Thermoplastic resin composition for hydrogen tank liner and hydrogen tank

Abstract

To provide a thermoplastic resin composition for hydrogen tank liners that exhibits superior gas barrier performance and superior yield point elongation at low temperature.SOLUTION: A thermoplastic resin composition for a hydrogen tank liner comprises an aliphatic polyamide (A), a semi-aromatic polyamide (B), and an elastomer (C), wherein the aliphatic polyamide (A) has a polymethylene chain of 10 or more carbon atoms sandwiched between two adjacent amide bonds, the aliphatic polyamide (A) and the semi-aromatic polyamide (B) constitute a matrix, and the elastomer (C) constitutes a domain.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermoplastic resin composition for a hydrogen tank liner and a hydrogen tank having a liner made of the thermoplastic resin composition. [Background technology]

[0002] Hydrogen tank liners require high gas barrier properties because they are constantly under high pressure. Furthermore, the temperature inside the tank drops due to adiabatic expansion, so the liner is exposed to low temperatures. Because the liner undergoes deformation due to differences in the thermal expansion coefficient with adjacent materials, it requires high yield point elongation at low temperatures.

[0003] Japanese Patent No. 4588078 (Patent Document 1) discloses a material for hydrogen tank liners made of a polyamide resin composition containing polyamide 6, polyamide 6 / 66, and maleic anhydride-modified EBR. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4588078 Summary of the Invention [Problem to be solved by the invention]

[0005] The hydrogen tank liner material disclosed in Patent Document 1 has excellent gas barrier properties, but its low low-temperature yield point elongation places limitations on the shape design of the tank. The present invention provides a thermoplastic resin composition for hydrogen tank liners that is excellent in both gas barrier properties and low-temperature yield point elongation. [Means for solving the problem]

[0006] The present invention (I) is a thermoplastic resin composition for hydrogen tank liners, comprising an aliphatic polyamide (A), a semi-aromatic polyamide (B), and an elastomer (C), wherein the aliphatic polyamide (A) has a polymethylene chain having 10 or more carbon atoms sandwiched between two adjacent amide bonds, the aliphatic polyamide (A) and the semi-aromatic polyamide (B) constitute a matrix, and the elastomer (C) constitutes a domain. The present invention (II) is a hydrogen tank having a liner made of the thermoplastic resin composition of the present invention (I).

[0007] The present invention includes the following embodiments. [1] A thermoplastic resin composition for hydrogen tank liners, comprising an aliphatic polyamide (A), a semi-aromatic polyamide (B), and an elastomer (C), wherein the aliphatic polyamide (A) has a polymethylene chain having 10 or more carbon atoms sandwiched between two adjacent amide bonds, the aliphatic polyamide (A) and the semi-aromatic polyamide (B) constitute a matrix, and the elastomer (C) constitutes a domain. [2] The thermoplastic resin composition for a hydrogen tank liner according to [1], characterized in that the matrix contains a phase of aliphatic polyamide (A) and a phase of semi-aromatic polyamide (B), and the content of elastomer (C) in the aliphatic polyamide (A) phase is higher than the content of elastomer (C) in the semi-aromatic polyamide (B) phase. [3] The thermoplastic resin composition for a hydrogen tank liner according to [1], wherein the mass ratio of the aliphatic polyamide (A) to the semi-aromatic polyamide (B) is 95:5 to 40:60. [4] The thermoplastic resin composition for a hydrogen tank liner according to [1], wherein the content of the elastomer (C) in the thermoplastic resin composition is 5 to 50 mass %. [5] Temperature: 270°C, shear rate: 243 s -1 The melt viscosity η of aliphatic polyamide (A) at A Melt viscosity η of semi-aromatic polyamide (B) versus B The ratio of η B / η AThe thermoplastic resin composition for a hydrogen tank liner according to [1], wherein the value of the tensile strength is 0.20 to 0.95. [6] Thermoplastic resin composition temperature 270°C, shear rate 243 s -1 The thermoplastic resin composition for a hydrogen tank liner according to [1], characterized in that the melt viscosity η at 2000°C is 700 to 1500 Pa·s. [7] The thermoplastic resin composition for a hydrogen tank liner according to [1], wherein the aliphatic polyamide (A) is polyamide 11. [8] The thermoplastic resin composition for a hydrogen tank liner according to [1], wherein the semi-aromatic polyamide (B) is polyamide MXD6. [9] The thermoplastic resin composition for hydrogen tank liners according to [1], characterized in that the elastomer (C) comprises at least one selected from the group consisting of acid-modified or epoxy-modified polyolefin-based elastomers, polystyrene-based elastomers, and acid-modified or epoxy-modified polystyrene-based elastomers.

[10] A hydrogen tank having a liner made of the thermoplastic resin composition according to [1]. [Effects of the Invention]

[0008] The thermoplastic resin composition for a hydrogen tank liner of the present invention is excellent in gas barrier properties and low-temperature yield point elongation. DETAILED DESCRIPTION OF THE INVENTION

[0009] The thermoplastic resin composition for a hydrogen tank liner of present invention (I) is a thermoplastic resin composition comprising an aliphatic polyamide (A), a semi-aromatic polyamide (B), and an elastomer (C), characterized in that the aliphatic polyamide (A) has a polymethylene chain having 10 or more carbon atoms sandwiched between two adjacent amide bonds, the aliphatic polyamide (A) and the semi-aromatic polyamide (B) constitute a matrix, and the elastomer (C) constitutes a domain.

[0010] The thermoplastic resin composition includes an aliphatic polyamide, a semi-aromatic polyamide, and an elastomer.

[0011] Aliphatic polyamides have a polymethylene chain of 10 or more carbon atoms sandwiched between two adjacent amide bonds (-NH-CO- or -CO-NH-). A polymethylene chain with 10 or more carbon atoms is represented by the following chemical formula: -(CH2) n - (where n ≥ 10) The polymethylene chain preferably has 10, 11 or 12 carbon atoms, and more preferably has 10 carbon atoms. The aliphatic polyamide may have a polymethylene chain having less than 10 carbon atoms sandwiched between two adjacent amide bonds, as long as it has a polymethylene chain having 10 or more carbon atoms sandwiched between two adjacent amide bonds. A specific example of an aliphatic polyamide having a polymethylene chain having 10 or more carbon atoms sandwiched between two adjacent amide bonds is polyamide 11 (-[-NH-(CH2) 10 -CO-] m -), Polyamide 12 (-[-NH-(CH2) 11 -CO-] m -), Polyamide 612 (-[-NH-(CH2)6-NH-CO-(CH2) 10 -CO-] m -), Polyamide 1010 (-[-NH-(CH2) 10 -NH-CO-(CH2)8-CO-] m -), Polyamide 1012 (-[-NH-(CH2) 10 -NH-CO-(CH2) 10 -CO-] m -), polyamide 6 / 12 copolymer, etc. (where m represents a positive integer). The aliphatic polyamide is preferably polyamide 11. Polyamide 11 is a polyamide having a structure of -[-NH-(CH) 10 -CO-] m - (where m is a positive integer), and has a polymethylene chain with 10 carbon atoms sandwiched between two adjacent amide bonds. When the aliphatic polyamide is polyamide 11, the low-temperature yield point elongation is particularly excellent.

[0012] Semi-aromatic polyamides are polyamides in which either the diamine component or the dicarboxylic acid component constituting the polyamide is an aromatic compound. That is, semi-aromatic polyamides are classified into two types: semi-aromatic polyamides composed of an aromatic diamine component and an aliphatic dicarboxylic acid component, and semi-aromatic polyamides composed of an aliphatic diamine component and an aromatic dicarboxylic acid component, but either type is acceptable.

[0013] Examples of aromatic diamine components constituting semi-aromatic polyamides consisting of an aromatic diamine component and an aliphatic dicarboxylic acid component include, but are not limited to, metaxylylenediamine, paraxylylenediamine, bis(4-aminophenyl)ether, paraphenylenediamine, and bis(aminomethyl)naphthalene. Examples of the aliphatic dicarboxylic acid component constituting the semi-aromatic polyamide composed of an aromatic diamine component and an aliphatic dicarboxylic acid component include, but are not limited to, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. Examples of semi-aromatic polyamides consisting of an aromatic diamine component and an aliphatic dicarboxylic acid component include semi-aromatic polyamides consisting of at least one of the aromatic diamine components and at least one of the aliphatic dicarboxylic acid components, and polyamide MXD6 is preferred. The semi-aromatic polyamide is preferably polyamide MXD6. When the semi-aromatic polyamide is polyamide MXD6, the gas barrier property and processability are particularly excellent.

[0014] Examples of the aliphatic diamine component constituting the semi-aromatic polyamide, which is composed of an aliphatic diamine component and an aromatic dicarboxylic acid component, include, but are not limited to, 1,2-ethanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 2-methyl-1,5-pentanediamine, and 2-methyl-1,8-octanediamine. Examples of the aromatic dicarboxylic acid component constituting the semi-aromatic polyamide composed of an aliphatic diamine component and an aromatic dicarboxylic acid component include, but are not limited to, terephthalic acid, isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid. The semi-aromatic polyamide composed of an aliphatic diamine component and an aromatic dicarboxylic acid component may be a semi-aromatic polyamide composed of at least one of the aliphatic diamine components and at least one of the aromatic dicarboxylic acid components, and preferably polyamide 6T, polyamide 6I, polyamide 9T, or polyamide 10T.

[0015] Examples of elastomers include, but are not limited to, natural rubber (NR), styrene butadiene rubber (SBR), chloroprene rubber (CR), acrylonitrile rubber (NBR), butyl rubber (IIR), ethylene propylene rubber (EPDM), urethane rubber, silicone rubber, fluororubber, chlorosulfonated polyethylene rubber, and thermoplastic elastomers. Examples of thermoplastic elastomers include, but are not limited to, polyolefin elastomers, polystyrene elastomers, urethane elastomers, vinyl chloride elastomers, polyamide elastomers, and polyester elastomers. Examples of polyolefin elastomers include, but are not limited to, ethylene-α-olefin copolymers (wherein the α-olefin is an α-olefin having 3 to 20 carbon atoms, preferably an α-olefin having 3 to 8 carbon atoms), propylene-α-olefin copolymers (wherein the α-olefin is an α-olefin having 4 to 20 carbon atoms, preferably an α-olefin having 4 to 8 carbon atoms), ethylene-α,β-unsaturated carboxylic acid copolymers (wherein the α,β-unsaturated carboxylic acid is preferably acrylic acid or methacrylic acid), and ethylene-α,β-unsaturated carboxylic acid ester copolymers (wherein the α,β-unsaturated carboxylic acid ester is preferably an ester of acrylic acid or methacrylic acid with an alcohol having 1 to 10 carbon atoms, more preferably the methyl or ethyl ester of acrylic acid or methacrylic acid). Examples of polystyrene elastomers include, but are not limited to, styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene block copolymer (SEP), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), and styrene-isobutylene-styrene block copolymer (SIBS). The elastomer may be acid- or epoxy-modified, and is preferably acid- or epoxy-modified. The acid-modified elastomer refers to one modified with a carboxylic acid or its derivative, preferably maleic anhydride. The epoxy-modified elastomer refers to one into which an epoxy group has been introduced. The acid- or epoxy-modification can increase the affinity for polyamide. The elastomer preferably contains at least one selected from the group consisting of acid- or epoxy-modified polyolefin elastomers, polystyrene elastomers, and acid- or epoxy-modified polystyrene elastomers. When the elastomer contains at least one selected from the group consisting of acid- or epoxy-modified polyolefin elastomers, polystyrene elastomers, and acid- or epoxy-modified polystyrene elastomers, the low-temperature yield point elongation is particularly excellent. Acid-modified polyolefin elastomers are commercially available, and examples of commercially available products include Admer (registered trademark) and Tafmer (registered trademark) MH series manufactured by Mitsui Chemicals, Inc. Polystyrene-based elastomers are commercially available, and examples of commercially available products include Tufprene (registered trademark), Tuftec (registered trademark), and SOE (registered trademark) manufactured by Asahi Kasei Corporation, and Septon (registered trademark) manufactured by Kuraray Co., Ltd. Acid-modified polystyrene elastomers are commercially available, and examples of commercially available products include Tuftec (registered trademark) M series manufactured by Asahi Kasei Corporation and Kraton (registered trademark) FG polymer manufactured by Kraton Corporation. Epoxy-modified polystyrene elastomers are commercially available, and examples of commercially available products include Epofriend (registered trademark) manufactured by Daicel Corporation.

[0016] The aliphatic polyamide (A) and the semi-aromatic polyamide (B) constitute the matrix, and the elastomer (C) constitutes the domains, i.e., the thermoplastic resin composition has an islands-in-a-sea structure. The matrix preferably comprises a phase of an aliphatic polyamide (A) and a phase of a semi-aromatic polyamide (B). The content of elastomer (C) in the aliphatic polyamide (A) phase is preferably higher than the content of elastomer (C) in the semi-aromatic polyamide (B) phase, i.e., elastomer (C) is preferably distributed more in the aliphatic polyamide (A) phase than in the semi-aromatic polyamide (B) phase. By having such a morphology, the thermoplastic resin composition has a good balance between gas barrier properties and low-temperature yield point elongation. The phase structure can be observed by atomic force microscopy (AFM).

[0017] The mass ratio of the aliphatic polyamide (A) to the semi-aromatic polyamide (B) is preferably 95:5 to 40:60, more preferably 90:10 to 50:50, and even more preferably 85:15 to 60:40. When the mass ratio of the aliphatic polyamide (A) to the semi-aromatic polyamide (B) is within this range, the low-temperature yield point elongation is particularly excellent.

[0018] The content of the elastomer (C) in the thermoplastic resin composition is preferably 5 to 50 mass%, more preferably 10 to 45 mass%, and even more preferably 15 to 40 mass%. When the content of the elastomer (C) is within this range, the balance between the gas barrier property and the low-temperature yield point elongation is particularly excellent.

[0019] Temperature: 270°C, shear rate: 243 s -1 The melt viscosity η of aliphatic polyamide (A) at A Melt viscosity η of semi-aromatic polyamide (B) versus B The ratio of η B / η A (hereinafter referred to as “melt viscosity ratio η B / η A The melt viscosity ratio η is preferably 0.20 to 0.95, more preferably 0.23 to 0.80, and even more preferably 0.25 to 0.70. B / η A When the value is in this range, the balance of physical properties and processability are particularly excellent.

[0020] Thermoplastic resin composition temperature: 270°C, shear rate: 243 s -1 The melt viscosity η in this range is preferably 700 to 1500 Pa·s, more preferably 850 to 1400 Pa·s, and even more preferably 900 to 1300 Pa·s. When the melt viscosity η of the thermoplastic resin composition is in this range, it is particularly suitable for molding.

[0021] The hydrogen tank of the present invention (II) has a liner made of the thermoplastic resin composition of the present invention (I). The hydrogen tank may have the same structure as a conventionally used hydrogen tank, except for the liner. The liner is a layer that coats the inside surface of the hydrogen tank. The thickness of the liner is not limited, but is preferably 0.1 to 15 mm, more preferably 0.3 to 12 mm, and even more preferably 0.5 to 10 mm. The liner can be formed by a conventional method, for example, blow molding, rotational molding, or injection molding. The hydrogen tank of the present invention (II) can be suitably used as a hydrogen tank mounted on an automobile equipped with a fuel cell that uses hydrogen as fuel, although this is not a limitation. [Example]

[0022] [raw materials] The raw materials used in the following examples and comparative examples are as follows: PA6: UBE Corporation's polyamide 6 "UBE Nylon" (registered trademark) 1022B (melt viscosity: 330 Pa s) PA6 / 66: UBE Corporation's polyamide 6 / 66 copolymer "UBE Nylon" (registered trademark) 5023B (melt viscosity: 240 Pa·s) PA11(1): Polyamide 11 "RILSAN" (registered trademark) BESNOTL manufactured by Arkema Inc. (melt viscosity: 410 Pa s) PA11(2): Polyamide 11 "RILSAN" (registered trademark) BMNO manufactured by Arkema (melt viscosity: 90 Pa·s) PAMXD6(1): Polyamide MXD6 "MX Nylon" S6121 (melt viscosity: 230 Pa·s) manufactured by Mitsubishi Gas Chemical Co., Ltd. PAMXD6(2): Polyamide MXD6 "MX Nylon" S6007 (melt viscosity: 120 Pa·s) manufactured by Mitsubishi Gas Chemical Co., Ltd. PAMXD6(3): Polyamide MXD6 "MX Nylon" S6001 (melt viscosity: 70 Pa·s) manufactured by Mitsubishi Gas Chemical Co., Ltd. MahEBR: Maleic anhydride-modified ethylene-1-butene copolymer "Tafmer" (registered trademark) MH7010 manufactured by Mitsui Chemicals, Inc. SEBS: Styrene-ethylene-butylene-styrene block copolymer "Tuftec" (registered trademark) H1041 manufactured by Asahi Kasei Corporation MahSEBS: Maleic anhydride-modified styrene-ethylene-butylene-styrene block copolymer "TUFTECH" (registered trademark) M1913 manufactured by Asahi Kasei Corporation

[0023] [Preparation of Thermoplastic Resin Composition] The raw materials were introduced into a twin-screw kneading extruder (manufactured by The Japan Steel Works, Ltd.) with the cylinder temperature set to 20°C above the melting point of the thermoplastic resin, in the formulations shown in Tables 1 and 2, and melt-kneaded for a residence time of about 5 minutes. The molten mixture was extruded in the form of strands from a die attached to the discharge port. The resulting strand-like extrudate was pelletized using a resin pelletizer to obtain a pelletized thermoplastic resin composition.

[0024] The phase structure of the prepared thermoplastic resin composition was observed, and the oxygen permeability coefficient and low-temperature yield point elongation were measured, and the extrusion processability was evaluated. The measurement and evaluation results are shown in Tables 1 and 2. The measurement and evaluation methods for each measurement and evaluation item are as follows:

[0025] [Observation of phase structure] The pelletized thermoplastic resin composition was molded into a sheet with an average thickness of 2.0 mm using a 40 mmφ single-screw extruder with a 200 mm wide T-type die (Pla Giken Co., Ltd.), with the cylinder and die temperatures set to the melting point of the thermoplastic resin + 20°C, a cooling roll temperature of 50°C, and a take-up speed of 1 m / min. This sheet was cut, and a surface perpendicular to the extrusion direction was made with a razor. After cooling with liquid nitrogen, a smooth surface was made with a diamond knife. Phase images of this surface were observed using an Asylum Research AFM MFP3D in tapping mode. From the observation results, it was confirmed whether the elastomer domains were more prevalent in the semi-aromatic polyamide phase (low phase matrix) or the aliphatic polyamide phase (high phase matrix). In Tables 1 and 2, "A" indicates a case where the elastomer (C) is present in a larger amount in the aliphatic polyamide (A) phase (i.e., a case where the content of elastomer (C) in the aliphatic polyamide (A) phase is higher than the content of elastomer (C) in the semi-aromatic polyamide (B) phase), "B" indicates a case where the elastomer (C) is present in a larger amount in the semi-aromatic polyamide (B) phase (i.e., a case where the content of elastomer (C) in the semi-aromatic polyamide (B) phase is higher than the content of elastomer (C) in the aliphatic polyamide (A) phase), and "indistinguishable" indicates a case where it was impossible to distinguish whether the elastomer was present in a larger amount in the aliphatic polyamide (A) phase or the semi-aromatic polyamide (B) phase.

[0026] [Oxygen permeability measurement] The pelletized thermoplastic resin composition was extruded into a film with an average thickness of 0.2 mm using a 40 mm diameter single-screw extruder (Pla Giken Co., Ltd.) equipped with a 550 mm wide T-type die, with the cylinder and die temperatures set to the melting point of the material with the highest melting point in the thermoplastic resin composition + 20°C, a cooling roll temperature of 50°C, and a take-up speed of 3 m / min. This film was cut to a predetermined size and measured for oxygen permeability (unit: mm cc / (m)) using OXTRAN 1 / 50 manufactured by MOCON under conditions of a temperature of 21°C and a relative humidity of 0%. 2 The oxygen permeability coefficient has been confirmed to correlate with the hydrogen permeability coefficient, and can be used as an index of the hydrogen permeability coefficient. Oxygen permeability coefficient is 0.024 mm·cc / (m 2·day·mmHg) (less than 90% of Comparative Example 1), it is judged to have gas barrier properties that allow a reduction in thickness (weight) to be expected.

[0027] [Measurement of low-temperature yield point elongation] The pelletized thermoplastic resin composition was molded into a sheet with an average thickness of 2.0 mm using a 40 mmφ single-screw extruder with a 200 mm wide T-type die (Pla Giken Co., Ltd.), with the cylinder and die temperatures set to the melting point of the thermoplastic resin + 20°C, a cooling roll temperature of 50°C, and a take-up speed of 1 m / min. According to JIS K6251:2017 "Vulcanized rubber and thermoplastic rubber - Determination of tensile properties," a dumbbell-shaped No. 3 was punched out from this sheet and a tensile test was carried out at a temperature of -40°C and a speed of 100 mm / min. The yield point elongation was calculated from the obtained results and was taken as the low-temperature yield point elongation. If the low-temperature yield point elongation is 11% or more (1.25 times or more that of Comparative Example 2), it is judged that there is an effect that can be expected to improve the degree of freedom in shape design.

[0028] [Evaluation of extrusion processability] The pelletized thermoplastic resin composition was melt-extruded into a sheet with an average thickness of 2.0 mm using a 40 mmφ single-screw extruder with a 200 mm wide T-die (Pla Giken Co., Ltd.) with the cylinder and die temperatures set to the melting point of the thermoplastic resin + 20°C, a cooling roll temperature of 50°C, and a take-up speed of 1 m / min. When the sheet was melt-extruded, a 100 cm length was cut from the sheet 30 minutes after the start of extrusion, and the thickness variations in the extrusion direction and width direction were measured. An index was calculated with Comparative Example 1 (standard) set at 100. When the index was less than 110, the thickness variation was not extremely large or the variation was small compared to Comparative Example 1, and the result was judged as "excellent." When the index was 110 or more but less than 125, the result was slightly inferior to Comparative Example 1, but had sufficient processability, and the result was judged as "good." When the index was 125 or more but less than 140, the processability was poor, but was at an acceptable level for manufacturing, and the result was judged as "passable." When the index was 140 or more, there was a high risk of it affecting the quality, and the result was judged as "fail."

[0029] [Melt viscosity measurement] After drying the thermoplastic resin composition or thermoplastic resin at 90°C for 8 hours, the melt viscosity (Pa·s) as a function of shear rate was measured using a capillary rheometer under conditions of a temperature of 270°C, a capillary length of 10 mm, and a capillary inner diameter of 1 mm. The piston speed was varied and the load was detected. At a shear rate of 243 s -1 The melt viscosity at a piston speed of 20 mm / min, which corresponds to

[0030] [Table 1]

[0031] [Table 2]

[0032] The present disclosure encompasses the following inventions. Invention [1] A thermoplastic resin composition for hydrogen tank liners, comprising an aliphatic polyamide (A), a semi-aromatic polyamide (B), and an elastomer (C), wherein the aliphatic polyamide (A) has a polymethylene chain having 10 or more carbon atoms sandwiched between two adjacent amide bonds, the aliphatic polyamide (A) and the semi-aromatic polyamide (B) constitute a matrix, and the elastomer (C) constitutes a domain. Invention [2] A thermoplastic resin composition for a hydrogen tank liner according to invention [1], characterized in that the matrix contains a phase of aliphatic polyamide (A) and a phase of semi-aromatic polyamide (B), and the content of elastomer (C) in the aliphatic polyamide (A) phase is higher than the content of elastomer (C) in the semi-aromatic polyamide (B) phase. Invention [3] A thermoplastic resin composition for hydrogen tank liners according to invention [1] or [2], characterized in that the mass ratio of the aliphatic polyamide (A) to the semi-aromatic polyamide (B) is 95:5 to 40:60. Invention [4] A thermoplastic resin composition for a hydrogen tank liner according to any one of inventions [1] to [3], characterized in that the content of the elastomer (C) in the thermoplastic resin composition is 5 to 50 mass%. Invention [5] Temperature 270℃, shear rate 243s -1 The melt viscosity η of aliphatic polyamide (A) at A Melt viscosity η of semi-aromatic polyamide (B) versus B The ratio (η B / η A ) is 0.20 to 0.95. Invention [6] Thermoplastic resin composition temperature 270 ° C, shear rate 243 s -1 The thermoplastic resin composition for a hydrogen tank liner according to any one of inventions [1] to [5], characterized in that the melt viscosity η in the thermoplastic resin composition for a hydrogen tank liner is 700 to 1500 Pa·s. Invention [7] A thermoplastic resin composition for a hydrogen tank liner according to any one of inventions [1] to [6], wherein the aliphatic polyamide (A) is polyamide 11. Invention [8] A thermoplastic resin composition for a hydrogen tank liner according to any one of inventions [1] to [7], wherein the semi-aromatic polyamide (B) is polyamide MXD6. Invention [9] A thermoplastic resin composition for a hydrogen tank liner according to any one of inventions [1] to [8], characterized in that the elastomer (C) comprises at least one selected from the group consisting of an acid-modified or epoxy-modified polyolefin-based elastomer, a polystyrene-based elastomer, and an acid-modified or epoxy-modified polystyrene-based elastomer. Invention

[10] A hydrogen tank having a liner made of the thermoplastic resin composition according to any one of inventions [1] to [9]. [Industrial Applicability]

[0033] The thermoplastic resin composition of the present invention can be suitably used as a material for forming a liner for a hydrogen tank.

Claims

1. A thermoplastic resin composition for a hydrogen tank liner, comprising an aliphatic polyamide (A), a semi-aromatic polyamide (B), and an elastomer (C), wherein the aliphatic polyamide (A) has a polymethylene chain having 10 or more carbon atoms sandwiched between two adjacent amide bonds, the aliphatic polyamide (A) and the semi-aromatic polyamide (B) constitute a matrix, and the elastomer (C) constitutes a domain.

2. 2. The thermoplastic resin composition for a hydrogen tank liner according to claim 1, wherein the matrix comprises an aliphatic polyamide (A) phase and a semi-aromatic polyamide (B) phase, and the content of the elastomer (C) in the aliphatic polyamide (A) phase is higher than the content of the elastomer (C) in the semi-aromatic polyamide (B) phase.

3. 2. The thermoplastic resin composition for a hydrogen tank liner according to claim 1, wherein the mass ratio of the aliphatic polyamide (A) to the semi-aromatic polyamide (B) is 95:5 to 40:

60.

4. 2. The thermoplastic resin composition for a hydrogen tank liner according to claim 1, wherein the content of the elastomer (C) in the thermoplastic resin composition is 5 to 50 mass %.

5. Temperature: 270°C, shear rate: 243 s －１ The melt viscosity η of the aliphatic polyamide (A) Ａ Melt viscosity η of semi-aromatic polyamide (B) Ｂ The ratio of η Ｂ / η Ａ 2. The thermoplastic resin composition for a hydrogen tank liner according to claim 1, wherein the tensile strength is 0.20 to 0.

95.

6. Thermoplastic resin composition temperature: 270°C, shear rate: 243 s －１ 2. The thermoplastic resin composition for a hydrogen tank liner according to claim 1, wherein the melt viscosity η is 700 to 1500 Pa·s.

7. 2. The thermoplastic resin composition for a hydrogen tank liner according to claim 1, wherein the aliphatic polyamide (A) is polyamide 11.

8. 2. The thermoplastic resin composition for a hydrogen tank liner according to claim 1, wherein the semi-aromatic polyamide (B) is polyamide MXD6.

9. 2. The thermoplastic resin composition for a hydrogen tank liner according to claim 1, wherein the elastomer (C) comprises at least one selected from the group consisting of an acid-modified or epoxy-modified polyolefin-based elastomer, a polystyrene-based elastomer, and an acid-modified or epoxy-modified polystyrene-based elastomer.

10. A hydrogen tank having a liner made of the thermoplastic resin composition according to claim 1.

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