Polyamide resin composition and molded product

摘要

Disclosed is an m-xylene group-containing polyamide resin composition having excellent gas barrier properties and heat aging resistance, which contains (A) a polyamide composed of a diamine unit containing 30% by mole or more of an m-xylylenediamine unit and a dicarboxylic acid unit and (B) an aromatic secondary amine based compound and has an oxygen permeability coefficient of not more than 1 cc·mm/m2·day·atm at 23° C. and 75% RH.

主权项

1. A polyamide resin composition, comprising
(A) a polyamide comprising a diamine unit, comprising 30% by mole or more of an m-xylylenediamine unit, and a dicarboxylic acid unit, (B) an aromatic, secondary-amine-based compound, and (C) an organic, sulfur-based compound wherein a content ratio of the aromatic, secondary-amine-based compound (B) and the organic, sulfur-based compound (C) ((B)/(C) mass ratio) in the polyamide resin composition is from 0.1 to 5.0, wherein the organic sulfur based compound (C) is present in an amount of from 0.2 to 5 parts by mass based on 100 parts by mass of the polyamide (A), and wherein a 100 μm-thick film consisting of the polyamide resin composition has an oxygen permeability coefficient of not more than 1 cc·mm/ 2day·atm at 23 ° C. and 75 % RH, and has a tensile strength retention rate (%) of not less than 92% as calculated according to the following expression (1): Tensile strength retention rate (%) =[{Stress at break (MPa) of film after heat treatment}/{Stress at break (MPa) of film before heat treatment}]×100 (1) where the stress at break (MPa) in this expression is tested in conformity with JIS K7127 by using the film before and after heat treatment at 130° C. for 72 hours.