JP2017226817A - Polyamide resin composition for molding in contact with high-pressure hydrogen, and molding prepared therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide resin composition that makes it possible to obtain a molding in which: a defect point is prevented from occurring when the charging and discharge of high-pressure hydrogen are repeated; and the releasability is excellent.SOLUTION: The present invention provides a polyamide resin composition for a molding in contact with high-pressure hydrogen. The polyamide resin composition contains, based on polyamide 6 resin (A) 100 pts.wt., amide wax (B) 0.01-10 pts.wt.SELECTED DRAWING: None

Description

  The present invention relates to a polyamide resin composition for a molded article that comes into contact with high-pressure hydrogen, comprising a specific amount of an amide wax mixed with polyamide 6 resin, and a molded article obtained by molding the polyamide resin composition.

  In recent years, fuel cells that generate electricity by electrochemically reacting hydrogen and oxygen in the air have been installed in automobiles in order to meet the demand for petroleum fuel depletion and reduction of harmful gas emissions. 2. Description of the Related Art Fuel cell electric vehicles that use the supplied electricity as a driving force by supplying motors have attracted attention. As a high-pressure hydrogen tank for use in automobiles, a resin tank in which the outside of a resin liner is reinforced with carbon fiber reinforced resin has been studied. However, since hydrogen has a small molecular size, it is easier to permeate through the resin than natural gas with a relatively large molecular size, and high-pressure hydrogen accumulates in the resin compared to atmospheric hydrogen. Because of the increase in the number of conventional resin tanks, there has been a problem that deformation and destruction of the tank occur when high-pressure hydrogen filling and releasing are repeated. In addition, when molding a resin liner, there is a problem that the releasability is insufficient.

  As a hydrogen tank liner material having excellent gas barrier properties and excellent impact resistance even at low temperatures, for example, a hydrogen tank liner material comprising a polyamide resin composition including polyamide 6, copolymerized polyamide, and an impact resistant material has been studied. (For example, refer to Patent Document 1).

  Further, as a gas storage tank liner having excellent gas barrier properties, for example, a gas storage tank liner containing a polymer composition containing polyamide, a nucleating agent, and an impact resistance improving agent has been studied (for example, Patent Documents). 2).

JP 2009-191871 A Special table 2014-501818 gazette

  One of the methods for producing a molded product that comes into contact with high-pressure hydrogen is injection molding. For example, when injection molding a resin gas storage tank liner, a large molded product will be molded. If the molded product has poor appearance due to insufficient releasability, the molded product cannot be obtained. There is. For this reason, high mold releasability is required in order to injection mold a large molded product.

  However, the hydrogen tank liner described in Patent Document 1 is likely to cause permeation of hydrogen gas and dissolution of hydrogen into the resin, and defects are generated in the hydrogen tank liner when repeated filling and releasing of high-pressure hydrogen. There was a problem. Moreover, the releasability of the polyamide resin was low, and there was a problem in the releasability.

  The gas storage tank liner described in Patent Document 2 is excellent in helium gas permeation resistance, but easily permeates hydrogen gas or dissolves hydrogen in a resin. When the process was repeated, there was a problem that defects occurred in the hydrogen tank liner. Moreover, the releasability of the polyamide resin was low, and there was a problem in the releasability.

  The present invention provides a polyamide resin composition in which the occurrence of defects is suppressed even after repeated filling and releasing of high-pressure hydrogen, and a molded article having excellent releasability can be obtained in view of the above-described problems of the prior art. The task is to do.

  In order to achieve the above object, the present invention has the following configuration.

  A polyamide resin composition for molded articles that comes into contact with high-pressure hydrogen, comprising 0.01 to 10 parts by weight of an amide wax (B) per 100 parts by weight of a polyamide 6 resin (A).

  This invention includes the molded article which contacts the high pressure hydrogen which consists of said polyamide resin composition.

  The present invention includes a high-pressure hydrogen tank liner comprising the above polyamide resin composition.

  The present invention includes a high-pressure hydrogen tank in which a carbon fiber reinforced resin reinforcing layer is laminated on the surface layer of a tank liner made of the polyamide resin composition.

  The polyamide resin composition for molded articles that comes into contact with high-pressure hydrogen of the present invention has a high crystallization temperature, and crystallization from a molten state proceeds quickly, so that the crystallization speed increases, and filling and releasing of high-pressure hydrogen are repeated. In addition, generation of defects can be suppressed, and a molded product excellent in releasability can be provided. The molded article of the present invention is usefully developed as a molded article that is used in applications that come into contact with high-pressure hydrogen, taking advantage of its excellent releasability, since defects do not easily occur even after repeated filling and releasing of high-pressure hydrogen. It becomes possible to do.

  Hereinafter, the present invention will be described in more detail.

  The polyamide resin composition for molded articles that is exposed to high-pressure hydrogen of the present invention (hereinafter sometimes referred to as “polyamide resin composition”) is an amide wax (B) with respect to 100 parts by weight of the polyamide 6 resin (A). ) 0.01 to 10 parts by weight. By blending a specific amount of the amide wax (B) with the polyamide 6 resin (A), which has an excellent balance of moldability, gas barrier properties, rigidity and toughness, the crystallization temperature is high and the crystallization from the molten state proceeds quickly. Therefore, since the crystallization speed is increased and dense and uniform crystals are formed, the permeation of hydrogen gas and the dissolution of hydrogen into the resin can be suppressed, so the filling and releasing of high-pressure hydrogen are repeated. However, it is difficult for defect points to occur. Moreover, the mold release property at the time of shaping | molding improves, and the molded article excellent in the mold release property can be obtained. On the other hand, when a combination of a polyamide 6 resin (A) and a mold release agent, organic nucleating agent, or inorganic nucleating agent other than the amide wax (B) is repeated filling and releasing of high-pressure hydrogen, there is a defect in the molded product. In addition, the releasability at the time of molding does not improve, and the toughness of the molded product decreases.

  The polyamide 6 resin (A) used in the present invention is a polyamide resin mainly containing 6-aminocaproic acid and / or ε-caprolactam. Other monomers may be copolymerized as long as the object of the present invention is not impaired. Here, “to be used as a main raw material” means that a unit derived from 6-aminocaproic acid or a unit derived from ε-caprolactam is included in a total of 50 mol% or more in a total of 100 mol% of monomer units constituting the polyamide resin. Means. It is more preferable that the unit derived from 6-aminocaproic acid or the unit derived from ε-caprolactam is contained by 70 mol% or more, and more preferably 90 mol% or more.

  Examples of other monomers to be copolymerized include amino acids such as 11-aminoundecanoic acid, 12-aminododecanoic acid, and paraaminomethylbenzoic acid, lactams such as ω-laurolactam; tetramethylenediamine, pentamethylenediamine, Aliphatic diamines such as hexamethylenediamine, 2-methylpentamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine; Aromatic diamines such as meta-xylenediamine and paraxylylenediamine; 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5 -Trimethylcyclohexane, bis (4-a Alicyclic diamines such as nocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine; adipic acid Aliphatic dicarboxylic acids such as suberic acid, azelaic acid, sebacic acid, dodecanedioic acid; terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid , Aromatic dicarboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid; 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, etc. The alicyclic dicarbo Examples include acid. Two or more of these may be copolymerized.

  The degree of polymerization of the polyamide 6 resin (A) is not particularly limited, but the relative viscosity measured at 25 ° C. in a 98% concentrated sulfuric acid solution having a resin concentration of 0.01 g / ml is in the range of 1.5 to 7.0. It is preferable that When the relative viscosity is 1.5 or more, the melt viscosity of the polyamide resin composition at the time of molding becomes moderately high, the air entrainment at the time of molding can be suppressed, and the moldability can be further improved. The relative viscosity is more preferably 1.8 or more. On the other hand, if the relative viscosity is 7.0 or less, the melt viscosity at the time of molding of the polyamide resin composition becomes moderately low, and the moldability can be further improved.

There is no particular limitation on the amino end groups of the polyamide 6 resin (A), the it is preferably in the range of ^{1.0 × 10 -5 ~10.0 × 10 -5} mol / g. When the amino terminal group amount is in the range of 1.0 × 10 ^{−5 to} 10.0 × 10 ⁻⁵ mol / g, a sufficient degree of polymerization can be obtained, and the mechanical strength of the molded product can be improved. Here, the amount of amino terminal groups of the polyamide 6 resin (A) was determined by dissolving the polyamide 6 resin (A) in a phenol / ethanol mixed solvent (83.5: 16.5 (volume ratio)) and adding 0.02N hydrochloric acid. It can be determined by titrating with an aqueous solution.

  The amide wax (B) used in the present invention is an amide compound obtained by reacting a monocarboxylic acid and a diamine, an amide compound obtained by reacting a monoamine and a polybasic acid, or a monocarboxylic acid, a polybasic acid and a diamine. Examples thereof include amide compounds obtained by reaction. These can be obtained by dehydration reaction of the corresponding amine and carboxylic acid.

  The monoamine is preferably a monoamine having 5 or more carbon atoms, and specific examples thereof include pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dodecylamine, stearylamine, cyclohexylamine, and benzylamine. These may be used in combination of two or more. Of these, higher aliphatic monoamines having 10 to 20 carbon atoms are particularly preferred. If the carbon number is greater than 20, the compatibility with the polyamide 6 resin (A) is lowered and there is a risk of precipitation.

  The monocarboxylic acid is preferably an aliphatic monocarboxylic acid or hydroxycarboxylic acid having 5 or more carbon atoms. Specific examples thereof include valeric acid, caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, olein. Acid, linoleic acid, behenic acid, montanic acid, 12-hydroxystearic acid, benzoic acid and the like may be mentioned, and these may be used in combination of two or more. Of these, higher aliphatic monocarboxylic acids having 10 to 30 carbon atoms are particularly preferred. When the number of carbon atoms is greater than 30, the compatibility with the polyamide 6 resin (A) is lowered and there is a risk of precipitation.

  Specific examples of the diamine include ethylenediamine, 1,3-diaminopropane, 1,4-diaminopropane, tetramethylenediamine, hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, metaxylylenediamine, Paraxylylenediamine, tolylenediamine, phenylenediamine, isophoronediamine and the like may be mentioned, and two or more of these may be used in combination. Of these, ethylenediamine is particularly preferred.

  The polybasic acid is a dicarboxylic acid or higher carboxylic acid, and specific examples thereof include aliphatic dicarboxylic acids such as malonic acid, succinic acid, adipic acid, sebacic acid, pimelic acid, azelaic acid, phthalic acid, terephthalic acid, and the like. Examples thereof include aromatic dicarboxylic acids such as acid and isophthalic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and cyclohexylsuccinic acid. These may be used in combination of two or more.

  Of these, an amide compound obtained by reacting a higher aliphatic monocarboxylic acid, a polybasic acid and a diamine is particularly suitable. For example, an amide compound obtained by reacting stearic acid, sebacic acid and ethylenediamine is preferred. The mixing ratio of each component is preferably in the range of 0.18 to 1.0 mol of polybasic acid and 1.0 to 2.2 mol of diamine with respect to 2 mol of higher aliphatic monocarboxylic acid. The range of 0.5 mol to 1.0 mol of polybasic acid and 1.5 mol to 2.0 mol of diamine is more suitable for 2 mol of higher aliphatic monocarboxylic acid.

Although there is no restriction | limiting in particular in melting | fusing point of amide type wax (B), It is preferable that melting | fusing point by DSC measurement is more than melting | fusing point of polyamide 6 resin (A). When the melting point of the amide wax (B) is equal to or higher than the melting point of the polyamide 6 resin (A), the releasability during molding is further improved.

  Here, the melting point by DSC measurement of the polyamide 6 resin (A) and the amide wax (B) in the present invention can be determined by the following method. First, using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer), two-point calibration (indium, lead) and baseline correction are performed. The sample amount was set to 8 to 10 mg, held for 1 minute at a temperature 15 ° C. higher than the temperature showing the maximum value of the melting curve obtained by heating at a heating rate of 20 ° C./min, and then the temperature was lowered to 20 ° C./min. Cool to 30 ° C at speed. Further, after being held at a temperature of 30 ° C. for 1 minute, the second temperature raising step is performed at a rate of 20 ° C./min, similarly to the first temperature raising step. The melting endothermic peak temperature observed in the second temperature raising step is defined as the melting point.

  The compounding quantity of the amide type wax (B) in the polyamide resin composition of this invention is 0.01-10 weight part with respect to 100 weight part of polyamide 6 resin (A). When the blending amount of the amide wax (B) is less than 0.01 parts by weight, the effect of improving the releasability is not sufficient, and defects are likely to occur due to repeated filling and releasing of high-pressure hydrogen. Become. The amount of the amide wax (B) is preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more. On the other hand, when the compounding amount of the amide wax (B) exceeds 10 parts by weight, the toughness is lowered, and defective points are easily generated by repeating filling and releasing of high-pressure hydrogen. The amount of the amide wax (B) is preferably 7 parts by weight or less, and more preferably 5 parts by weight or less.

  The polyamide resin composition is preferably further blended with an impact resistant material (C). By blending the impact resistant material (C), the impact resistance of the molded product can be improved. In addition, a molded article used for an application that contacts high-pressure hydrogen repeatedly undergoes a temperature change (heat cycle) from −40 ° C. or lower to 90 ° C. or higher due to filling and releasing of high-pressure hydrogen. In the case of a composite product having a part, cracks are likely to occur at the joint between the resin part and the metal part. By mix | blending an impact-resistant material (C), the crack in the junction part of the resin part and metal part which arises by repetition of such a heat cycle can be suppressed, and heat cycle resistance can be improved.

  Examples of the impact resistant material (C) include olefin resin, acrylic rubber, silicone rubber, fluorine rubber, styrene rubber, nitrile rubber, vinyl rubber, urethane rubber, polyamide elastomer, polyester elastomer, ionomer. Etc. Two or more of these may be blended.

  Among these, an olefin resin is preferably used because of excellent compatibility with the polyamide 6 resin (A) and the amide wax (B) and a high effect of improving heat cycle resistance. The olefin resin is a thermoplastic resin obtained by polymerizing olefin monomers such as ethylene, propylene, butene, isoprene, and pentene. The copolymer of 2 or more types of olefin monomers may be sufficient, and the copolymer of these olefin monomers and another monomer may be sufficient. Specific examples of the olefin resin include polymers such as polyethylene, polypropylene, polystyrene, poly 1-butene, poly 1-pentene, polymethyl pentene or copolymers thereof; ethylene / α-olefin copolymer, ethylene / α, β-unsaturated carboxylic acid ester copolymer, α-olefin / α, β-unsaturated carboxylic acid ester copolymer, [copolymer of (ethylene and / or propylene) and vinyl alcohol ester] Polyolefin obtained by partially hydrolyzing, a copolymer of (ethylene and / or propylene) and (unsaturated carboxylic acid and / or unsaturated carboxylic ester), [(ethylene and / or propylene) and (unsaturated) Copolymer of saturated carboxylic acid and / or unsaturated carboxylic acid ester) Polyolefins obtained by at least a portion of the cyclohexyl group and a metal chloride, such as a block copolymer or its hydrogenation product of a conjugated diene and a vinyl aromatic hydrocarbons. Among these, an ethylene / α-olefin copolymer and an ethylene / α, β-unsaturated carboxylic acid ester copolymer are more preferable, and an ethylene / α-olefin copolymer is more preferable.

  The polyolefin resin may be modified with an unsaturated carboxylic acid and / or a derivative thereof. Here, the derivative of unsaturated carboxylic acid is a compound obtained by substituting the hydroxy group portion of the carboxyl group of unsaturated carboxylic acid with another substituent, and includes a metal salt, an acid halide, an ester, an acid of unsaturated carboxylic acid. Anhydrides, amides and imides. By using such a modified polyolefin resin, the compatibility with the polyamide 6 resin (A) and the amide wax (B) can be further improved, and the heat cycle resistance can be further improved. Examples of the unsaturated carboxylic acid or derivative thereof include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylmaleic acid, methyl fumaric acid, mesaconic acid, citraconic acid, glutaconic acid and carboxylic acids thereof. Metal salts of: methyl hydrogen maleate, methyl itaconate hydrogen, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 2-ethylhexyl methacrylate, meta Unsaturated carboxylic acid esters such as hydroxyethyl acrylate, aminoethyl methacrylate, dimethyl maleate, dimethyl itaconate; maleic anhydride, itaconic anhydride, citraconic anhydride, endobicyclo- (2,2,1) -5 -Heptene- , 3-dicarboxylic acid, acid anhydrides such as endobicyclo- (2,2,1) -5-heptene-2,3-dicarboxylic acid anhydride; maleimide, N-ethylmaleimide, N-butylmaleimide, N-phenyl Examples include maleimide, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, glycidyl citraconic acid, and 5-norbornene-2,3-dicarboxylic acid. Among these, unsaturated dicarboxylic acid and its acid anhydride are preferable, and maleic acid or maleic anhydride is particularly preferable.

  As a method for introducing these unsaturated carboxylic acids or derivatives thereof into the polyolefin-based resin, for example, a method of copolymerizing an olefin monomer and an unsaturated carboxylic acid and / or a derivative thereof, using a radical initiator, Examples thereof include a method of grafting an unsaturated carboxylic acid and / or a derivative thereof into an unmodified polyolefin resin.

  As the ethylene / α-olefin copolymer, a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms is preferable. Specific examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 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, 12-ethyl-1-tetradecene and the like.Two or more of these may be used. Among these α-olefins, α-olefins having 3 to 12 carbon atoms are preferable from the viewpoint of improving mechanical strength. Further, non-conjugated dienes such as 1,4-hexadiene, dicyclopentadiene, 2,5-norbornadiene, 5-ethylidenenorbornene, 5-ethyl-2,5-norbornadiene, 5- (1′-propenyl) -2-norbornene At least one of these may be copolymerized. A copolymer of ethylene modified with an unsaturated carboxylic acid and / or a derivative thereof and an α-olefin having 3 to 12 carbon atoms further enhances compatibility with the polyamide 6 resin (A) and the amide wax (B). It is more preferable because the heat cycle resistance can be further improved. Moreover, even if filling and releasing pressure are repeated with higher-pressure hydrogen, generation of defect points can be suppressed. The α-olefin content in the ethylene / α-olefin copolymer is preferably 1 to 30 mol%, more preferably 2 to 25 mol%, and still more preferably 3 to 20 mol%.

  The structure of the impact-resistant material (C) is not particularly limited. For example, a multilayer structure called a so-called core-shell type consisting of at least one layer made of rubber and one or more layers made of a polymer different from the rubber. It may be. The number of layers constituting the multilayer structure may be two or more, and may be three or more or four or more, but preferably has one or more rubber layers (core layers) inside. . The type of rubber constituting the rubber layer of the multilayer structure is not particularly limited. For example, acrylic component, silicone component, styrene component, nitrile component, conjugated diene component, urethane component, ethylene component, propylene component, isobutene Examples thereof include rubber obtained by polymerizing components. The kind of the different polymer constituting the layer other than the rubber layer of the multilayer structure is not particularly limited as long as it is a polymer having thermoplasticity, but there is a polymer having a glass transition temperature higher than that of the rubber layer. preferable. As the polymer having thermoplasticity, for example, an unsaturated carboxylic acid alkyl ester unit, an unsaturated carboxylic acid unit, an unsaturated glycidyl group-containing unit, an unsaturated dicarboxylic acid anhydride unit, an aliphatic vinyl unit, an aromatic vinyl unit, Examples thereof include polymers containing vinyl cyanide units, maleimide units, unsaturated dicarboxylic acid units and other vinyl units.

  The blending amount of the impact resistant material (C) in the polyamide resin composition is preferably 1 to 50 parts by weight with respect to 100 parts by weight of the polyamide 6 resin (A). Heat cycle resistance can be improved more by making the compounding quantity of an impact-resistant material (C) into 1 weight part or more. The amount of the impact resistant material (C) is more preferably 5 parts by weight or more, and still more preferably 10 parts by weight or more. On the other hand, by setting the blending amount of the impact resistant material (C) to 50 parts by weight or less, generation of defect points can be suppressed even when filling and releasing with high-pressure hydrogen are repeated. The amount of the impact resistant material (C) is more preferably 45 parts by weight or less, further preferably 40 parts by weight or less, and further preferably 35 parts by weight or less.

  In the polyamide resin composition, other components other than the components (A), (B), and (C) may be blended as necessary within a range that does not impair the characteristics. Examples of other components include a filler, thermoplastic resins other than the components (A) to (C), and various additives.

  For example, the strength, dimensional stability, and the like of the obtained molded product can be improved by blending the polyamide resin composition with other fillers as other components. The shape of the filler may be fibrous or non-fibrous, or a combination of fibrous filler and non-fibrous filler may be used. Examples of the fibrous filler include glass fiber, glass milled fiber, carbon fiber, potassium titanate whisker, zinc oxide whisker, aluminum borate whisker, aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, and stone powder. Examples thereof include fibers and metal fibers. Non-fibrous fillers include, for example, silicates such as wollastonite, zeolite, sericite, kaolin, mica, clay, pyrophyllite, bentonite, asbestos, talc, alumina silicate; alumina, silicon oxide, magnesium oxide, oxidation Metal oxides such as zirconium, titanium oxide and iron oxide; metal carbonates such as calcium carbonate, magnesium carbonate and dolomite; metal sulfates such as calcium sulfate and barium sulfate; magnesium hydroxide, calcium hydroxide and aluminum hydroxide Metal hydroxide; glass beads, ceramic beads, boron nitride, silicon carbide and the like. These may be hollow. In addition, it is preferable to use these fibrous and / or non-fibrous fillers after pretreatment with a coupling agent in terms of obtaining superior mechanical properties. Examples of the coupling agent include isocyanate compounds, organic silane compounds, organic titanate compounds, organic borane compounds, and epoxy compounds.

  Examples of the thermoplastic resins include polyester resins, polyphenylene sulfide resins, polyphenylene oxide resins, polycarbonate resins, polylactic acid resins, polyacetal resins, polysulfone resins, tetrafluoropolyethylene resins, polyetherimide resins, polyamideimide resins, and polyimide resins. , Polyethersulfone resins, polyetherketone resins, polythioetherketone resins, polyetheretherketone resins, styrene resins such as polystyrene resins and ABS resins, and polyalkylene oxide resins. It is also possible to blend two or more of such thermoplastic resins.

  Various additives include, for example, anti-coloring agents, antioxidants such as hindered phenols and hindered amines, mold release agents, plasticizers, heat stabilizers, lubricants, UV inhibitors, colorants, flame retardants, foaming agents, etc. Is mentioned.

  It is preferable to add a copper compound to the polyamide resin composition because long-term heat resistance can be improved. Examples of the copper compound include cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, cupric iodide, cupric sulfate, cupric nitrate. , Copper phosphate, cuprous acetate, cupric acetate, cupric salicylate, cupric stearate, cupric benzoate and inorganic copper halides and xylylenediamine, 2-mercaptobenzimidazole, benzimidazole And complex compounds. Two or more of these may be blended. Among these, monovalent copper compounds, particularly monovalent copper halide compounds are preferable, and cuprous acetate, cuprous iodide, and the like are preferable. The compounding amount of the copper compound is preferably 0.01 parts by weight or more, more preferably 0.015 parts by weight or more with respect to 100 parts by weight of the polyamide 6 resin (A). On the other hand, the amount of the copper compound is preferably 2 parts by weight or less, and more preferably 1 part by weight or less, from the viewpoint of suppressing coloration due to liberation of metallic copper during molding.

  Moreover, you may mix | blend an alkali halide with a copper compound. Examples of the alkali halide compound include lithium chloride, lithium bromide, lithium iodide, potassium chloride, potassium bromide, potassium iodide, sodium bromide and sodium iodide. Two or more of these may be blended. Particular preference is given to potassium iodide or sodium iodide.

  The temperature-falling crystallization temperature by DSC measurement of the polyamide resin composition is preferably 180 ° C. or higher, and more preferably 183 ° C. or higher. If the temperature drop crystallization temperature of the polyamide resin composition is 180 ° C. or more, in the cooling process from the molten state of the polyamide resin composition, dense and uniform crystals are likely to be formed, resulting in low hydrogen permeability. The temperature-falling crystallization temperature of the polyamide resin composition capable of suppressing the generation of defect points even when high-pressure hydrogen filling and releasing pressure is repeated is preferably 180 ° C. or higher, and more preferably 183 ° C. or higher.

  In addition, in this invention, the temperature fall crystallization temperature by DSC measurement of a polyamide resin composition can be calculated | required with the following method. First, using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer), two-point calibration (indium, lead) and baseline correction are performed. The sample amount was set to 8 to 10 mg, held for 1 minute at a temperature 15 ° C. higher than the temperature showing the maximum value of the melting curve obtained by heating at a heating rate of 20 ° C./min, and then the temperature was lowered to 20 ° C./min. The crystallization exothermic peak temperature observed when cooling at a rate of 30 ° C. is defined as the temperature-falling crystallization temperature. However, when two or more peaks are observed, the temperature corresponding to the largest crystallization exothermic peak is set as the temperature-falling crystallization temperature of the polyamide resin composition.

  Examples of the means for setting the temperature drop crystallization temperature of the polyamide resin composition in the above range include a method using the above-mentioned preferred polyamide resin composition.

  Next, the manufacturing method of the polyamide resin composition of this invention is demonstrated. There is no restriction | limiting in particular as a manufacturing method of the thermoplastic polyamide resin composition of this invention, For example, a polyamide 6 resin (A), an amide-type wax (B), and an impact-resistant material (C) and other components as needed are included. A method of kneading together, a method of kneading an amide wax (B) and, if necessary, an impact resistant material (C) and other components after melting the polyamide 6 resin (A), a polyamide 6 resin (A) and an amide wax Examples include a method of kneading the impact resistant material (C) and other components as necessary after melting (B). As a kneading apparatus, for example, a known kneading apparatus such as a Banbury mixer, a roll, or an extruder can be employed. When the polyamide resin composition of the present invention is blended with other components such as the impact resistant material (C) and various additives, these can be blended at any stage. For example, when the polyamide resin composition of the present invention is produced by a twin screw extruder, the impact resistant material (C) and other components are blended simultaneously when the polyamide 6 resin (A) and the amide wax (B) are blended. A method of blending the impact-resistant material (C) and other components by a method such as side feed during the melt-kneading of the polyamide 6 resin (A) and the amide wax (B), or a polyamide 6 resin (A ) And amide wax (B) are melt-kneaded and then the impact resistant material (C) and other components are blended, or the polyamide 6 resin (A) is blended with the impact resistant material (C) and other components in advance. And a method of blending the amide wax (B) after melt-kneading.

  The polyamide resin composition of the present invention can be molded by any method to obtain a molded product. Examples of the molding method include extrusion molding, injection molding, hollow molding, calendar molding, compression molding, vacuum molding, foam molding, blow molding, and rotational molding. Examples of the molded shape include shapes such as a pellet shape, a plate shape, a fiber shape, a strand shape, a film or sheet shape, a pipe shape, a hollow shape, and a box shape.

  The molded article of the present invention is used for a molded article that comes into contact with high-pressure hydrogen, taking advantage of the excellent feature that generation of defects is suppressed even when high-pressure hydrogen is repeatedly charged and released. The molded product that is in contact with high-pressure hydrogen here is a molded product that is in contact with hydrogen at a pressure higher than normal pressure. Since it has the effect of suppressing the generation of defect points when repeated filling and releasing of high-pressure hydrogen, it is preferably used for molded products that come into contact with hydrogen at a pressure of 20 MPa or higher, and used for molded products that come into contact with hydrogen at 30 MPa or higher. Preferably used. On the other hand, it is preferably used for molded products that come into contact with hydrogen at a pressure of 200 MPa or less, more preferably used for molded products that come into contact with hydrogen at 150 MPa or less, and more preferably used for molded products that come into contact with hydrogen at 100 MPa or less. Examples of molded products that come into contact with high-pressure hydrogen include high-pressure hydrogen on-off valve, high-pressure hydrogen check valve, high-pressure hydrogen pressure-reducing valve, high-pressure hydrogen pressure regulating valve, high-pressure hydrogen seal, high-pressure hydrogen hose, high-pressure hydrogen Tank, high pressure hydrogen tank liner, high pressure hydrogen pipe, high pressure hydrogen packing, high pressure hydrogen pressure sensor, high pressure hydrogen pump, high pressure hydrogen tube, high pressure hydrogen regulator, high pressure hydrogen film, high pressure hydrogen sheet, high pressure Examples include hydrogen fibers and high-pressure hydrogen joints. Among them, on-off valve for high pressure hydrogen, check valve for high pressure hydrogen, pressure reducing valve for high pressure hydrogen, pressure regulating valve for high pressure hydrogen, tank for high pressure hydrogen, tank liner for high pressure hydrogen, packing for high pressure hydrogen, pressure sensor for high pressure hydrogen, It can be preferably used in high-pressure hydrogen containers such as a high-pressure hydrogen pump, a high-pressure hydrogen regulator, and a high-pressure hydrogen joint and its peripheral parts. Among these, it can be particularly preferably used for a high-pressure hydrogen tank.

  The tank liner for high pressure hydrogen can be obtained by molding by any method. Examples of the molding method include extrusion molding, injection molding, hollow molding, calendar molding, compression molding, vacuum molding, foam molding, blow molding, and rotational molding.

  Moreover, the method of forming the tank liner for high pressure hydrogen can mention the method of forming by forming the 2 or more division body which comprises the tank liner for high pressure hydrogen by shaping | molding, and joining these by welding. For example, a method of forming a high-pressure hydrogen tank liner by joining two molded bodies having a shape of a high-pressure hydrogen tank liner divided in half by welding, and a shape in which the high-pressure hydrogen tank liner is divided in half. A method of forming a tank liner for high-pressure hydrogen by joining two molded bodies by welding, two end plates having a semicircular shape, an elliptical shape, etc., covering both ends of the high-pressure hydrogen tank liner, Although the method of forming the tank liner for high pressure hydrogen by joining a part by welding is mentioned, It is not limited to this.

  Examples of the welding include hot plate welding, ultrasonic welding, vibration welding, laser welding, infrared welding, and infrared / vibration welding in which vibration welding is performed after warming a welding portion with infrared rays. Of these, infrared welding and infrared / vibration welding are preferable.

  A particularly preferable embodiment is an embodiment in which a tank liner made of the polyamide resin composition of the present invention is used as a resin liner for a high-pressure hydrogen tank formed by reinforcing the outside of a resin liner with a carbon fiber reinforced resin. That is, the high pressure hydrogen tank of the present invention is a high pressure hydrogen tank in which a carbon fiber reinforced resin (CFRP) reinforcing layer is laminated on the surface layer of a tank liner made of the polyamide resin composition of the present invention.

  It is preferable to laminate a CFRP reinforcing layer on the surface layer of the tank liner, since strength and elastic modulus that can withstand high pressure can be expressed. The CFRP reinforcing layer is composed of carbon fibers and a matrix resin. The carbon fiber preferably has a tensile elastic modulus of 50 to 700 GPa from the viewpoint of bending properties and strength, and more preferably 200 to 700 GPa in view of the specific rigidity. Considering the viewpoint, the one of 200 to 450 GPa is most preferable. Moreover, 1500-7000 MPa is preferable and the tensile strength of a carbon fiber single-piece | unit is preferable, and 3000-7000 MPa is preferable from a viewpoint of specific strength. The density of the carbon fiber is preferably 1.60 to 3.00, more preferably 1.70 to 2.00 from the viewpoint of weight reduction, and most preferably 1.70 to 1.90 from the viewpoint of cost performance. Furthermore, the fiber diameter of the carbon fiber is preferably 5 to 30 μm per strand, more preferably 5 to 20 μm from the viewpoint of handleability, and most preferably 5 to 10 μm from the viewpoint of weight reduction. Carbon fibers may be used alone or in combination with reinforcing fibers other than carbon fibers. Examples of reinforcing fibers other than carbon fibers include glass fibers and aramid fibers. Further, when the ratio of the carbon fiber to the matrix resin is defined by the volume fraction Vf of the carbon fiber in the carbon fiber reinforced resin reinforcing layer material, Vf is preferably 20 to 90% from the viewpoint of rigidity, and from the viewpoint of productivity and required rigidity. To Vf is preferably 40 to 80%.

  The matrix resin constituting the CFRP reinforcing layer may be a thermosetting resin or a thermoplastic resin. When the matrix resin is a thermosetting resin, examples of the main material include an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a phenol resin, a polyurethane resin, and a silicone resin. Only one of these may be used, or two or more may be mixed and used. Epoxy resins are particularly preferred. Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, isocyanate modified bisphenol A type epoxy resin and the like. When a thermosetting resin is employed for the matrix resin, it is possible to add an appropriate curing agent or reaction accelerator to the thermosetting resin component.

  When the matrix resin is a thermoplastic resin, the main materials are polyethylene resin, polypropylene resin, polyvinyl chloride resin, ABS resin, polystyrene resin, AS resin, polyamide resin, polyacetal resin, polycarbonate resin, thermoplastic polyester resin, PPS resin Fluorine resin, polyetherimide resin, polyetherketone resin, polyimide resin and the like. These thermoplastic resins may be used alone, as a mixture of two or more kinds, or as a copolymer. In the case of a mixture, a compatibilizer may be used in combination. In addition, brominated flame retardants, silicon-based flame retardants, red phosphorus, and the like may be added as flame retardants.

  As a method of laminating the CFRP reinforcing layer on the surface layer of the high-pressure hydrogen tank liner, known filament winding (hereinafter referred to as FW) method, tape winding (hereinafter referred to as TW) method, sheet winding (hereinafter referred to as SW) method, hand layup method, RTM The (Resin Transfer Molding) method and the like can be exemplified. Of these molding methods, molding may be performed by only a single method, or two or more molding methods may be combined. A method selected from the FW method, the TW method, and the SW method is preferable from the viewpoints of expression of properties, productivity, and moldability. These FW method, SW method and TW method are basically the same molding method from the viewpoint of applying a matrix resin to a strand-like carbon fiber and laminating it on the liner. The name is different depending on whether it is wound in a filament (thread) form, a tape (tape form in which yarns are bundled to some extent) form, or a sheet (sheet form in which tapes are bundled to some extent). Here, the details of the most basic FW method will be described, but the contents can also be applied to the TW method and the SW method.

  In the FW method, when the matrix resin is a thermosetting resin, it is possible to wrap the carbon fiber in a state where the resin has been applied in advance (uncured) directly around the liner, or apply the resin to the carbon fiber immediately before wrapping around the liner. It is also possible to do. In these cases, after wrapping carbon fiber and uncured matrix resin around the liner, it is necessary to perform resin curing treatment under conditions suitable for the resin used in a batch furnace (oven) or continuous curing furnace in order to cure the resin. There is.

  In the FW method, when the matrix resin is a thermoplastic resin, it is possible to wind a carbon fiber previously coated (impregnated) with a resin to form a high-pressure hydrogen tank shape. In this case, it is necessary to raise the temperature of the carbon fiber coated with the resin to a temperature equal to or higher than the melting point of the thermoplastic resin immediately before being wound around the liner. It is also possible to apply a thermoplastic resin melted in carbon fibers immediately before winding around the liner. In this case, the resin curing step as applied to the thermosetting resin is unnecessary.

  When obtaining the high-pressure hydrogen tank of the present invention by the FW method, TW method, SW method, etc., the most important thing is the fiber orientation design of the carbon fiber. In the FW method, the TW method, and the SW method, a carbon fiber strand (continuous fiber) or a prepreg in which a carbon fiber strand is impregnated with a resin is wound around a liner and molded. At the time of designing, it is preferable to design so as to satisfy rigidity and strength satisfying the required characteristics, with the continuous fiber direction and the laminated thickness in the liner body as design factors.

  Moreover, as a tank for high pressure hydrogen, it is preferable that the valve is inserted in the tank liner by insert molding. It is preferable to integrate the valve with the tank liner by insert molding since the airtightness of the high-pressure hydrogen is increased. Here, the valve functions as a high-pressure hydrogen filling port and a discharge port. Examples of the material of the metal part used as the valve include carbon steel, manganese steel, chrome molybdenum steel, stainless steel, and aluminum alloy. Examples of carbon steel include carbon steel pipe for pressure piping, carbon steel pipe for high pressure piping, steel pipe for low temperature piping, and carbon steel for machine structure. Examples of manganese steel include seamless steel pipes for high-pressure gas containers, manganese steel materials for machine structures, and manganese chromium steel materials. Examples of chrome molybdenum steel and low alloy steel include seamless steel pipes for high-pressure gas containers, alloy steel pipes for machine structures, nickel chrome molybdenum steel materials, and chrome molybdenum steel materials. Examples of stainless steel include stainless steel forgings for pressure, stainless steel pipes for piping, stainless steel bars, hot rolled stainless steel plates and steel strips, cold rolled stainless steel plates and steel strips. Examples of the aluminum alloy include aluminum and aluminum alloy plates, strips, bars, wires, seamless pipes, and forged products. For carbon steel, annealing, normalizing, for manganese steel, normalizing, quenching and tempering, for chromium molybdenum steel and low alloy steel, quenching and tempering, stainless steel For the aluminum alloy, a material subjected to hardening and tempering may be applied to the aluminum alloy. Furthermore, for the aluminum alloy, a solution subjected to solution treatment and T6 aging treatment may be applied.

  The most preferred embodiment of the high-pressure hydrogen tank of the present invention is a high-pressure tank in which a CFRP reinforcing layer is laminated on the surface layer of a tank liner comprising the polyamide resin composition of the present invention, and a valve is inserted into the tank liner. It is a tank for hydrogen.

  Hereinafter, the effects of the present invention will be described more specifically with reference to examples. In addition, this invention is not limited to the following Example. Evaluation in each example and comparative example was performed by the following method.

(1) High-pressure hydrogen filling and depressurization repetition characteristics (defects)
From the pellets obtained in each Example and Comparative Example, using an injection molding machine “SU75DUZ-C250” manufactured by Sumitomo Heavy Industries, Ltd., cylinder temperature: 240 ° C., mold temperature: 80 ° C., injection speed 10 mm / A cylindrical test piece having a diameter of 29 mm and a height of 12.6 mm was injection-molded under molding conditions of a second, a holding pressure of 15 MPa, a holding pressure time of 15 seconds, and a cooling time of 15 seconds.

  The obtained specimen was subjected to X-ray CT analysis using “TDM1000-IS” manufactured by Yamato Scientific Co., Ltd., and the presence or absence of defect points was observed. After putting a test piece having no defect in the autoclave, hydrogen gas was injected into the autoclave to a pressure of 30 MPa over 3 minutes, held for 2 hours, and then reduced to normal pressure over 1 minute. This was repeated for 700 cycles as one cycle. The test piece after 700 cycles was subjected to X-ray CT analysis using “TDM1000-IS” manufactured by Yamato Scientific Co., Ltd., and the presence or absence of defect points of 10 μm or more was observed.

(2) Decreasing crystallization temperature of polyamide resin composition About pellets obtained in each example and comparative example, using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer), two-point calibration (indium, lead), After performing the baseline correction, the sample amount was set to 8 to 10 mg, and held for 1 minute at a temperature 15 ° C. higher than the temperature showing the maximum value of the melting curve obtained by heating at a heating rate of 20 ° C./min. Then, it cooled to 30 degreeC on the conditions of temperature-fall rate 20 degree-C / min. The peak temperature of the crystallization exotherm observed in this cooling step was defined as the cooling crystallization temperature.

(3) Releasability Cylinder temperature: 240 ° C., mold temperature: 80 from pellets obtained in each example and comparative example, using an injection molding machine “SE75DUZ-C250” manufactured by Sumitomo Heavy Industries, Ltd. A square plate molded product of 80 mm × 80 mm × thickness 3 mm was injection molded under the molding conditions of ° C., injection speed: 40 mm / second, holding pressure: 20 MPa, and cooling time: 20 seconds. The presence or absence of sticking to the mold was confirmed during injection molding.

(4) Heat cycle resistance The pellets obtained in each Example and Comparative Example were manufactured using an injection molding machine “NEX1000” manufactured by Nissei Plastic Industry Co., Ltd., cylinder temperature: 240 ° C., mold temperature: 80 ° C., Under molding conditions of an injection speed of 100 mm / second and a cooling time of 20 seconds, a metal core of 47 mm × 47 mm × 27 mm was overmolded with a thickness of 1.5 mm.

  The obtained three metal / resin composite molded articles were allowed to stand at a temperature of −60 ° C. for 1 hour, and then left at 90 ° C. for 1 hour, and the composite molded article was visually observed to determine the presence or absence of cracks. This operation was repeated, and the number of cycles in which all three composite molded articles were broken was 500 or more, A was 200 to 499, B was 199, and C was 199.

(5) Impact resistance Cylinder temperature: 240 ° C., mold temperature: 80, using an injection molding machine “SE75DUZ-C250” manufactured by Sumitomo Heavy Industries, Ltd. from the pellets obtained in each example and comparative example. An Izod impact molded piece with a notch conforming to ASTM D256 was injection molded under the molding conditions of ° C., injection speed: 40 mm / second, holding pressure: 20 MPa, and cooling time: 20 seconds.

  The seven notched Izod impact molded pieces obtained were evaluated for impact resistance (notched Izod impact strength) at 23 ° C. according to ASTM D256. The average value of the seven measured was taken as impact resistance.

The raw materials and abbreviations used in each example and comparative example are shown below.
PA6: polyamide 6 resin (melting point 223 ° C., relative viscosity 2.70 at 25 ° C. in 98% concentrated sulfuric acid solution having a resin concentration of 0.01 g / ml)
PA66: polyamide 66 resin (melting point 263 ° C., relative viscosity 2.70 at 25 ° C. in 98% concentrated sulfuric acid solution having a resin concentration of 0.01 g / ml)
PA6 / PA66 copolymer: Polyamide 6 / polyamide 66 copolymer (melting point 190 ° C., relative viscosity 4.20 at 25 ° C. in 98% concentrated sulfuric acid solution having a resin concentration of 0.01 g / ml)
Amide wax 1: ethylenediamine / stearic acid / sebacic acid polycondensate ““ light amide ”WH-215” (manufactured by Kyoeisha Chemical Co., Ltd., melting point 215 ° C.)
Amide wax 2: ethylenediamine / stearic acid / sebacic acid polycondensate ““ light amide ”WH-255” (manufactured by Kyoeisha Chemical Co., Ltd., melting point 255 ° C.)
Fatty acid ester: Ethylene glycol dimontanate “Licowax” E (manufactured by Clariant Japan Co., Ltd.)
Organic nucleating agent: N, N ′, N ″ -tris (2-methylcyclohexane-1-yl) propane-1-3-3 triylcarboxamide ““ Rikaclear ”(registered trademark) PC-1” (New Nippon Rika ( Made by Co., Ltd.)
Inorganic nucleating agent: Talc "" MicroAce "(registered trademark) P-6" (Nippon Talc Co., Ltd., median diameter (D50) 4.0 [mu] m)
Impact-resistant material 1: maleic anhydride-modified ethylene / 1-butene copolymer “Toughmer (registered trademark) MH7020” (manufactured by Mitsui Chemicals, Inc.)
Impact-resistant material 2: Glycidyl methacrylate-modified polyethylene copolymer “Bond First” (registered trademark) 7L (manufactured by Sumitomo Chemical Co., Ltd.)
Impact-resistant material 3: Ionomer “High Milan” (registered trademark) 1706 (manufactured by DuPont).
Impact-resistant material 4: maleic anhydride-modified ethylene / 1-butene copolymer “Toughmer (registered trademark) MH5040” (manufactured by Mitsui Chemicals, Inc.)

[Examples 1-9, Comparative Examples 1-7]
Each raw material described in Table 1 and Table 2 is a screw arrangement in which the cylinder temperature is set to 240 ° C., one kneading zone is provided, and the screw rotational speed is 150 rpm (TEX30α- manufactured by JSW) 35BW-7V) (L / D = 45 (where L is the length from the raw material supply port to the discharge port)) and melt-kneaded. The gut discharged from the die at a rate of 20 kg / h was rapidly cooled by passing through a cooling bath filled with water adjusted to 10 ° C. over 10 seconds, and then pelletized with a strand cutter to obtain pellets. . The obtained pellets were vacuum-dried with a vacuum dryer at a temperature of 80 ° C. for 12 hours, and the results of evaluation using the pellets after drying were described in Tables 1 and 2.

  From the above results, the polyamide resin composition obtained by blending the polyamide 6 resin (A) and the amide wax (B) has a high crystallization temperature, and the crystallization from the molten state proceeds quickly, so the crystallization speed is high. It has been found that a molded product obtained by molding such a polyamide resin composition is fast, and even when high-pressure hydrogen filling and releasing pressure are repeated, generation of defects is suppressed and the mold release property is excellent.

  Furthermore, it turned out that the molded article obtained by shape | molding the polyamide resin composition obtained by mix | blending an impact-resistant material (C) is excellent in heat cycle resistance.

The polyamide resin composition of the present invention has a high crystallization temperature, and the crystallization from a molten state progresses quickly, so that the crystallization speed increases, and the occurrence of defect points is suppressed even when high-pressure hydrogen filling and releasing are repeated. In addition, it has excellent mold release, which is important in injection molding. Molded articles formed by molding the polyamide resin composition of the present invention can be widely used for molded articles that come into contact with high-pressure hydrogen utilizing these characteristics.

Claims (9)

A polyamide resin composition for molded articles that comes into contact with high-pressure hydrogen, comprising 0.01 to 10 parts by weight of an amide wax (B) per 100 parts by weight of a polyamide 6 resin (A). The polyamide resin composition according to claim 1, wherein the melting point of the amide wax (B) by DSC measurement is equal to or higher than the melting point of the polyamide 6 resin (A). Furthermore, the polyamide resin composition of Claim 1 or 2 formed by mix | blending 1-50 weight part of impact-resistant materials (C) with respect to 100 weight part of polyamide 6 resin (A). The polyamide resin composition according to claim 3, wherein the impact-resistant material (C) comprises an ethylene / α-olefin copolymer modified with an unsaturated carboxylic acid and / or a derivative thereof. The polyamide resin composition according to any one of claims 1 to 4, wherein the temperature-falling crystallization temperature by DSC measurement is 180 ° C or higher. The molded article which contacts the high pressure hydrogen which consists of the polyamide resin composition in any one of Claims 1-5. A tank liner for high pressure hydrogen comprising the polyamide resin composition according to any one of claims 1 to 5. A tank for high pressure hydrogen, wherein a carbon fiber reinforced resin reinforcing layer is laminated on a surface layer of a tank liner made of the polyamide resin composition according to any one of claims 1 to 5. The high-pressure hydrogen tank according to claim 8, wherein a valve is inserted into the tank liner.