Polyamide resin composition

Abstract

The present invention provides a polyamide resin composition which has a low hydrogen gas permeability coefficient when in the form of a molded article and has a favorable nominal tensile strain at break at a low temperature (-40°C). The polyamide resin composition contains a polyamide resin (A), a shock resistant material (B) and an inorganic compound (C), wherein: the polyamide resin (A) contains an aliphatic homopolyamide resin (A-1) and an aliphatic copolyamide resin (A-2).; and the content of the inorganic compound (C) is 1.60-3.00 parts by weight relative to 100 parts by weight of the shock resistant material (B).

Description

[Technical field]

[0001] The present invention relates to a polyamide resin composition. [Background technology]

[0002] Polyamide resins are known as resins with excellent gas barrier properties, and polyamide resin compositions with gas barrier properties are required for various applications. Patent Document 1 discloses that a polyamide resin composition consisting of polyamide 6, polyamide 6 / 66, and an impact resistant material (maleic anhydride modified EBR) has excellent gas barrier properties and excellent impact resistance at low temperatures. Patent Document 2 discloses that a polyamide resin containing an aliphatic polyamide, an aliphatic copolymer polyamide consisting of three or more monomers, an impact resistant material, and an antioxidant exhibits excellent melt viscosity, mechanical properties, and heat weldability for blow molding. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-191871 A [Patent Document 2] International Publication No. 2017 / 135215 Summary of the Invention [Problem to be solved by the invention]

[0004] However, it is sometimes difficult for the polyamide resin compositions disclosed in Patent Documents 1 and 2 to achieve both gas barrier properties against hydrogen gas and a good nominal tensile strain at break at low temperature (-40°C) in a molded article. Therefore, an object of the present invention is to provide a polyamide resin composition that has a low hydrogen gas permeability coefficient in a molded article and a good nominal tensile strain at break at low temperature (-40°C). [Means for solving the problem]

[0005] The present invention relates to the following [1] to [6]. [1] A polyamide resin composition comprising a polyamide resin (A), an impact resistant material (B) and an inorganic compound (C), The polyamide resin (A) contains an aliphatic homopolyamide resin (A-1) and an aliphatic copolymer polyamide resin (A-2), The content of the inorganic compound (C) relative to 100 parts by weight of the impact-resistant material (B) is 1.60 to 3.00 parts by weight. Polyamide resin composition. [2] The polyamide resin composition according to [1], wherein the content of the aliphatic copolyamide resin (A-2) is 5.00 to 40.00 parts by weight per 100 parts by weight of the total of the aliphatic homopolyamide resin (A-1) and the aliphatic copolyamide resin (A-2). [3] The polyamide resin composition according to [1] or [2], wherein the inorganic compound (C) is a combination of a metal halide (C-1) and an inorganic compound other than a metal halide (C-2), and the content of the metal halide (C-1) per 100 parts by weight of the inorganic compound (C) is 10 to 90 parts by weight. [4] The polyamide resin composition according to any one of [1] to [3], wherein the inorganic compound (C) contains a metal halide and talc. [5] The polyamide resin composition according to any one of [1] to [4], wherein the relative viscosity of the aliphatic homopolyamide resin (A-1) measured in 96% sulfuric acid at a concentration of 1% by weight and at 25°C in accordance with JIS K 6920 is 1.8 to 5.0. [6] The polyamide resin composition according to any one of [1] to [5], wherein the relative viscosity of the aliphatic copolyamide resin (A-2) measured in 96% sulfuric acid at a concentration of 1% by weight and at 25°C in accordance with JIS K 6920 is 1.8 to 5.0. Effect of the Invention

[0006] According to the present invention, it is possible to provide a polyamide resin composition which has a low hydrogen gas permeability coefficient in a molded article and a good nominal tensile strain at break at low temperature (-40°C). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] In this specification, the content of each component in a composition means, when a plurality of substances corresponding to each component are present in the composition, the total amount of the plurality of substances present in the composition, unless otherwise specified.

[0008] [Polyamide resin composition] The polyamide resin composition includes a polyamide resin (A), an impact resistant material (B) and an inorganic compound (C), and the polyamide resin (A) includes an aliphatic homopolyamide resin (A-1) and an aliphatic copolymer polyamide resin (A-2), and the content of the inorganic compound (C) is 1.60 to 3.00 parts by weight per 100 parts by weight of the impact resistant material (B). By setting the impact resistant material and the inorganic compound (such as talc or an inorganic heat resistance agent) to a specific weight ratio, it is possible to exhibit both a low hydrogen gas permeability coefficient and a good nominal tensile break strain at low temperature. Here, "good nominal tensile break strain at low temperature" means a good nominal tensile break strain at -40°C. In addition, since the polyamide resin composition has a low hydrogen gas permeability coefficient in a molded article, the molded article of the polyamide resin composition has excellent gas barrier properties.

[0009] <Polyamide resin (A)> The polyamide resin (A) includes an aliphatic homopolyamide resin (A-1) and an aliphatic copolymer polyamide resin (A-2). The combination of the aliphatic homopolyamide resin (A-1) and the aliphatic copolymer polyamide resin (A-2) can provide a molded product with good gas barrier properties and excellent impact resistance at low temperatures.

[0010] <Aliphatic homopolyamide resin (A-1)> Aliphatic homopolyamide resin (A-1) means a polyamide resin that has one type of monomer component that constitutes the aliphatic polyamide resin. Here, the monomer component that constitutes the aliphatic polyamide resin can be a combination of an aliphatic diamine and an aliphatic dicarboxylic acid, or a lactam or aminocarboxylic acid. In addition, when the monomer component that constitutes the aliphatic polyamide resin is a combination of an aliphatic diamine and an aliphatic dicarboxylic acid, the combination of one type of aliphatic diamine and one type of aliphatic dicarboxylic acid is regarded as one type of monomer component.

[0011] Thus, examples of the aliphatic homopolyamide resin (A-1) include an aliphatic homopolyamide resin made of a combination of one kind of aliphatic diamine and one kind of aliphatic dicarboxylic acid, an aliphatic homopolyamide resin made of lactam, and an aliphatic homopolyamide resin made of aminocarboxylic acid. Here, the number of carbon atoms of the aliphatic diamine is preferably 2 to 20, and more preferably 4 to 12. The number of carbon atoms of the aliphatic dicarboxylic acid is preferably 2 to 20, and more preferably 6 to 12. The number of carbon atoms of the lactam is preferably 6 to 12. The number of carbon atoms of the aminocarboxylic acid is preferably 6 to 12.

[0012] Examples of the aliphatic diamine include ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecanediamine, heptadecanediamine, octadecanediamine, nonadecanediamine, eicosanediamine, etc. Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedionic acid, dodecanedionic acid, tridecanedionic acid, tetradecanedionic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, eicosanedionic acid, etc.

[0013] Combinations of aliphatic diamines and aliphatic dicarboxylic acids include a combination of hexamethylenediamine and adipic acid, a combination of hexamethylenediamine and sebacic acid, and a combination of hexamethylenediamine and dodecanedioic acid, and equimolar salts of these combinations are preferably used.

[0014] Examples of lactams include ε-caprolactam, enantholactam, undecane lactam, dodecane lactam, α-pyrrolidone, α-piperidone, etc. Examples of aminocarboxylic acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. From the viewpoint of productivity, the lactam is preferably ε-caprolactam, undecane lactam, or dodecane lactam.

[0015] Specific examples of the aliphatic homopolyamide resin (A-1) include polycaprolactam (polyamide 6), polyenantholactam (polyamide 7), polyundecane lactam (polyamide 11), polylauryl lactam (polyamide 12), polyhexamethylene adipamide (polyamide 66), polytetramethylene dodecamide (polyamide 412), polypentamethylene azelamide (polyamide 59), polypentamethylene sebacamide (polyamide 510), polypentamethylene dodecamide (polyamide 512), polyhexamethylene azelamide (polyamide 69), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polynonamethylene adipamide, poly(dodecamethylene) adipamide (polyamide 96), polynonamethylene azelamide (polyamide 99), polynonamethylene sebacamide (polyamide 910), polynonamethylene dodecamide (polyamide 912), polydecamethylene adipamide (polyamide 106), polydecamethylene azelamide (polyamide 109), polydecamethylene decamamide (polyamide 1010), polydecamethylene dodecamide (polyamide 1012), polydodecamethylene adipamide (polyamide 126), polydodecamethylene azelamide (polyamide 129), polydodecamethylene sebacamide (polyamide 1210), polydodecamethylene dodecamide (polyamide 1212), polydodecamethylene oxamide (polyamide 122), and the like.

[0016] From the viewpoint of productivity, the aliphatic homopolyamide resin (A-1) is preferably one or more selected from the group consisting of polyamide 6, polyamide 66, polyamide 610, polyamide 612, polyamide 11 and polyamide 12, and particularly preferably polyamide 6 and / or polyamide 66.

[0017] The relative viscosity of the aliphatic homopolyamide resin (A-1) is not particularly limited, but the relative viscosity measured at 25°C for the aliphatic homopolyamide resin (A-1) at a concentration of 1% by weight in 96% sulfuric acid in accordance with JIS K 6920 is preferably 1.8 to 5.0, and particularly preferably 1.8 to 4.5. The relative viscosity is preferably measured as described above, but when the relative viscosity of each aliphatic homopolyamide resin (A-1) and its mixing ratio are known, the average value calculated by multiplying each relative viscosity by the mixing ratio can be used as the relative viscosity of the entire aliphatic homopolyamide resin (A-1).

[0018] The production apparatus for the aliphatic homopolyamide resin (A-1) may be a known polyamide production apparatus, such as a batch reaction vessel, a single- or multi-vessel continuous reaction apparatus, a tubular continuous reaction apparatus, a single-screw kneading extruder, a twin-screw kneading extruder, or other kneading reaction extruder. The polymerization method may be a known method such as melt polymerization, solution polymerization, or solid-phase polymerization, and may be polymerized by repeating normal pressure, reduced pressure, and increased pressure operations. These polymerization methods may be used alone or in combination as appropriate.

[0019] The aliphatic homopolyamide resin (A-1) may be one type or a combination of two or more types.

[0020] <Aliphatic copolymer polyamide resin (A-2)> The aliphatic copolyamide resin (A-2) means a polyamide resin having two or more kinds of monomer components constituting the aliphatic polyamide resin. Thus, the aliphatic copolyamide resin (A-2) includes a combination of an aliphatic diamine and an aliphatic dicarboxylic acid, and an aliphatic copolyamide resin which is a copolymer of two or more kinds of monomers selected from the group consisting of lactam and aminocarboxylic acid.

[0021] Examples of the monomer components constituting the aliphatic copolyamide resin (A-2) include the monomer components described above in relation to the aliphatic homopolyamide resin (A-1).

[0022] Specific examples of the aliphatic copolymer polyamide resin (A-2) include caprolactam / hexamethylenediaminoadipic acid copolymer (polyamide 6 / 66), caprolactam / hexamethylenediaminoazelaic acid copolymer (polyamide 6 / 69), caprolactam / hexamethylenediaminosebacic acid copolymer (polyamide 6 / 610), caprolactam / hexamethylenediaminoundecanoic acid copolymer (polyamide 6 / 611), caprolactam / hexamethylenediaminododecanoic acid copolymer (polyamide 6 / 612), caprolactam / aminoundecanoic acid copolymer (polyamide 6 / 11), caprolactam / lauryl lactam copolymer (polyamide 6 / 12), caprolactam / hexamethylenediamino adipic acid / lauryl lactam copolymer (polyamide 6 / 66 / 12), caprolactam / hexamethylenediamino adipic acid / hexamethylenediamino sebacic acid copolymer (polyamide 6 / 66 / 610), caprolactam / hexamethylenediamino adipic acid / hexamethylenediamino dodecane dicarboxylic acid copolymer (polyamide 6 / 66 / 612), hexamethylenediamino adipic acid / caprolactam copolymer (polyamide 66 / 6), etc.

[0023] From the viewpoint of productivity, the aliphatic copolyamide resin (A-2) is preferably one or more selected from the group consisting of polyamide 6 / 66, polyamide 6 / 12 and polyamide 6 / 66 / 12, and particularly preferably polyamide 6 / 66.

[0024] The relative viscosity of the aliphatic copolyamide resin (A-2) is not particularly limited, but the relative viscosity measured at 25°C for the aliphatic copolyamide resin (A-2) at a concentration of 1% by weight in 96% sulfuric acid in accordance with JIS K 6920 is preferably 1.8 to 5.0, and particularly preferably 2.0 to 4.5. The relative viscosity is preferably measured as described above, but when the relative viscosity of each aliphatic copolyamide resin (A-2) and its mixing ratio are known, the average value calculated by multiplying each relative viscosity by the mixing ratio can be used as the relative viscosity of the entire aliphatic copolyamide resin (A-2).

[0025] The production apparatus and polymerization method for the aliphatic copolyamide resin (A-2) may be the same as those described above for the aliphatic homopolyamide resin (A-1).

[0026] The aliphatic copolyamide resin (A-2) may be one type or a combination of two or more types.

[0027] <Other polyamide resins> The polyamide resin (A) may contain other polyamide resins (A-3) other than the aliphatic homopolyamide resin (A-1) and the aliphatic copolymer polyamide resin (A-2). The other polyamide resins (A-3) may be copolymer polyamide resins having functional groups such as alicyclic and aromatic groups in the main chain or side chain. Here, examples of monomer components constituting the other polyamide resins (A-3) include combinations of aliphatic or aromatic diamines and aliphatic or aromatic dicarboxylic acids, lactams, or aminocarboxylic acids. The other polyamide resins (A-3) are preferably copolymer polyamide resins containing aromatic diamines or aromatic dicarboxylic acids as monomer components. The polymerization method of the other polyamide resins (A-3) may be any known method and is not particularly limited.

[0028] Other dicarboxylic acids constituting the polyamide resin (A-3) include, for example, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, dibenzoic acid, 4,4'-oxydibenzoic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, and 4,4'-biphenyldicarboxylic acid; and alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid.

[0029] Other diamines constituting the polyamide resin (A-3) include, for example, alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine, and isophoronediamine; and aromatic diamines such as p-phenylenediamine, m-phenylenediamine, p-xylylenediamine, m-xylylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, and 4,4'-diaminodiphenylether.

[0030] Specific examples of other polyamide resins (A-3) include polycondensates of isophthalic acid / terephthalic acid / hexamethylenediamine / bis(3-methyl-4-aminocyclohexyl)methane, polycondensates of terephthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine, polycondensates of isophthalic acid / bis(3-methyl-4-aminocyclohexyl)methane / ω-laurolactam, and polycondensates of isophthalic acid / terephthalic acid / hexamethylenediamine / bis(3-methyl-4-aminocyclohexyl)methane / ω-laurolactam. Examples of the polycondensate include poly(3-methyl-4-aminocyclohexyl)methane / ω-laurolactam, ...

[0031] A specific example of the other polyamide resin (A-3) is preferably one that is composed of 40 to 95 mol% of terephthalic acid unit and 5 to 60 mol% of isophthalic acid unit, and an aliphatic diamine. A preferred combination of monomer components that constitute the other polyamide resin (A-3) is an equimolar salt of hexamethylenediamine and terephthalic acid, and an equimolar salt of hexamethylenediamine and isophthalic acid.

[0032] The other polyamide resin (A-3) is preferably a copolymer containing 60 to 99% by weight of units derived from monomer components consisting of an aliphatic diamine, isophthalic acid, and terephthalic acid, and containing 1 to 40% by weight of units of an aliphatic polyamide component.

[0033] The relative viscosity of the other polyamide resin (A-3) is not particularly limited, but it is preferably the same as that of the aliphatic homopolyamide resin (A-1) or the aliphatic copolyamide resin (A-2).

[0034] Other examples of the production apparatus and polymerization method for the polyamide resin (A-3) include the production apparatus and polymerization method described above for the aliphatic homopolyamide resin (A-1). The other polyamide resins (A-3) may be one type or a combination of two or more types.

[0035] <Preferred embodiment> From the viewpoint of efficiently enhancing the effects of the present invention, the polyamide resin (A) preferably consists of only the aliphatic homopolyamide resin (A-1) and the aliphatic copolyamide resin (A-2).

[0036] ≪Shock-resistant material (B)≫ The polyamide resin composition contains an impact resistant material (B). Examples of the impact resistant material (B) include rubber-like polymers. The impact resistant material (B) preferably has a flexural modulus of 500 MPa or less as measured in accordance with ASTM D-790.

[0037] Examples of the impact resistant material (B) include (ethylene and / or propylene) / α-olefin copolymers, (ethylene and / or propylene) / (α,β-unsaturated carboxylic acid and / or α,β-unsaturated carboxylic acid ester) copolymers, etc. The impact resistant material (B) is preferably an ethylene / α-olefin copolymer.

[0038] The (ethylene and / or propylene) / α-olefin copolymer is a polymer obtained by copolymerizing ethylene and / or propylene with an α-olefin having 3 or more carbon atoms. Examples of the α-olefins having 3 or more carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, and 12-ethyl-1-tetradecene.

[0039] The copolymer may also be one obtained by copolymerizing a polyene such as a non-conjugated diene. Examples of the non-conjugated diene include 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8-decatriene (DMDT), dicyclopentadiene, ... Examples of such norbornene include 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropylidene-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, and 2-propenyl-2,5-norbornadiene.

[0040] The (ethylene and / or propylene) / (α,β-unsaturated carboxylic acid and / or α,β-unsaturated carboxylic acid ester) copolymer is a polymer obtained by copolymerizing ethylene and / or propylene with α,β-unsaturated carboxylic acid and / or α,β-unsaturated carboxylic acid ester monomers. Examples of the α,β-unsaturated carboxylic acid monomers include acrylic acid and methacrylic acid. Examples of the α,β-unsaturated carboxylic acid ester monomers include methyl esters, ethyl esters, propyl esters, butyl esters, pentyl esters, hexyl esters, heptyl esters, octyl esters, nonyl esters, decyl esters, etc. of α,β-unsaturated carboxylic acids.

[0041] The (ethylene and / or propylene) / α-olefin copolymer and (ethylene and / or propylene) / (α,β-unsaturated carboxylic acid and / or α,β-unsaturated carboxylic acid ester) copolymer used as the impact resistant material (B) may be modified with carboxylic acid and / or its derivative. The impact resistant material (B) is preferably an (ethylene and / or propylene) / α-olefin copolymer and (ethylene and / or propylene) / (α,β-unsaturated carboxylic acid and / or α,β-unsaturated carboxylic acid ester) copolymer modified with an unsaturated carboxylic acid or its acid anhydride. When the impact resistant material (B) is the copolymer modified with an unsaturated carboxylic acid or its acid anhydride, the molecule contains a functional group having affinity for the polyamide resin (A).

[0042] Examples of the functional group having an affinity for the polyamide resin (A) include a carboxy group, an acid anhydride group, a carboxylate group, a metal salt of a carboxylate, a carboxylic acid imide group, a carboxylic acid amide group, and an epoxy group.

[0043] Examples of compounds containing functional groups having affinity for the polyamide resin (A), i.e., carboxylic acids and their derivatives, include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, mesaconic acid, citraconic acid, glutaconic acid, cis-4-cyclohexene-1,2-dicarboxylic acid, endo-bicyclo-[2.2.1]-5-heptene-2,3-dicarboxylic acid, and metal salts of these carboxylic acids, monomethyl maleate, monomethyl itaconate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and hydroxyethyl acrylate. , methyl methacrylate, 2-ethylhexyl methacrylate, hydroxyethyl methacrylate, aminoethyl methacrylate, dimethyl maleate, dimethyl itaconate, maleic anhydride, itaconic anhydride, citraconic anhydride, endo-bicyclo-[2.2.1]-5-heptene-2,3-dicarboxylic anhydride, maleimide, N-ethylmaleimide, N-butylmaleimide, N-phenylmaleimide, acrylamide, methacrylamide, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, glycidyl citraconate, etc. The compound containing a functional group having affinity for the polyamide resin (A) is preferably maleic anhydride.

[0044] The content of the acid anhydride group in the impact resistant material (B) is not particularly limited, but is preferably more than 25 μmol / g and less than 200 μmol / g, more preferably more than 25 μmol / g and less than 150 μmol / g, even more preferably more than 25 μmol / g and less than 110 μmol / g, particularly preferably more than 25 μmol / g and less than 100 μmol / g, particularly more preferably 35 μmol / g or more and less than 95 μmol, and most preferably 40 to 90 μmol / g. When the content is more than 25 μmol / g, a composition with high melt viscosity can be obtained, and the target wall thickness dimension can be obtained in blow molding. When the content is less than 200 μmol / g, the melt viscosity is not too high, and the load on the extruder can be reduced and good molding processing can be performed. The content of the acid anhydride group in the impact resistant material (B) is measured by neutralization titration with a 0.1N KOH ethanol solution using a sample solution prepared using toluene and ethanol and phenolphthalein as an indicator.

[0045] When two or more types of impact resistant materials having different acid anhydride group contents are used as the impact resistant material (B), the acid anhydride group content in the impact resistant material (B) is preferably measured by neutralization titration using a sample solution prepared using toluene and ethanol, phenolphthalein as an indicator, and a 0.1N KOH ethanol solution. However, when the acid anhydride group content of each impact resistant material and its mixing ratio are known, the acid anhydride group content of each impact resistant material may be multiplied by the mixing ratio and the total value calculated may be used as the acid anhydride content of the impact resistant material (B).

[0046] The impact-resistant material (B) preferably has an MFR of 0.1 to 10.0 g / 10 min, measured at a temperature of 230° C. and a load of 2160 g in accordance with ASTM D1238. When the MFR is within this range, the shape of the parison is prevented from becoming unstable during blow molding in extrusion molding, the thickness of the molded article tends to become more uniform, and drawdown of the parison does not become too large, tending to provide good blow moldability. The impact resistant material (B) may be one type or a combination of two or more types.

[0047] <Preferred embodiment> It is preferable that the impact resistant material (B) has a functional group having affinity for the polyamide resin (A).

[0048] ≪Inorganic compound (C)≫ The polyamide resin composition contains an inorganic compound (C). Examples of the inorganic compound (C) include a metal halide (C-1) and an inorganic compound other than a metal halide (C-2).

[0049] The metal halide (C-1) is a compound of a halogen and a metal. Examples of the halogen include fluorine, chlorine, bromine, and iodine. Examples of the metal include Group 1 elements (alkali metals), Group 2 elements (alkaline earth metals), and Group 3 to Group 12 elements (e.g., transition metals). The metal in the metal halide is preferably a Group 1 element (alkali metal) or Group 11 element (copper group).

[0050] When the metal is a Group 1 element (alkali metal), examples of the metal halide include potassium iodide, potassium bromide, potassium chloride, sodium iodide, sodium chloride, etc. When the metal is a Group 11 element (copper group), examples of the metal halide include cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, cupric iodide, etc. The metal halide (C-1) is particularly preferably cuprous iodide.

[0051] Examples of the inorganic compound (C-2) other than metal halides include metals, metal oxides, metal hydroxides, metal nitrides, metal phosphates, metal phosphites, metal carbonates, metal silicates, metal titanates, metal borates, metal sulfates, metal nitrates, etc. Specific examples of the inorganic compound (C-2) other than metal halides include talc, mica, synthetic mica, glass flakes, non-swelling mica, fullerenes, carbon nanotubes, carbon black, graphite, metal foil, ceramic beads, clay, sericite, zeolite, bentonite, aluminum hydroxide, dolomite, kaolin, silica, finely powdered silicic acid, feldspar powder, potassium titanate, shirasu balloons, calcium carbonate, magnesium carbonate, barium sulfate, calcium oxide, aluminum oxide, and titanium oxide. , magnesium oxide, aluminum silicate, silicon oxide, magnesium hydroxide, gypsum, novaculite, dawsonite, clay, glass fiber, carbon fiber, graphite fiber, metal fiber, potassium titanate whisker, aluminum borate whisker, magnesium-based whisker, silicon-based whisker, wollastonite, sepiolite, slag fiber, zonolite, elestadite, gypsum fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, and boron fiber, etc. From the viewpoint of further suppressing gas permeability, the inorganic compound (C-2) other than metal halides is preferably talc, mica, synthetic mica, glass flakes, or non-swelling mica, and particularly preferably talc.

[0052] <Characteristics of inorganic compounds (C)> When the inorganic compound (C) is a metal halide (C-1), its shape is not particularly limited. When the inorganic compound (C) is an inorganic compound (C-2) other than metal halides, the average particle size is preferably 2 to 18 μm, more preferably 5 to 16 μm, and particularly preferably 10 to 14 μm, from the viewpoint of better gas barrier properties. In this specification, the average particle size is the average particle size measured by a particle size distribution measurement method using a laser diffraction / scattering method. An example of a measurement device used in the particle size distribution measurement method is the laser diffraction particle size distribution measurement device SALD-7000 manufactured by Shimadzu Corporation. In addition, when the inorganic compound other than metal halides is a commercially available product, the average particle size of the inorganic compound is the catalog value of the commercially available product.

[0053] The inorganic compound (C) may be one or a combination of two or more of them, i.e., the inorganic compound (C) may be a combination of one or more metal halides (C-1) and one or more inorganic compounds other than metal halides (C-2).

[0054] <Preferred embodiment> From the viewpoint of imparting suitable mechanical properties to a molded article of the polyamide resin composition, the inorganic compound (C) is preferably a combination of a metal halide (C-1) and an inorganic compound other than a metal halide (C-2), more preferably a combination of a metal halide and talc, and particularly preferably a combination of a metal halide and talc.

[0055] Other Ingredients The polyamide resin composition may contain other components within the scope of the present invention, so long as the effects of the present invention are not impaired. Examples of the other components include plasticizers, heat-resistant materials, foaming agents, weathering agents, organic crystal nucleating agents, organic antioxidants, crystallization accelerators, release agents, lubricants, antistatic agents, flame retardants, flame retardant assistants, pigments, dyes, and other functionality-imparting agents. The other components are not the polyamide resin (A), the impact-resistant material (B), or the inorganic compound (C).

[0056] ≪Content≫ The content of the polyamide resin (A) relative to 100 parts by weight of the total of the polyamide resin composition is preferably 50 parts by weight or more and less than 100 parts by weight, preferably 55 to 99 parts by weight, and particularly preferably 60 to 98 parts by weight, from the viewpoint of exhibiting good gas barrier properties. The total content of the aliphatic homopolyamide resin (A-1) and the aliphatic copolymer polyamide resin (A-2) relative to 100 parts by weight of the total of the polyamide resin (A) is preferably 60 to 100 parts by weight, more preferably 90 to 100 parts by weight, and particularly preferably 95 to 100 parts by weight, from the viewpoint of exhibiting good gas barrier properties and excellent impact resistance at low temperatures.

[0057] The content of the aliphatic copolyamide resin (A-2) relative to 100 parts by weight of the total of the aliphatic homopolyamide resin (A-1) and the aliphatic copolyamide resin (A-2) is preferably 5.00 to 40.00 parts by weight, more preferably 24.00 to 24.70 parts by weight, even more preferably 24.10 parts by weight or more and less than 24.70 parts by weight, and particularly preferably 24.20 to 24.68 parts by weight. In the case of such a range, excellent impact resistance can be exhibited at low temperatures, and the processability of the molded product is improved. In addition, when the polyamide resin (A) is composed only of the aliphatic homopolyamide resin (A-1) and the aliphatic copolyamide resin (A-2), the above content is the content of the aliphatic copolyamide resin (A-2) relative to 100 parts by weight of the total of the polyamide resin (A).

[0058] The content of the inorganic compound (C) relative to 100 parts by weight of the impact resistant material (B) is 1.60 to 3.00 parts by weight. In such a range, the impact resistant material (B) exerts an impact resistance imparting effect, and even if the impact resistant material is imparted, the inherent properties of the polyamide resin, such as strength and heat resistance, can be maintained, and the gas barrier property imparting effect of the inorganic compound (C) can be efficiently enhanced. In addition, when the content of the inorganic compound (C) relative to 100 parts by weight of the impact resistant material (B) is less than 1.60 parts by weight, the amount of the inorganic compound (C) relative to the impact resistant material (B) becomes too small, so that the gas barrier property is inferior. The content of the inorganic compound (C) relative to 100 parts by weight of the impact resistant material (B) is preferably 1.65 to 3.00 parts by weight, and particularly preferably 1.70 to 3.00 parts by weight.

[0059] The contents of the impact-resistant material (B) and the inorganic compound (C) in the polyamide resin composition are not particularly limited, so long as they are within the range of the content of the inorganic compound (C) relative to 100 parts by weight of the impact-resistant material (B) described above.

[0060] The content of the impact resistant material (B) relative to 100 parts by weight of the polyamide resin composition is preferably 5 to 30 parts by weight, more preferably 5 to 25 parts by weight, and particularly preferably 7 to 20 parts by weight, from the viewpoints of gas barrier properties and good nominal tensile break strain at low temperature. The polyamide resin composition is placed in an autoclave and treated with hydrochloric acid at 150°C for 16 hours, whereby the polyamide component can be hydrolyzed, and the undecomposed component can be taken out as the impact resistant material (B) component.

[0061] The content of the inorganic compound (C) relative to 100 parts by weight of the total of the polyamide resin composition is preferably 0.01 to 0.5 parts by weight, more preferably 0.01 to 0.4 parts by weight, and particularly preferably 0.02 to 0.3 parts by weight, from the viewpoint of better gas barrier properties and nominal tensile break strain at low temperature. In addition, when the inorganic compound (C) is a combination of a metal halide (C-1) and an inorganic compound (C-2) other than a metal halide, the content of the metal halide (C-1) relative to 100 parts by weight of the total of the inorganic compound (C) is more preferably 10 to 90 parts by weight, and particularly preferably 30 to 85 parts by weight, from the viewpoint of gas barrier properties.

[0062] [Method of producing polyamide resin composition] The method for producing the polyamide resin composition is not particularly limited, and for example, the following method can be applied. Polyamide resin (A), impact resistant material (B), inorganic compound (C) and other components can be mixed using a commonly known melt kneader such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, and a mixing roll. Specific mixing methods that are not limited include a method of blending all raw materials using a twin-screw extruder, melt kneading the raw materials after blending them, a method of blending some raw materials, melt kneading them, and further blending the remaining raw materials and melt kneading them, or a method of blending some raw materials, and then mixing the remaining raw materials using a side feeder during melt kneading.

[0063] [Uses of polyamide resin composition] The polyamide resin composition is not particularly limited and can be used for the production of molded articles using known methods. Specifically, the polyamide resin composition can be used for the production of injection molded articles by injection molding, the production of blow molded articles by blow molding, or the production of extrusion molded articles by extrusion molding. Among them, the polyamide resin composition of the present invention is suitable for the production of blow molded articles by blow molding and the production of extrusion molded articles by extrusion molding. A method for producing a blow molded article from a polyamide resin by blow molding generally includes forming a parison using a normal blow molding machine and then performing blow molding. The resin temperature during the formation of the parison is preferably in the range of 10°C to 70°C higher than the melting point of the polyamide resin composition.

[0064] The method of producing an extrusion molded article from a polyamide resin by extrusion molding generally involves co-extrusion with a polyolefin such as polyethylene or other thermoplastic resin, followed by blow molding to obtain a multilayer structure. Here, it is also possible to provide an adhesive layer between the polyamide resin composition layer and the other thermoplastic resin layer such as polyolefin. When the molded article is a multilayer structure, the polyamide resin composition of the present invention can be used for either the outer layer or the inner layer.

[0065] Suitable applications of injection molded products produced by injection molding, blow molded products produced by blow molding, or extrusion molded products produced by extrusion molding include, but are not limited to, automobile parts such as spoilers, air intake ducts, intake manifolds, resonators, fuel tanks, gas tanks, hydraulic oil tanks, fuel filler tubes, fuel delivery pipes, and various other hoses, tubes, and tanks; machine parts such as power tool housings and pipes; electric and electronic parts such as tanks, tubes, hoses, and films; household and office supplies; building material-related parts; and furniture parts. Polyamide resin compositions have excellent gas barrier properties and are therefore suitable for use in molded articles that come into contact with gas, such as tanks, tubes, hoses, films, and the like that come into contact with gas. The type of the gas is not particularly limited, but examples thereof include hydrogen, nitrogen, oxygen, helium, methane, butane, and propane. Gases with low polarity are preferred, with hydrogen and nitrogen being particularly preferred. EXAMPLES

[0066] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. The components used in the examples and comparative examples and the methods for evaluating the physical properties of the molded products are shown below.

[0067] [Hydrogen gas permeability coefficient] Various test pieces were prepared by injection molding and used to obtain data on mechanical properties. According to JIS K7126-1, hydrogen gas permeation tests were performed using 2 mm thick test pieces at 15℃ or 55℃, 1 atm, and 0% RH by gas chromatography. The measuring devices used were GTR-30XAD (GTR Tech Co., Ltd.) and G6800T·F (Yanaco Technical Science Co., Ltd.). The test pieces were manufactured under the following melt-kneading and injection molding conditions.

[0068] [Nominal tensile strain at break] The tests were conducted in accordance with ISO 527-1,2 at room temperature (23°C) and -40°C using ISO Type-A test pieces with a thickness of 4.0 mm. The nominal tensile strain at break at low temperature (-40°C) was evaluated according to the following: ○: After yielding, it was stretched sufficiently and broke ×: Break occurs immediately after yielding

[0069] [Ingredients used] 1. Polyamide resin (A) (1) Aliphatic homopolyamide resin (A-1) PA6: Polyamide 6 (Ube Industries, Ltd.: relative viscosity = 2.98) (2) Aliphatic copolymer polyamide resin (A-2) PA6 / 66: Polyamide 6 / 66 (Ube Industries, Ltd.: relative viscosity = 4.05) The relative viscosity of the aliphatic homopolyamide resin (A-1) and the aliphatic copolyamide resin (A-2) used in the examples was measured in 96% sulfuric acid at a concentration of 1% by weight at 25°C in accordance with JIS K 6920.

[0070] 2. Impact resistant material (B) (1) Tafmer MH5020: Maleic anhydride modified ethylene-butylene copolymer (Tafmer (registered trademark) MH5020, manufactured by Mitsui Chemicals, Inc.: density ρ = 0.86)

[0071] 3.Inorganic compounds (C) (1) Metal halide (C-1) CuI, KI mixture (weight ratio 1:6) CuI: Cuprous iodide (Ise Chemical Industry Co., Ltd.) KI: Powdered potassium iodide (Mitsui Fine Co., Ltd.) (2) Inorganic compounds other than metal halides (C-2) Talc: KHP-400 (Hayashi Kasei Co., Ltd., average particle size 11 μm (catalog value))

[0072] [Examples 1 to 3, Comparative Examples 1 to 2] The components shown in Table 1 were melt-kneaded under the following melt-kneading conditions to prepare the desired polyamide resin composition pellets. The pellets thus obtained were then used to prepare various test pieces, and various physical properties were evaluated.

[0073] <Melting and kneading conditions> Uses TEX-44 twin screw extruder Cylinder diameter: 44mm L / D:35 Screw rotation speed: 120 rpm

[0074] <Injection molding conditions> Cylinder temperature: 270℃ Mold temperature: 80℃ Average injection speed in the mold: 50mm / sec Cooling time: 5 seconds

[0075] The results obtained are shown in Table 1.

[0076] [Table 1]

[0077] As is clear from the results in Table 1, the polyamide resin compositions of the examples give molded articles with low hydrogen gas permeability and excellent nominal tensile strain at break. The resin composition of Comparative Example 1 had a high hydrogen gas permeability coefficient because the content of the inorganic compound (C) per 100 parts by weight of the impact-resistant material (B) was less than 1.60 parts by weight. The resin composition of Comparative Example 2 did not contain the impact-resistant material (B), and therefore was inferior in nominal tensile strain at break at low temperatures.

Claims

1. A polyamide resin composition comprising a polyamide resin (A), an impact resistant material (B) and an inorganic compound (C), The polyamide resin (A) contains an aliphatic homopolyamide resin (A-1) and an aliphatic copolyamide resin (A-2), The content of the inorganic compound (C) relative to 100 parts by weight of the impact resistant material (B) is 1.60 to 3.00 parts by weight; Polyamide resin composition.

2. The polyamide resin composition according to claim 1, wherein the content of the aliphatic copolyamide resin (A-2) is 5.00 to 40.00 parts by weight based on 100 parts by weight of the total of the aliphatic homopolyamide resin (A-1) and the aliphatic copolyamide resin (A-2).

3. 3. The polyamide resin composition according to claim 1, wherein the inorganic compound (C) is a combination of a metal halide (C-1) and an inorganic compound (C-2) other than a metal halide, and the content of the metal halide (C-1) per 100 parts by weight of the inorganic compound (C) is 10 to 90 parts by weight.

4. The polyamide resin composition according to any one of claims 1 to 3, wherein the inorganic compound (C) comprises a metal halide and talc.

5. The polyamide resin composition according to any one of claims 1 to 4, wherein the aliphatic homopolyamide resin (A-1) has a relative viscosity of 1.8 to 5.0 as measured in 96% sulfuric acid at a concentration of 1% by weight and at 25°C in accordance with JIS K 6920.

6. The polyamide resin composition according to any one of claims 1 to 5, wherein the aliphatic copolyamide resin (A-2) has a relative viscosity of 1.8 to 5.0, as measured in 96% sulfuric acid at a concentration of 1% by weight and at 25°C in accordance with JIS K 6920.

7. A polyamide resin composition described in any one of claims 1 to 6, wherein the inorganic compound (C) is a combination of a metal halide (C-1) and an inorganic compound (C-2) other than a metal halide, and the metal halide (C-1) is a combination of an alkali metal halide and a copper halide.

8. The inorganic compound (C) is a combination of a metal halide (C-1) and an inorganic compound other than a metal halide (C-2), and the inorganic compound other than a metal halide (C-2) is selected from the group consisting of talc, mica, synthetic mica, glass flakes, non-swelling mica, fullerene, carbon nanotubes, carbon black, graphite, metal foil, ceramic beads, clay, sericite, zeolite, bentonite, aluminum hydroxide, dolomite, kaolin, silica, finely powdered silicic acid, feldspar powder, potassium titanate, shirasu balloons, calcium carbonate, magnesium carbonate, barium sulfate, calcium oxide, aluminum oxide, acid The polyamide resin composition according to any one of claims 1 to 7, wherein the fiber is at least one selected from the group consisting of titanium dioxide, magnesium oxide, aluminum silicate, silicon oxide, magnesium hydroxide, gypsum, novaculite, dawsonite, white clay, glass fiber, carbon fiber, graphite fiber, metal fiber, potassium titanate whisker, aluminum borate whisker, magnesium whisker, silicon whisker, wollastonite, sepiolite, slag fiber, zonolite, elestadite, gypsum fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, and boron fiber.

9. A polyamide resin composition described in any one of claims 1 to 8, wherein the inorganic compound (C) is a combination of a metal halide (C-1) and an inorganic compound other than a metal halide (C-2), and the content of the metal halide (C-1) per total 100 parts by weight of the polyamide resin composition is 0.25 to 0.30 parts by weight.

10. A polyamide resin composition described in any one of claims 1 to 9, wherein the inorganic compound (C) is a combination of a metal halide (C-1) and an inorganic compound other than a metal halide (C-2), and the content of the inorganic compound other than a metal halide (C-2) is 0.05 to 0.10 parts by weight per 100 parts by weight of the polyamide resin composition in total.

11. A polyamide resin composition described in any one of claims 1 to 10, wherein the inorganic compound (C) is a combination of a metal halide (C-1) and an inorganic compound other than a metal halide (C-2), and the average particle diameter of the inorganic compound other than a metal halide (C-2) is 2 to 18 μm.

12. A polyamide resin composition described in any one of claims 1 to 11, wherein the inorganic compound (C) is a combination of a metal halide (C-1) and an inorganic compound other than a metal halide (C-2), the inorganic compound other than a metal halide (C-2) is talc, and the average particle diameter of the talc is 10 to 14 μm.

13. A molded article comprising the polyamide resin composition according to any one of claims 1 to 12.

14. The molded article of claim 13, which is in contact with a gas.

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