Polyamide resin composition for extrusion molded products exposed to high-pressure hydrogen, and extrusion molded product

Patent metadata

Field	Value
Publication number	US-11261326-B2
Application number	US-201917262036-A
Country	US
Kind code	B2
Filing date	Jul 29, 2019
Priority date	Jul 31, 2018
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

A polyamide resin composition for an extrusion-molded article exposed to high-pressure hydrogen gas contains: 70 to 99 parts by weight of a polyamide 6 resin (A); 1 to 30 parts by weight of an impact modifier (B); and 0.005 to 1 parts by weight of a metal halide (C) with respect to a total of 100 parts by weight of the polyamide 6 resin (A) and the impact modifier (B). The polyamide resin composition has a melt tension of 20 mN or more when measured at 260° C. and a take-up speed at strand break of 30 m/min or more when measured at 260° C.

First claim

The invention claimed is:

1. An extrusion-molded article adapted to be exposed to high-pressure hydrogen gas, comprising a polyamide resin composition, wherein said polyamide resin composition comprises:
75 to 90 parts by weight of a polyamide 6 resin (A);
10 to 25 parts by weight of an impact modifier (B); and
0.02 to 0.5 parts by weight of a metal halide (C) with respect to a total of 100 parts by weight of the polyamide 6 resin (A) and the impact modifier (B),
wherein the polyamide 6 resin (A) has a relative viscosity (ηr) of 3.3 to 4.4 at a temperature of 25° C. in a 98% sulfuric acid solution having a resin concentration of 0.01 g/ml,
the impact modifier (B) comprising an ethylene/α-olefin copolymer modified with an unsaturated carboxylic acid and/or its derivative,
an amount of the unsaturated carboxylic acid and/or its derivative introduced from the modification is 0.3 to 2.5 parts by weight with respect to 100 parts by weight of the ethylene/α-olefin copolymer modified with the unsaturated carboxylic acid and/or its derivative,
wherein an average dispersion diameter of the impact modifier (B) dispersed in the polyamide resin composition is 0.01 to 0.5 μm, and the polyamide resin composition has 1) a melt tension of 20 mN or more when measured at 260° C., and 2) a take-up speed at strand broke of 50 m/min or more when measured at 260° C.

2. The extrusion-molded article according to claim 1 , wherein the metal halide (C) contains an alkali metal halide and/or copper iodide.

3. The extrusion-molded article according to claim 1 , wherein the extrusion-molded article has a pipe shape.

4. The extrusion-molded article according to claim 3 , wherein a standard deviation of thicknesses of parts obtained by dividing the extrusion-molded article having a pipe shape into four in a circumferential direction is 0.1 or less.

5. A method of producing a high-pressure hydrogen tank liner, comprising producing the extrusion-molded article according to claim 1 , and welding the extrusion-molded article to a molded article made of a resin composition.

Assignees

• Toray Industries

Inventors

• Ochiai Shinichiro
• Suzuki Shota
• Kobayashi Sadayuki

Classifications

• Y02E60/32

  Hydrogen storage · CPC title

• C08G69/14 Primary

  Lactams · CPC title

• Y02P90/45

  Hydrogen technologies in production processes · CPC title

• C08L77/02 Primary

  Polyamides derived from omega-amino carboxylic acids or from lactams thereof (C08L77/10 takes precedence) · CPC title

• B29C48/32

  with annular openings, e.g. for forming tubular articles · CPC title