Polyamide composition

Abstract

The present invention relates to a polyamide composition comprising (A) polyamide, (B) polyphenylene ether, and (C) an ethylene-α-olefin copolymer prepared using a single site catalyst. The resin composition of the present invention can provide a polyamide composition having excellent impact resistance and excellent surface smoothness, and displaying only small dimensional changes after water absorption.

What is claimed is:  
     
         1 . A composition comprising: 
 (A) 50 to 95% by weight of polyamide based on the total of components (A) and (B);    (B) 50 to 5% by weight of polyphenylene ether based on the total of components (A) and (B); and    (C) 1 to 30 parts by weight, based on 100 parts by weight of the total of components (A) and (B), of an ethylene-α-olefin copolymer prepared using a single site catalyst and/or an ethylene-α-olefin copolymer prepared using a single site catalyst and modified with one or more compounds selected from the group consisting of α, β-unsaturated dicarboxylic acid and derivatives thereof.    
     
     
         2 . The composition according to    claim 1   , wherein component (A) of polyamide forms a continuous phase, and components other than component (A) form dispersed phases which have a number-average distribution diameter of 10 μm or less.  
     
     
         3 . The composition according to    claim 1    or    2   , wherein component (C) of an ethylene-α-olefin copolymer has a molecular weight distribution (weight-average molecular weight/number-average molecular weight) of 3 or less.  
     
     
         4 . The composition according to    claims 1    to    3   , wherein the single site catalyst used for the preparation of component (C) of the ethylene-α-olefin copolymer contains one or more catalysts containing 1 or 3 cyclopentadienyl or substituted cyclopentadienyl molecules.  
     
     
         5 . The composition according to    claims 1    to    4   , wherein an ethylene unit content of component (C) of the ethylene-α-olefin copolymer is 30 to 95% by weight.  
     
     
         6 . The composition according to    claims 1    to    5   , wherein an electroconductive filler is incorporated as component (D) in an amount of less than 10 parts by weight based on 100 parts by weight of the total of components (A), (B) and (C).  
     
     
         7 . The composition according to    claims 1    to    6   , wherein a block copolymer of an aromatic vinyl compound and a conjugated diene compound and/or a hydrogenated product thereof is incorporated as component (E) in an amount of less than 30 parts by weight based on 100 parts by weight of the total of components (A), (B) and (C).  
     
     
         8 . The composition according to    claim 7   , wherein component (E) is a block copolymer of an aromatic vinyl compound and a conjugated diene compound having a content of an aromatic vinyl compound of 15 to 65% by weight and a number-average molecular weight using a polystyrene standard of 80,000 to 300,000.  
     
     
         9 . The composition according to    claims 1    to    8   , wherein the composition contains at least one compatible agent selected from the group consisting of a copolymer comprising an aromatic vinyl compound and α, β-unsaturated dicaroxylic acid and/or derivatives thereof, maleic anhydride, fumaric acid, citric acid and malic acid.  
     
     
         10 . The composition according to    claims 1    to    9   , wherein a part or all of component (B) of polyphenylene ether is modified polyphenylene ether obtained by reacting one or more compounds selected from the group consisting of maleic anhydride, fumaric acid, glycidyl acrylate and glycidyl methacrylate with non-melted polyphenylene ether in the presence or absence of a radical initiator at a temperature from 100° C. to a glass transition point of polyphenylene ether.  
     
     
         11 . The composition according to    claims 6    to    10   , wherein component (D) of the electroconductive filler is an electroconductive carbon black.