66 A high strength polyamide 66 multi filament with excellent heat-stability and a process of preparing for the same

摘要

PURPOSE: Provided is a high tenacity polyamide 66 multi filament which involves excellent thermal stability and shearing strength, and is well adapted for use in manufacturing a rubber reinforcing tire cord. CONSTITUTION: A method for manufacturing the high tenacity polyamide 66 multi filament comprises the steps of: condensation-polymerizing hexamethylenediamine and adipic acid to make a polyamide 66 polymer; and melt-spinning it, followed by cooling and multi-stepped drawing. Before the condensation polymerization is completed, 0.01-0.1wt.% of a metallic stearate compound is added to 100wt.% of the hexamethylenediamine. The cooling of the melt-spun polymer is made at 270-320 deg.C by a natural cooling unit directly placed under the spinneret with a length of 250-350mm.