Method of manufacturing the stereocomplex polylactic acid fiber of low dry heat shrinkage.

摘要

PROBLEM TO BE SOLVED: To provide excellent effects on a fiber product including a stereo complex polylactic acid fiber by setting a crimp performance and shrinkage in a specific range.;SOLUTION: There is provided a method for producing a polylactic acid fiber comprising a poly lactic acid composition that includes: a poly-L-lactic acid including a L-lactic acid as a main component and having a mass average molecular weight of 50,000 to 300,000 (component A); a poly-D-lactic acid including a D-lactic acid as a main component and having a mass average molecular weight of 50,000 to 300,000 (component B); and a specific kind of phosphoric ester metal salt (component C) of 0.05 to 5.0 pts.mass based on 100 pts.mass of the total of the components A and B, and that has a single melt peak in a range of 200 to 230°C and a stereo-formation ratio (Sc-formation ratio) of 90% or more by a wide angle X-ray diffraction method. A method for producing a stereo complex polylactic acid fiber comprises: obtaining an undrawn yarn by melt spinning of a polylactic acid composition; and subjecting to a one-step drawing or a multiple-step drawing including two or more steps in a drawing process, where the one-step drawing is performed in a liquid bath of 20 to 150°C, and subsequently the multiple-step drawing is performed, and then a constant length heat treatment at 20 to 120°C and a relaxation heat treatment at 130 to 165°C for 1 to 120 minutes are carried out.;COPYRIGHT: (C)2012,JPO&INPIT