POLYURETHANE ELASTIC YARN EXCELLENT IN HEAT SETTING PROPERTY AND PROCESS FOR PREPARATION THEREOF

摘要

PURPOSE: Polyurethane elastic yarn having excellent heat setting property and mechanical physical properties after heat setting and a process for producing the same in high spinnability and productivity are provided. Therefore, the elastic yarn can be used for the manufacture of stockings, underwear for women and a swimming suit. CONSTITUTION: The polyurethane elastic yarn is prepared by the following process: polymer glycol and diisocyanate are introduced into a preliminary polymerization pipe in an equivalent ratio of 1:1.62 to 1.66 and prepolymerized at less than 80deg.C to produce a prepolymer; (a)the prepolymer, (b)an extending agent comprising 71 to 80 mol ethylenediamine, 20 to 29 mol 1,2-propylenediamine and 1.1 to 2.0 equivalent diethylenetriamine and (c)a chain terminating agent as diethyleneamine are reacted to produce a secondary polymer solution; and the second polymer solution is dry spun at a velocity of above 750m/min.