MODIFIED ETHYLENIC POLYMER AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain an ethylenic polymer modified with an unsaturated carboxylic acid or its anhydride and provide a method for producing the polymer. SOLUTION: The modified ethylenic polymer is produced by reacting an ethylenic polymer with an unsaturated carboxylic acid or its anhydride under grafting reaction condition. The addition amount of the unsaturated carboxylic acid or its anhydride unit is 0.5-2 wt.%, the content of unreacted unsaturated carboxylic acid or its anhydride is <=30 ppm and the number of fish eyes of the polymer is <=30/g measured by diluting the modified ethylenic polymer with an unmodified ethylenic polymer to obtain a blended polymer having an additional mount of the unsaturated carboxylic acid or its anhydride of 0.25 wt.%. The modified ethylenic polymer is produced by the melt-extrusion using a twin-screw extruder having two or more raw material feeding ports and one or more venting ports, melting and kneading the polymer at a polymer temperature of 200-270 deg.C in the kneading zone and devolatizing through the venting ports.