0 cc / (bottle·day), but even if it is 1.00 cc / (bottle·day) or more, the required performance is sufficiently met. The carbon dioxide gas barrier property is measured according to the description in the examples below.

[0053] In the multilayer container (particularly, bottle) of the present embodiment, the mass of the polyamide resin layer is preferably 1% by mass or more, more preferably 2% by mass or more, and may be 3% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less, based on the total mass of the multilayer container. By setting it to the lower limit or more, the barrier property of the multilayer container tends to be improved. Furthermore, by setting it to the upper limit or less, the transparency of the multilayer container tends to be further improved. Meanwhile, in the multilayer container of the present embodiment, the mass of the polyester resin layer is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more, based on the total mass of the multilayer container. Furthermore, in the multilayer container of the present embodiment, the mass of the polyester resin layer is preferably 99% by mass or less, more preferably 98% by mass or less, and may be 97% by mass or less, based on the total mass of the multilayer container.

[0054] The items that can be stored in the multilayer container of this embodiment are not particularly limited, and examples include food, cosmetics, pharmaceuticals, toiletries, mechanical / electrical / electronic parts, oil, resins, etc., but it is particularly suitable for use as a container for storing food. For example, processed seafood products, processed livestock products, rice, and liquid foods can be mentioned. In particular, it is suitable for preserving foods that are easily affected by oxygen. For details, refer to the descriptions in paragraphs 0032 to 0035 of JP2011-37199A, the contents of which are incorporated herein by reference. The foods to be filled are not particularly limited, but specific examples include beverages such as vegetable juices, fruit juices, teas, coffee and coffee drinks, milk and dairy drinks, mineral water, ionic drinks, alcoholic beverages, lactic acid bacteria drinks, and soy milk; gel foods such as tofu, egg tofu, jellies, puddings, mizu yokan, mousse, yogurt, and almond tofu; condiments such as sauces, soy sauce, ketchup, noodle soup, sauces, vinegar, mirin, dressings, jams, mayonnaise, miso, pickle bases, and grated spices; salami, ham, sausages, yakitori, These include processed meat products such as meatballs, hamburgers, roast pork, and beef jerky; processed seafood products such as kamaboko, boiled shellfish, boiled fish, and chikuwa; processed rice products such as porridge, cooked rice, gomoku rice, and red rice; sauces such as meat sauce, mapo sauce, pasta sauce, curry, stew, and hayashi sauce; processed dairy products such as cheese, butter, cream, and condensed milk; processed egg products such as boiled eggs and soft-boiled eggs; boiled vegetables and boiled beans; prepared dishes such as fried, steamed, stir-fried, simmered, and grilled dishes; pickles; noodles and pasta such as udon, soba, and spaghetti; and fruits pickled in syrup. Depending on the object to be preserved, the multilayer container may be sterilized or disinfected using ultraviolet rays, electron beams, gamma rays, X-rays, or the like. EXAMPLES

[0055] The present invention will be described in more detail below with reference to examples. The materials, amounts, ratios, processing contents, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

[0056] 1.Raw materials <Polyester resin> PET: isophthalic acid modified polyethylene terephthalate resin (intrinsic viscosity: 0.83 dL / g), product name: BK2180, manufactured by Mitsubishi Chemical Corporation (melting point: 248°C), content of isophthalic acid relative to total carboxylic acid components: 1.4 mol%, glass transition temperature: 79°C <Polyamide resin> MXD6: Polyamide resin synthesized from metaxylylenediamine and adipic acid, melting point: 237°C, glass transition temperature: 88°C, manufactured by Mitsubishi Gas Chemical Co., Ltd., product number: S6007 <Halide> MgCl2: Fujifilm Wako Pure Chemical Corporation, reagent LiCl: Fujifilm Wako Pure Chemical Corporation, reagent

[0057] 2. Examples 1 to 3 and Comparative Example 1 <Production of polyamide resin composition> The polyamide resin and halide shown in Table 1 (proportions of each component are in parts by mass) were dry blended, then fed into a twin-screw melt kneader (manufactured by The Japan Steel Works, Ltd., model: TEX34αIII) and melt kneaded at a cylinder temperature of 240°C to 260°C to obtain pellets of a polyamide resin composition.

[0058] <Preform manufacturing> Using an injection molding machine (Sumitomo Heavy Industries, Model SE-DU130CI) with two injection cylinders and a two-cavity multi-layer hot runner mold (Kortec), a preform partially having a three-layer structure consisting of layer (Y) / layer (X) / layer (Y) was manufactured under the conditions shown below. Specifically, first, polyester resin (PET) was injected from an injection cylinder as a material constituting layer (Y), and while maintaining the injected state of layer (Y), a polyamide resin composition constituting polyamide resin layer (X) was injected from another injection cylinder together with PET constituting layer (Y), and finally, a required amount of PET constituting layer (Y) was injected to fill the cavity, thereby obtaining a preform (25 g) partially having a three-layer structure of (Y) / (X) / (Y). The amount of injected layer (Y) and the amount of injected layer (X) when the total amount of injected resin is taken as 100 mass% are shown in Table 1. The shape of the preform was 92 mm in total length, 22 mm in outer diameter, and 3.9 mm in thickness. The preform was packaged in a moisture-proof package immediately after production and stored in this state until the start of the biaxial stretch blow process described below. <<Molding conditions>> Skin side (Y) injection cylinder temperature: 280℃ Core side (X) injection cylinder temperature: 260℃ Resin flow path temperature in mold: 290℃ Mold cooling water temperature: 15℃ Cycle time: 33 sec

[0059] <Manufacturing of multi-layer containers> The preform was biaxially stretched and blow molded using a biaxial stretch blow molding machine (Frontier, model EFB1000ET) to obtain a petaloid-shaped bottle (multilayer container). The total length of the bottle (multilayer container) was 223 mm, the outer diameter was 65 mm, and the internal volume was 500 mL (surface area: 0.04 m). 2 The average thickness of the body was 0.33 mm, and the bottom was petaloid shaped. No dimples were provided on the body. The biaxial stretch blow molding conditions were as shown below. The thicknesses of the layers of the obtained multilayer container were 150 μm, 35 μm, and 120 μm, in the order of layer (Y) / layer (X) / layer (Y). Preform heating temperature: 105℃ Primary blow pressure: 0.9MPa Secondary blow pressure: 2.5MPa First blow delay time: 0.30sec First blow time: 0.30sec Secondary blow time: 2.0sec Blow exhaust time: 0.6sec Mold temperature: 15℃

[0060] <Oxygen barrier properties> The multilayer containers produced in the examples and comparative examples were filled with 100 mL of water, and nitrogen at 1 atm was circulated inside the multilayer container at 20 mL / min under conditions of an oxygen partial pressure of 0.21 atm, an internal humidity of the multilayer container of 100% RH (relative humidity), an external humidity of 50% RH, and a temperature of 23°C. After 200 hours, the amount of oxygen contained in the nitrogen that had flowed inside the multilayer container was detected using a coulometric sensor to measure the oxygen permeability (unit: cc / (bottle day 0.21 atm)). The oxygen permeability measuring device used was a product name "OX-TRAN 2 / 61" manufactured by MOCON.

[0061] <Carbon dioxide gas barrier properties> The multi-layer containers produced in the examples and comparative examples were filled with 500 mL of 4.6 GV carbonated water, capped, and then stored for 7 days in an environment at 23°C and 50% relative humidity. The shelf life of the multi-layer container was then measured using a carbon dioxide gas transmission rate measurement device at 23°C, with a relative humidity of 100% inside the multi-layer container and a relative humidity of 50% outside the multi-layer container, with a carbon dioxide gas loss rate of 20%. The unit of carbon dioxide gas barrier property was cc / (bottle·day). The carbon dioxide gas permeability measuring device used was "PERMATRAN-C Model 10" (registered trademark) manufactured by MOCON.

[0062] [Table 1]

[0063] As is clear from the above results, the multilayer body of the present embodiment had excellent oxygen barrier properties and carbon dioxide gas barrier properties (Examples 1 to 3). In contrast, when a specific halide was not blended, the effect of improving the oxygen barrier properties and carbon dioxide gas barrier properties was not observed. [Explanation of symbols]

[0064] 1 Polyester resin layer 2 Polyamide resin layer 3 Polyester resin layer

Claims

1. A polyamide resin layer mainly composed of xylylenediamine-based polyamide resin, It contains a polyester resin layer, which is mainly composed of polyester resin. The polyamide resin layer contains at least one halide selected from the group consisting of alkali metal halides and alkaline earth metal halides. The xylylenediamine-based polyamide resin comprises a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, wherein 70 mol% or more of the diamine-derived structural unit is derived from xylylenediamine, and 70 mol% or more of the dicarboxylic acid-derived structural unit is derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. Multilayered body.

2. The multilayer according to claim 1, comprising 0.1 to 3 parts by mass of the halogenated compound per 100 parts by mass of the xylylenediamine-based polyamide resin.

3. The multilayer according to claim 1 or 2, wherein the halide comprises a chloride.

4. The multilayer according to claim 1 or 2, wherein the halide comprises magnesium halide and / or lithium halide.

5. The multilayer according to claim 1 or 2, wherein the molar ratio of metaxylylenediamine to paraxylylenediamine in the xylylenediamine is 10 to 100 / 90 to 0 when the total amount of metaxylylenediamine and paraxylylenediamine is 100 moles.

6. The multilayer according to claim 1 or 2, wherein 70 mol% or more of the constituent units derived from the dicarboxylic acid are constituent units derived from one or more of adipic acid, sebacic acid, and dodecanediic acid.

7. The multilayer according to claim 1 or 2, wherein the polyester resin comprises polyethylene terephthalate resin.

8. The halogenated compound is contained in a proportion of 0.1 to 3 parts by mass per 100 parts by mass of the xylylenediamine-based polyamide resin. The halide includes magnesium halide and / or lithium halide. The molar ratio of metaxylylenediamine to paraxylylenediamine in the aforementioned xylylenediamine is such that when the total amount of metaxylylenediamine and paraxylylenediamine is 100 moles, the ratio of metaxylylenediamine / paraxylylenediamine is 10 to 100 / 90 to 0. 70 mol% or more of the constituent units derived from the dicarboxylic acid are constituent units derived from one or more of adipic acid, sebacic acid, and dodecanediic acid. The multilayer according to claim 1, wherein the polyester resin comprises polyethylene terephthalate resin.

9. A stretched multilayer according to claim 1, 2, or 8.

10. A multilayer container comprising the multilayer body according to claim 1, 2, or 8.

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