Multi-phase structure and process for producing the same

摘要

A polyamide resin composition having a multi-phase structure and a process for producing the same are disclosed, the composition comprising: (A) from 60 to 97 parts by weight of a polyamide resin containing at least 2 parts by weight of (A-1) a polyamide resin having a concentration ratio of terminal carboxyl group to terminal amino group of 1.5 or more, (B) from 3 to 40 parts by weight of an ethylene copolymer comprising: (a) from 40 to 90% by weight of an ethylene unit, (b) from 5 to 60% by weight of an (alpha),(beta)-unsaturated carboxylic acid alkyl ester unit, and (c) from 0.3 to 10% by weight of a maleic anhydride unit, and (C) from 0.01 to 20 parts by weight, per 100 parts by weight of the sum of the components (A) and (B), of a polyfunctional compound having at least two functional groups reactive to a carboxylic anhydride group or a carboxyl group in the molecule thereof, a part of the polyamide resin (A) constituting a matrix phase, the ethylene copolymer (B) constituting a first-order disperse phase, and the rest of the polyamide resin (A) constituting a second-order disperse phase in the first-order disperse phase. The composition has well-balanced physical properties, such as impact resistance, rigidity, and thermal resistance, and excellent moldability. A process for producing the above multi-phase structure is also included, in which a part of a polyamide resin constitutes a matrix phase, an ethylene copolymer constitutes a first order dispersed phase, and the rest of the polyamide resin constitutes a second order dispersed phase in the first order dispersed phase.